design automation of steam turbine diaphragms in nx

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Linköping University | Department of Management and Engineering Master thesis, 30 credits | Master of Science – Mechanical Engineering Spring 2021 | LIU – IEI – TEK – A -- 21/04089 – SE Design Automation of Steam Turbine Diaphragms in NX ___________________________________________________ Research and implementation of design automation in a development process Emil Tellsén Supervisor: Erik Ernstsson, Siemens Energy Mehdi Tarkian, Linköping University Examiner: Johan Persson, Linköping University Linköpings universitet SE-581 83 Linköping Sverige 013-28 10 00, www.liu.se

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Page 1: Design Automation of Steam Turbine Diaphragms in NX

Linköping University | Department of Management and Engineering

Master thesis, 30 credits | Master of Science – Mechanical Engineering

Spring 2021 | LIU – IEI – TEK – A -- 21/04089 – SE

Design Automation of Steam Turbine Diaphragms in NX ___________________________________________________ Research and implementation of design automation in a development process

Emil Tellsén

Supervisor: Erik Ernstsson, Siemens Energy

Mehdi Tarkian, Linköping University

Examiner: Johan Persson, Linköping University

Linköpings universitet

SE-581 83 Linköping Sverige

013-28 10 00,

www.liu.se

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Abstract

Siemens Energy develops, manufactures, and provides service of products utilized for

production of green energy. This thesis has been conducted at Siemens Energy in Finspång and

the department of steam turbine design. A major part of the work at the department includes

service and updates of operating steam turbines located all around the world. The tasks of

updating and service are short and require quick answers as the plant is waiting to be started. In

order to adapt to the rapid development time required, the department of steam turbine design

has developed a CAD automation process for drawing production of steam turbine diaphragms.

The automation process is developed in an older CAD system that the department long have

relied on. This CAD software and thus the automation process will soon be retired and taken

out of service since the company is switching to the modern CAD software NX. This thesis is

aimed at investigating the current development process at the department and propose and

develop a new CAD automation process in NX for steam turbine diaphragms.

The work was initiated by performing an analysis of the current situation where the collection

of data constituted a solid ground for the rest of the thesis. The data lay the basis for the creation

of a design specification which later served as a starting point for both the search and

development of solution proposals regarding CAD automation. During the concept generation,

it became clear that the development process embodied the scope of concepts, a form of

application programming interface to achieve design automation was considered evident. This

implied a more area-focused concept generation leading up to multiple solution concepts. After

the generated solutions had been sorted and ranked, the solution to proceed with was based on

NX integrated tool Knowledge Fusion to achieve CAD automation in NX. The development of

the automation process and associated models utilized theories such as the MOKA

methodology, high level cad templates and on explicit reference modeling. Resulting in a CAD

automation process with possibilities to deliver both CAD models and technical drawings

within a timeframe that reduces development time.

It was concluded that the developed CAD automation process and associated models assured

quality and reliability of the CAD material produced. Furthermore, the developed solution fit

in the existing diaphragm development process and showed potential to significantly reduce the

development time of steam turbine diaphragms.

Key words: Design automation, CAD, Process development, Knowledge based engineering,

NX

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Preface This master’s thesis was conducted at Siemens Energy AB in Finspång during the spring of

2021. The thesis represented the final part of the master’s program of Mechanical Engineering

at Linköping University and covered 20 weeks of work, corresponding to 30 ECTS.

I would like to take this opportunity to thank Siemens Energy and all the employees at the

department who have helped me throughout the work with my master thesis, ranging from

answering simple questions and emails to participating in interviews. A special thanks to Erik,

Thomas, Johan and Ted who have helped me during the work and contributed with technical

expertise and made my work at Siemens Energy possible.

Then I would like to thank Linköping University and my supervisor Mehdi Tarkian, who has

inspired and guided me through his courses and supervision in the subject of design automation.

Finally, I would like to thank my opponent and friend Henrik Müller-Wilderink for constructive

criticism and feedback which gave me new insights that helped improve my work.

Linköping, June 2021

___________________

Emil Tellsén

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Abbreviations

AD Axial Dimension

API Application Programming Interface

CAD Computer Aided Design

CW Clockwise

CCW Counterclockwise

EBW Electron Beam Welding

GDA Geometry based Design Automation

GUI Guided User Interface

GV Guide Vane

HLCts High Level CAD templates

HP High Pressure

IP Intermediate Pressure

KBE Knowledge Based Engineering

KF Knowledge Fusion

LP Low Pressure

MOKA Methodology and software tools Oriented to KBE Applications

PLM Product Lifecycle Management

R&D Research and Development

RD Radial Dimension

RQ Research Question

SNAP Simple NX Application Programming

SST Siemens Steam Turbine

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Table of contents

1 INTRODUCTION ............................................................................................................ 1

1.1 Company ...................................................................................................................... 1

1.2 Problem formulation .................................................................................................... 2

1.3 Purpose and Objective ................................................................................................. 3

1.4 Research question ........................................................................................................ 4

1.5 Delimitations ............................................................................................................... 4

1.6 Thesis outline ............................................................................................................... 4

2 THEORY ........................................................................................................................... 6

2.1 General problem-solving process ................................................................................ 6

2.2 Research methods ........................................................................................................ 7

2.3 Interview methodology ................................................................................................ 7

2.3.1 Structured interview ...................................................................................................................... 8

2.3.2 Unstructured interview ................................................................................................................. 8

2.3.3 Semi-structured interview ............................................................................................................. 8

2.4 Design criteria management ........................................................................................ 9

2.5 Solution finding methods............................................................................................. 9

2.5.1 Information gathering ................................................................................................................. 10

2.5.2 Analysis of existing technical systems ........................................................................................ 10

2.6 Knowledge-based engineering .................................................................................. 10

2.7 Parametrization .......................................................................................................... 12

2.8 High level CAD modelling ........................................................................................ 14

2.9 Design automation ..................................................................................................... 16

2.10 Software testing and quality assurance ...................................................................... 18

3 METHOD ........................................................................................................................ 19

3.1 Problem analysis and definition ................................................................................ 19

3.1.1 Theoretical reference frame ........................................................................................................ 19

3.1.2 Data gathering ............................................................................................................................. 19

3.1.3 Cost analysis ............................................................................................................................... 20

3.1.4 Process mapping of preceding steps ........................................................................................... 21

3.2 Criteria specification .................................................................................................. 22

3.3 Concept generation .................................................................................................... 22

3.4 Concept evaluation and selection .............................................................................. 23

3.5 Realization ................................................................................................................. 23

3.5.1 Capture ........................................................................................................................................ 23

3.5.2 Formalize .................................................................................................................................... 24

3.5.3 Package ....................................................................................................................................... 24

3.6 Analysis ..................................................................................................................... 25

4 RESULTS ........................................................................................................................ 26

4.1 Problem analysis and definition ................................................................................ 26

4.1.1 Data gathering ............................................................................................................................. 26

4.1.2 Cost analysis ............................................................................................................................... 27

4.1.3 Process map ................................................................................................................................ 29

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4.2 Criteria specification .................................................................................................. 30

4.3 Concept generation .................................................................................................... 32

4.3.1 Analysis of existing system – Cadds5 ......................................................................................... 32

4.3.2 Analysis of existing system – NX ............................................................................................... 33

4.3.3 Information gathering – NX programming ................................................................................. 35

4.3.4 Information gathering – Program from external contractor ........................................................ 36

4.3.5 Solution concepts ........................................................................................................................ 36

4.4 Concept evaluation and selection .............................................................................. 37

4.5 Realization ................................................................................................................. 38

4.5.1 Capture ........................................................................................................................................ 38

4.5.2 Formalize .................................................................................................................................... 41

4.5.3 Package ....................................................................................................................................... 44

4.6 Analysis ..................................................................................................................... 50

5 DISCUSSION ................................................................................................................. 54

6 FURTHER WORK ........................................................................................................ 57

7 CONCLUSION ............................................................................................................... 58

7.1 RQ1 ............................................................................................................................ 58

7.2 RQ2 ............................................................................................................................ 59

8 REFERENCES ............................................................................................................... 60

APENDIX

A: Interview summaries

B: Technical drawings

C: Time measurements

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Table of figures

Figure 1: Steam turbine of the VAX type, high pressure turbine to the left, low pressure turbine

to the right and a generator in the middle. Asset: Siemens Energy. ........................................... 2

Figure 2: Steam turbine diaphragm including the components Inner- and outer ring, inner and

outer guide vane strip and guide vane. Asset: Siemens Energy. ................................................ 3

Figure 3:Divergent problem-solving process with five main phases, Problem definition, Criteria

definition, Concept generation, Evaluation and selection and Implementation adapted from [5].

.................................................................................................................................................... 6

Figure 4: Fictive example of a Knowledge Based Engineering system adapted from [16]. .... 11

Figure 5: Life cycle of a KBE system according to [16]. ........................................................ 11

Figure 6: Modeling operations and their relations based on explicit reference modeling

according to [20]. ..................................................................................................................... 13

Figure 7: Classes of problems dividing the design process compared to the classic design

approach adapted from [21]. .................................................................................................... 13

Figure 8: Morphological transformation pyramid displaying the different stages. Asset:

Amadori [19]. ........................................................................................................................... 15

Figure 9: Topological transformation pyramid displaying the different stages. Asset: Amadori

[19]. .......................................................................................................................................... 16

Figure 10: Example of geometry-based Design Automation process adapted from [19]. ....... 17

Figure 11: General outline of the main activities performed in the method for this thesis. ..... 19

Figure 12: Example of the different drawing annotations that was considered in the drawing

analysis. .................................................................................................................................... 21

Figure 13:Process map of the preceding activities to the CAD automation activity. ............... 29

Figure 14: General process map of the CAD automation process in Cadds5. ......................... 33

Figure 15: General process map of the CAD automation process in NX. ............................... 34

Figure 16: One common framework APIs supported by NX, adapted from [27]. ................... 35

Figure 17: Process map of CAD automation process showing where solution alternatives in the

form of a program or API can be implemented. ....................................................................... 36

Figure 18: Diaphragm in two views, displaying a simplified view of the main components

included. ................................................................................................................................... 38

Figure 19: Captured knowledge for the outer guide vane strip. ............................................... 39

Figure 20: Captured knowledge for the inner guide vane strip. ............................................... 40

Figure 21: Captured knowledge for the guide vane. ................................................................ 40

Figure 22: General structure and strategy of the automation process and how information is

transmitted. ............................................................................................................................... 41

Figure 23: The structure and hierarchy of the KBE model as well as its connection to the

imported parameters inside NX. ............................................................................................... 43

Figure 24: Flowchart displaying the logic behind the rules and functions that each component

retrieves from the Interpart expression. .................................................................................... 44

Figure 25: Example of a small diaphragm configuration displaying geometry variation. ....... 46

Figure 26: Example of a medium diaphragm configuration displaying geometry variation. .. 46

Figure 27: Example of a large diaphragm configuration displaying geometry variation. ....... 47

Figure 28: Outer guide vane strip, technical drawing created by the CAD automation. ......... 48

Figure 29: Inner guide vane strip, technical drawing created by the CAD automation. .......... 48

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Figure 30: Guide vane, technical drawing created by the CAD automation. ........................... 49

Figure 31: Inner guide vane strip, clippings of drawing displaying two outline configurations,

flat to the left and conical to the right. ..................................................................................... 50

Figure 32: Outer guide vane strip, clippings of drawing displaying two guide vane cut-out

configurations, CCW rotation to the left and CW rotation to the right. ................................... 50

Table of tables

Table 1: Drawing analysis of diaphragm. ................................................................................. 28

Table 2:Time measurements and estimations regarding development for different diaphragm

components. .............................................................................................................................. 28

Table 3:Design specification for the diaphragm design automation process in NX. ............... 31

Table 4: Criteria weight matrix of the generated concepts. ...................................................... 37

Table 5: Quality verification of the CAD automation and the performed test cycles. ............. 51

Table 6: Time measurements regarding the components outer guide vane strip, inner guide vane

strip and guide vane for the different subparts of the process. ................................................. 52

Table 7: Time comparison comparing manual work, the automation process in Cadds5 and the

automation process in NX regarding the models and drawings: Inner and outer guide vane strip

and guide vane. ......................................................................................................................... 53

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1 Introduction

With an increasing population and global warming that is continuously growing, the demand

for renewable and environmentally friendly energy has never been greater. The question of how

renewable energy can meet human needs is still unanswered. At the same time, technological

development is advancing and companies around the world need to adapt to the ever-changing

environment to stay competitive and reach the top of the market. High quality products must

be manufactured at lower prices and within a reasonable time frame.

In large parts of the world, electricity in the home is taken for granted. In order to maintain such

energy consumption, electricity-producing power plants must be updated and serviced to

sustain the energy production. The maintenance stops for service and repair are kept as short as

possible to keep the energy production uptime as high possible. High demands are put on

producers of spare parts and updates, new parts must be developed and produced within short

timeframes. With short development times and tight schedules, the key is to reduce repetitive

work to speed up the development process.

1.1 Company

Siemens Energy AB was formed in 2020 and is an independent company formed from a break-

out of the energy sector from the parent company Siemens AG. Siemens Energy have 91,000

employees worldwide located in more than 90 countries. In Sweden, Siemens Energy has 2,600

employees in ten locations, among other, in Finspång, Trollhättan, Eskilstuna and Örebro [1].

The Swedish headquarter of Siemens Energy is located in Finspång, which develops,

manufactures and services turbines for the global energy market in their facilities. Siemens

Energy in Finspång is a big player in today’s industry with its main focus on gas turbines and

renewable fuel for energy generation [2].

The company name Siemens Energy is young, but the history behind the company and the

development and manufacturing of turbines in Finspång reaches back in time. The production

of turbines was started in Finspång 1913 under the company name STAL, the first turbines that

were produced were radial steam turbines marketed as a stationary steam turbine that was used

for generator operation. At the end of the 50’s, STAL and its competitor Laval merged to create

the company Stal-Laval. A total of 328 steam turbine machinery was delivered. In 1973 the era

of steam turbines ends; the oil crisis favors diesel engines and steam turbines are displaced.

Instead, a long period of deliveries to the Swedish and Finnish nuclear power programs begins.

Of a total of 18 steam turbine lines in Swedish nuclear power plants, 16 was delivered from

Finspång. In the beginning of the new millennium, steam turbines have found a new niche to

dominate, namely the one for large solar power plants, a market outside of Sweden for natural

reasons. [3]

Globally, Siemens Energy offers solutions, services, and products throughout the complete

energy chain. The range of solutions, services, and products that Siemens Energy offers can be

divided into five categories, Transmission, Generation, Industrial application, New energy

business and Siemens Gamesa renewable energy. [4]

This thesis will be conducted at Siemens Energy in Finspång and the department of steam

turbine design. Originally, the entire chain for steam turbines existed in Finspång, from

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development to aftermarket. Today only service remains, the rest was moved to

Görlitz/Erlangen in Germany. The service division is a growing business area within Siemens

Energy that has the whole world as its field of work. The technical offices at the department for

service industrial steam turbine work, among other things with technical sales support,

development of service products, problem solving, suggestions for improvement and feedback

of experience. Rebuilding and adapting the turbines to the customers' is important tasks that

often generates large orders. Many tasks are short and require quick answers as the plant is

waiting to be started.

1.2 Problem formulation

Siemens steam turbines of the VAX type were developed in the early 1980s, today the name for

these turbines is Siemens Steam Turbines (SST) 700/900. The concept consists of an alternating

high pressure (HP) and low pressure (LP) turbine with a generator in the middle, see Figure 1.

To date, about 350 plants with this type of turbine have been delivered to locations all around

the world. Until 2015, the Computer Aided Design (CAD) program Cadds5 was used as a

design tool for generating drawings. After that have Siemens Energy gradually switched to the

modern CAD program NX as Cadds5 is an outdated tool that is on its way out of the market.

Figure 1: Steam turbine of the VAX type, high pressure turbine to the left, low pressure turbine to the right and a

generator in the middle. Asset: Siemens Energy.

Over the years, customers of Siemens Energy have changed conditions for their steam turbine

operations. This implies that the inner parts of the turbine must be rebuilt and replaced to meet

the new conditions, this mainly affects the rotor and diaphragm of the steam turbine, see Figure

2. Work was done in the steam turbine research and development department (R&D) to produce

automatically generated drawings for rotors and diaphragms in the design tool NX. In 2011, the

R&D department for steam turbine was moved from Finspång to Germany and the work with

CAD automation regarding drawings and models was not completed. Projects attempting to

create automated diaphragm drawings and models in NX has been initiated and ongoing but

has never been finished in a successful way. The department of steam turbine design have

continued to produce these drawings via Cadds5, but this program will be excluded completely

within a year.

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Figure 2: Steam turbine diaphragm including the components Inner- and outer ring, inner and outer guide vane

strip and guide vane. Asset: Siemens Energy.

To avoid repetitive and time-consuming tasks. As it is to manually produce all drawings for

diaphragms. Siemens Energy and the department of steam turbine design requires a replacement

program in NX for automatic generation of drawings and models. Nearly all steam turbines are

one of a kind and have unique diaphragms. In an order to update or rebuild a steam turbine,

there can be over 20 diaphragms which accumulates a total of over 200 drawings in need of

quick development. An automation process for CAD files has the potential to increase the

effectivity of work and reduce development time.

1.3 Purpose and Objective

The purpose of this thesis is to develop an automation process for creation of CAD files used

for manufacturing. This will be achieved by creating parametric models that can assume

different shapes depending on its input. The diaphragms have a fixed number of components,

implying that a set number of parametric models will be created and utilized. However, the

components in the diaphragm can show large geometrical variation which should be considered.

The developed solution should increase the efficiency in the work of the designers and be

applicable with programs used by Siemens Energy today. The previously created automation

process in Cadds5 reduced diaphragms development time with 30% in comparison to manual

work. Achieving similar time decrease will be aimed for when developing an automation

process in NX.

This thesis will examine the department of steam turbine designs need of CAD files used for

manufacturing of diaphragms, analyze existing procedures for automation, research new

methods for automation, compare and pick the best suitable option and start developing a CAD

automation process for manufacturing basis. Following objectives were stated to fulfill the

purpose:

− Research, present and decide the best suitable way for CAD automation for steam

turbine diaphragms.

− Develop an overall structure for how to automatically generate diaphragm

manufacturing basis in the CAD tool NX.

− Aim for one or more parts/drawings in the diaphragm for CAD automation.

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1.4 Research question

The following research questions (RQ) were formulated to guide the research for developing a

method suitable for CAD automation:

− RQ1: How can a CAD automation process for diaphragms at a steam turbine developer

be designed to reduce repetitive work and decrease the development time?

− RQ2: How can a CAD automation process be integrated in the already existing

development process for diaphragms of steam turbines and ensure quality?

1.5 Delimitations

The thesis project includes both research and development, earlier parts lean more towards

research while the later parts are development. When developing an automation process, this

thesis will start implementation on steam turbine diaphragms. It is not reasonable for this project

to complete the automation process for the whole steam turbine diaphragm.

This thesis will only look at the CAD automation process. Calculations and parametrization

located earlier in the development process will be utilized in the form of parameter values but

not investigated further. Furthermore, the design automation process should not be designed to

explore the geometrical space through means of optimization, but rather take the shape and

change geometry depending on parameter values from the calculation program.

The CAD automation process should be built for steam turbine diaphragms and specifically

standardized electron beam welding (EBW) steam turbine diaphragms and the latest technology

type. The CAD program used for automation will be NX.

1.6 Thesis outline

The thesis’ outlines and main chapters are presented briefly below.

Chapter 2 – Theory relevant to the thesis are presented. The theories presented are initially the

methods and tools applicable to this project, following are the theories necessary for realizing

the solution proposals. The main topics encountered in this chapter are research methods, design

automation and CAD modeling allowing design automation.

Chapter 3 – Method and tools used for the thesis are presented and described, including

problem definition/analysis, criteria specification, concept generation, evaluation and selection

of concepts, realization of the selected concept and lastly analysis of the results implying time

and quality evaluation and testing.

Chapter 4 – Results of the thesis are presented, including the problem analysis and definition,

criteria specification, concept generation, evaluation and selection of concepts, realization of

the selected concept and analysis of the results implying time and quality evaluation and testing.

Chapter 5 – Discussion of the chosen method and the derived results. The tools and methods

used and their influence on the result is discussed, following is a discussion of the results.

Chapter 6 – Further work to extend or possibly improve the developed CAD automation

process of steam turbine diaphragms is presented.

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Chapter 7 – Conclusions regarding the performed work and results of the thesis is presented.

Thesis goals, deliverables, specification, and research questions are the basis for the conclusions

drawn.

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2 Theory

In this chapter, relevant theories to the thesis are presented. The theories presented are initially

the methods and tools applicable to this project, following are the theories necessary for

realizing the solution proposals. The main topics encountered in this chapter are research

methods, design automation and CAD modeling allowing design automation,

2.1 General problem-solving process

Design and development problems are often complex and cannot be solved solely based on

intuition. A more systematic approach may be necessary, generally starting by defining sought

after functions and characteristics for the product/process to be developed. In other words, what

the future product/process and its component parts should accomplish. Solutions that have the

potential to meet the identified requirements are then researched. By applying a more systematic

approach, it enables documentation and provides a better overview for everyone involved. [5]

The definition of a problem can be vague and difficult to interpret, Pahl et al. in [6] defines that

a problem has three components. The three components and their meaning are described

accordingly:

− The current situation is unsatisfactory, improvements to enhance the current situation is

possible.

− There exists a desired goal state, a realization of a situation that is satisfactory in ways

that the current is not.

− Obstacles that obstruct change from the undesirable starting state to the wanted

objective state at a specific point in time.

An obstacle obstructing change to the wanted objective state can arise from the three following

reasons. The first one being that method to overcome the obstacle must be discovered since it

still is unknown, these are called synthesis or operator problem. The second one is characterized

by known means, but the numerous amounts of combinations make a systematic investigation

impossible. For the third and last one, vague and not clearly formulated goals are known.

Solutions are found through a process of continuous reflection and removal of conflicts until a

satisfactory situation has been reached. [6]

Development of product/process and design process is a form of structured problem solving. It

can be described as an interaction between synthesis and analysis. The divergent problem-

solving process can be described according to Figure 3.

Figure 3:Divergent problem-solving process with five main phases, Problem definition, Criteria definition,

Concept generation, Evaluation and selection and Implementation adapted from [5].

The first step included in the problem-solving process is the problem analysis/definition. The

purpose of the problem analysis/definition is to methodically work through the problem

formulation, and by doing so, identify all the conditions and background information for the

problem. Background information can be gathered in numerous ways, both internal and

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external, through market analyzes, competitor analyzes and literature review. In the following

step, formulated needs are translated into more technical criteria which forms the criteria

definition and specification. The presentation of criteria may differ and can be expressed as

functional and restrictions or demands and wishes. With the criteria definition and specification

as a starting point, the concept generation phase is initiated as a creative synthesis process. The

goal is to identify solutions to meet the criteria set up in the specification. The solution

alternatives are then evaluated against the criteria and the solution that best meets the criteria is

selected as the solution to be further developed. According to this model, there are no iterations,

but it presumes that there are solutions that meet the criteria among the identified solutions. If

this is not the case, a new iteration will start where new solution alternatives that meet the

criteria can be identified. [5]

2.2 Research methods

The process of research is to systematically collect, analyze and interpret data, each research

method is individually shaped to fit and investigate a specific research problem or area. To be

deemed reliable, the research should be in accordance with existing guidelines. These should

give the researcher an indication of the scope of the research, execution, and what conclusions

can be drawn from the gathered data. The chosen method should be based on the researcher’s

anticipation of the necessary data to answer the research question(s). Quantitative and

qualitative research methods are the two common approaches, a combination of both is also an

alternative approach [7]. Both qualitative and quantitative research methods have weaknesses

and strengths, which for these two, to some extents are contradictory [8].

In a qualitative research, the object is to obtain illustrative and in-depth data to gain deepened

understanding of a given problem. Individual opinions and experiences can be provided and

give an understanding of feelings. Numerical data is not sought after, instead understanding and

explanation of the relationship between social relations is of importance. Even though the

collected data from a qualitatively research method is not quantifiable, statistically majority in

answers can be interpreted and quantified. [9]

Quantitative research uses structural procedures to collect objective data in a systematically

way. The method is best suitable when parameters and inferences can be collected in quantified

measures from samples and populations. Through statistical procedures, the numerical data is

analyzed [9]. The data collected in quantitative research is typically numeric, the researcher

tends to analyze the data through means of mathematical modelling. Gathered data in the

quantitative research is utilized to objectively measure reality, which produces meaning to this

research method. This is a consequence of the research independence of the researcher [7].

2.3 Interview methodology

Interviews is a common research technique usually performed between two people through

conversation. The conversation has a particular purpose where one person, the interviewer,

seeks answers or data from the other person in the conversation, the interviewee. Contrasts

between normal conversations and the interview is the relationship between the interviewer and

the interviewee and how the conversation is controlled. Control is a fundamental part in a

successful interview, even so a nondirective interview strategy contains some elements of

control and direction of the subject [10]. Interviews often generates qualitative data, but with

an interview strategy with more control, quantitative research data can be obtained. It is of

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importance that the gathered data from the interview is unbiased, for this, the process and the

interviewer’s behavior must be considered and planned. Among other things, the interviewer

should be well read in relevant topics, carefully choose questions and who to interview, how

many people should be interviewed and the approach of the interview. Different interview styles

and approaches are determined by the purpose of the interview [11].

2.3.1 Structured interview

The structured interview is controlled and allows little deviation in the gathered data. The

interviewer has pre-determined questions and the responses from the interviewee are limited

and categorized in pre-existing categories. This makes it possible to quantify the results of the

gathered data since it is straight forward to sort out and arrange. The structured interview is

robust in its process. The interviewer reads from a script and asks the same questions in the

same order to all interviewees and avoids as much deviation from the script as possible. The

focus of the structured interview is to obtain quantitative and objective findings, the researcher

is not active in the conversation, thus minimizing researcher bias in the answers of the

interviewee. The questions are designed by the interviewer who has an active role in this

process, the questions and their formulation could affect the findings and be bias towards the

researcher. Standardized and structured methods for avoiding such issues is used to minimize

the probability to achieve unobjective data. [11]

2.3.2 Unstructured interview

On the other side of the spectrum lies unstructured interviews. The degree of structure in the

approach is connected to a few questions that are prepared beforehand corresponding the

research area and purpose of the research. The questions are open-ended, and the interviewee

is encouraged to continue talking about areas and subject that feel relevant and important for

them. The interviewee leads the conversation through their own reasoning, the interviewer can

direct the conversation towards some of the few themes, but generally follows the direction of

the interviewee. [12]

2.3.3 Semi-structured interview

Between the two extremes, being structured and unstructured interviews, a multitude of

interview approaches with varying control and structure are scattered. The most common and

intermediate technique regarding control is the semi-structured interview [12]. The questions

for the semi-structured interview are prepare beforehand and should be constructed to stimulate

and give room for the interviewee to elaborate further on the topic. Follow up question complies

to the theme of the first question to guide the conversation within the framework of the topic.

The amount of guidance and freedom of the questions is much dependent on the purpose and

the approach of the researcher, both highly scripted and relatively loose approaches are used.

The semi-structured approach is beneficial in multiple aspects. It is flexible, accessible,

intelligible and gives the researcher an opportunity to discover facets of humans and

organizations that otherwise might be hidden. The focus lays in the answers of the interviewee

and more precise experiences and thoughts, resulting in qualitative data [13].

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2.4 Design criteria management

In the process of solving problems by developing new solutions, criteria are often set for what

the developed solutions are required to or should fulfill. The purpose of the product

specification is to deepen the knowledge in the product development project by collecting the

necessary supplementary information that is missing from the problem definition/analysis. The

main question that should be answered is “what should be achieved” and “what is limiting

potential solutions”. This should be done in such a way and described in such terms that the

detailed information can be used both as a starting point in the subsequent search for solutions

and as a reference in the evaluation of these solutions. [5]

When managing criteria and requirements to be used in a specification, it is important to clearly

elaborate the goals and how they are expected to be fulfilled, and under which circumstances.

Therefore, the requirements should be identified and categorized as demands or wishes.

Requirements characterized as demands must be fulfilled under all circumstances. If a

requirement is not fulfilled by a solution, the solution is deemed unacceptable. For instance,

qualitative demands could be expressed as “corrosion resistance”, “waterproof” etc.

Requirements characterized as wishes do not have to be fulfilled and should be taken into

consideration whenever possible. Thus, a product solution must meet all the set requirements

completely to be classified as a possible alternative, while different possible solution

alternatives can fulfill different wishes to varying degrees. [6]

There are numerous ways of gathering and taking decisions upon which requirements to include

in the specification. Some general guidelines for composing the specification exist:

− Requirements that were originally given to describe and delimit the task and is included

in the pre-conditions.

− Requirements that are identified through analyzes and clarification regarding the task.

− Requirements as a result of decision making along the development process.

Identifying requirements through analysis of the task can give insight in undiscovered

requirements, a method to accomplish this is to collect data from stakeholders. In this context,

stakeholders may be anyone who will encounter the product/process and may have an opinion

and a point of view. The stakeholders can be individuals or groups within the company,

everyone, or part of the organization, internal or external of the company. Requirements and

wishes from all these stakeholders must be collected and considered when the specification is

established. Other common methods are checklist and scenarios. [5]

2.5 Solution finding methods

The process of finding and generating solutions begins with set solution criteria in the form of

a specification, and results in solution concepts that have the potential to solve the problem. A

successfully performed solution generation leaves the participants confident, the alternatives

explored will solve the problem and the full space of alternatives have been explored. A

structured approach reduces the risks and encourages the collection of information from

different references. Sources of error are predominant, potential occurring errors are too few

solution alternatives have been considered, solution searching has not been made on a

sufficiently broad front or failing to realize categories of solutions. [14]

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2.5.1 Information gathering

The method information gathering is simple and rational, it provides support for creative

thinking and is suitable for problem solving in both group and individual work. The method

involves either systematic or unsystematic fact-finding on how others have succeeded in

solving the current, similar, or related problem. More unsystematically, inspiration and ideas

can be sought in new methods, techniques or trends that could help solve the problem. Sources

of information can be books, journals, articles, patents, publications, internet etc. [5]

2.5.2 Analysis of existing technical systems

Through systematical investigation, analysis of existing technical system is an important

method for identifying and generating new or improved variants of solutions in a systematic

manner. The approach follows the name, existing technical systems are analyzed and dissected,

both mental and physical, in the search for sought partial or complete solutions in the form of

related, logical, physical and embodiment design features. Potential existing systems to be

analyzed for solutions might be any of the following [6]:

− Systems from competitors or other external sources.

− Old or retired systems within one´s own company.

− Systems with similarities where subfunctions or components in the system correspond

to the sought solution.

This method builds on and analyzes existing solutions and experiments by systematically

exploit already proven ideas. In early stages for finding solution, this method has proved to be

intuitive and served as a starting point for further solution variation. However, the search and

use of existing solutions can menace designers to not discover new solutions. [6]

2.6 Knowledge-based engineering

In today's industry and in the international market, companies are looking for opportunities to

gain competitive advantages towards their competitors. Many companies are using similar

systems and processes within finance, logistics and management. The competitive difference is

created in the company knowledge and how it is embedded into systems. One method of

preserving knowledge in the manufacturing industry is Knowledge-Based Engineering (KBE).

A KBE system can be used to reduce lead times for components and products within

development and production. Example of such possibility is to embed model knowledge and

techniques where the design process can be shortened or even automated. [15]

The manufacturing industry has always used knowledge to develop and manufacture products.

Knowledge has traditionally been stored through books, reports, drawings and in digital

systems. The same knowledge as in traditional methods is collected in KBE, the difference is

that knowledge base stored within a software. None of the traditional systems for storing

knowledge enables building a tool into a system that can assist collaboration of engineers in

development. A knowledgebase allows different engineers to utilize and make use of the shared

knowledge. Sainter et al. in [15] defines a Knowledge Based Engineering system as:

“A system that captures product knowledge and the skills of an individual within an engineering

domain, incorporates them and makes them available within a computerized application.”

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The information and data stored in the database is not expressed as specific data instances like

measurements and dimensions as it would be in a Computer Aided Design (CAD) tool, instead

rules and functions are expressed to convey the knowledge. This allows the knowledge to be

applied and used on a larger basis of product variants. Selectively parts of the knowledge base

can be executed to solve similar design problems. The user provides input to the system in the

form of data, which could originate from various sources. Figure 4 visualizes an example of a

KBE system. The input data is managed by the engineering knowledge in the form of rules and

function stored in the product model. The rules are the basis for KBE and all the data that is

stored, programmed expressions through function statements create the rules, complex

expressions and relationships can be created by seemingly simple rules. This generates the

output by the KBE system. [15]

Figure 4: Fictive example of a Knowledge Based Engineering system adapted from [16].

To develop KBE systems and applications, there are several methods that supports this process.

The most well-known approach is Methodology and software tools Oriented to Knowledge-

Based Engineering Applications, or MOKA methodology as it is also called. The method is

based on the steps in the KBE life cycle and developed to serve as an international standard for

the development of KBE systems. The steps in the KBE life cycle are the following: Identify,

Justify, Capture, Formalize, Package and Activate knowledge, see Figure 5. [16]

Figure 5: Life cycle of a KBE system according to [16].

The parts included in the life cycle can be described as follows [16]:

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− The Identify stage is determining needs as well as the technical feasibility.

− Justify validates the scope and assesses possible risks.

− Capture, collect, and structure the raw knowledge.

− Formalize enables the development of product and process models.

− Package is where the application is developed.

− Activate is where the knowledge base is introduced, used, and maintained.

The KBE system is formed by the comprehensive steps from the life cycle, this includes, among

other things, its supervision and control. The creation and development of a KBE life cycle can

often be described as a detailed description of itself. This can be applied even though a method

does not always include all steps in the process but only describes a few of them [17].

2.7 Parametrization

Development processes are reducing in time, something that puts higher demands on the tools

used. A common tool when developing products is to utilize a CAD system. Time reducing

requirements entail an efficient use of the CAD system and methods that support this. Modern

CAD systems facilitate the knowledge and allow the user to create fully parametric and

adaptable models. The word parameter will be used extensively throughout the thesis and a

clear definition is advantageous. A parameter is defined as an independent input that can control

the geometric features of a model. Parameters are also generated as outputs from the model.

Furthermore, parametric CAD models are in this thesis defined as Bodein et al. stated in [18]:

“Geometrical representation of products where certain characteristics are controlled by non-

geometric features called parameters”

When a parametric model is to be developed, the designer is required to make decision

regarding the model and the parameter approach. It is important to keep in mind what the model

should be used for, who should use it, how it should be used, and if there is other software that

will be involved or connected. These conditions have a great influence on the choice of

parameters and the parameter approach when modeling [19]. The existing literature in the field

of CAD parameterization is broad, however, many of the methods differ and the choice of

method often depends on the situation and complexity of the geometry. Explicit reference

modeling method provides a 3D modeling guide describing which constraints can be associated

to a particular shape existing in parametric CAD systems to facilitate reusability, see Figure 6.

[20]

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Figure 6: Modeling operations and their relations based on explicit reference modeling according to [20].

The parametric constraints are divided into two groups, category I and category II. Category I

contains constraints that can be defined without referencing to the model geometry. Among

other features, extrudes, revolve and holes can be created through referencing to 2D sketches

based on planes and reference datums. These are not included in the geometry and is therefore

classified as category I. Category II contains features that must be referenced to existing model

geometry, features included in category II are among others fillets and chamfers which requires

a link to existing geometry features. This categorization is the basis for the explicit reference

methodology, the main purpose is to reduce the constraints linked to geometry which allows a

more efficient managing of functional references for complex parts [20]. Moreover, the design

problem and hence the parametrization can be classified in three classes according to their

complexity, see Figure 7. The complexity is defined by what is known and unknown regarding

the design problem. Class 1 is defined by a design problem where the general structure for the

design object is unknown. Class 2 design problems have an unknown scheme (layout and

composition) but a known general structure for the design object. Class 3 is defined by having

both general structure and scheme for the design object known [21].

Figure 7: Classes of problems dividing the design process compared to the classic design approach adapted from

[21].

The three classes match and cover the design stages conceptual, embodiment, and detail

design. Further categorization of the three classes can be made, Class 1 being configurator

design, the primary task is to establish a layout for how the pre-defined parts in the product

base should be configured. Class 2 resembles topology design, decisions are made regarding

the parts arrangement, this is based on the design problem and its generic structure. Class 3 is

parametric design, attributes and characteristics are completed. Problems can however contain

elements of all classes, a Class 1 problem can for example contain both Class 2 and 3.

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Furthermore, parametric design and Class 3 can thus appear in problems of the character

Class 1 and 2. [21]

2.8 High level CAD modelling

Modern CAD software give the user the possibility to create flexible geometric models through

its integrated tools. Nevertheless, to utilize these tools to their full potential, general techniques

applicable regardless of software are needed. These techniques should be structured and

categorized to further ease design automation, since they represent:

− A foundation for discussions and outlines of activities regarding design automation

geometry.

− A reference that can be used to seek useful advice from whilst exploring solutions.

− A guiding plan to find the essential level for the geometric design automation in an

accessible way.

KBE tools can be utilized to achieve design automation, through the usage of such tool, rules

relations and facts can be stored to capture knowledge in an effective way. High level CAD

templates (HLCts) can be stored and utilized through a data base with the use of KBE. Such

templates (HLCt) are CAD models defined with a higher abstraction level, defined through a

few or various objects allowing the model to be instantiated in a product design and assume

form defined by the product. HLCts can be stored in libraries and therefore advantageously

used in a KBE, allowing engineers and designers to create the outline product and then

implement HLCts in the product for which they can change the parameters to obtain the wanted

design. Furthermore, HLCts can be used by a large target group and don’t require a specialist

to be used, these models are created in the CAD software and can then be utilized by others.

[19]

Two categories of achieving geometry transformation will be presented in this section, these

two being morphological and topological transformation. Changes due to morphological

transformation occurs within already existing objects, the geometry of the object gets new input

which enables change. The object must be re-evaluated to assume the change of the

morphological transformation. The different levels of the morphological transformation will be

presented, see Figure 8. The model complexity and the knowledge-content present in the model

is increases for each level in the pyramid. Geometry change of a HLCt requires a morphological

change while instantiating one requires a topological transformation. Topological changes

imply that three types of events are possible, which are addition, subtraction, or replacement of

objects. A disadvantage of morphological transformation in an automation process is that the

number of objects is fixed, but this does not apply to topological transformation. To further

describe the topological process, three words will be used, template, constraint, and context.

Template corresponds to the object in which the new instance is to be placed; constraint are the

boundaries that exist in the templates that the instantiations follow; context are the geometric

boundaries that exist and to which the constraint refers. The levels of the topological

transformation can be seen in Figure 9. [19]

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Figure 8: Morphological transformation pyramid displaying the different stages. Asset: Amadori [19].

The four stages of a morphological transformation will be presented, they are as follows: [19]

1. Fixed Objects are constant in their geometry and do not change appearance. A fixed

object cannot be controlled with parameters and assume a new form, such object has

therefore no added value regarding morphological transformation.

2. Parametrization allows an object to vary in the dimensions that are parameterized, as

opposed to a fixed object. A purely parameterized model does not allow for relations

between parameters or geometric objects, it is therefore better suited for simpler models

with a low complex geometry.

3. Equation Based Relations described by relationships in the form of mathematical

expressions between parameters and or geometric objects. This can also lead to a

reduction in the number of parameters as several expressions can be formulated by the

same parameter or combination of several.

4. Script Based Relations imply that the relationship between parameters and or geometric

objects are created with a script expressed in a programming language supported by the

CAD system. Both Script Based Relations and Equation Based Relations are based on

rules, the difference is that Script Based Relations are expressed through logical

reasoning instead of mathematical expressions, which can make it more user-friendly.

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Figure 9: Topological transformation pyramid displaying the different stages. Asset: Amadori [19].

The four stages of a topological transformation will be presented, they are as follows: [19]

1. Manual Instantiation is realized through manual work by means of copy and paste

functions of various objects into the template, the object that is pasted is not context-

dependent upon creation.

2. Automatic Instantiation is enabled through defining only the template, this allows

instantiation to slavishly be place into the template. The number of instantiations is

created by a parameter that controls the number of instantiations to be instantiated in

the template. Due to missing definitions constraints, the instantiations are not context

dependent.

3. Generic Manual Instantiation requires a defined template and constraint manual to be

feasible and to create context dependency for instantiated instances. These two define

the template and its geometric boundaries for that instances. This allows the instances

to be instantiated manually in the template and assume the desired shape.

4. Generic Automatic Instantiation creates instances that are context dependent and

parametrically variable. This is made possible by pre-determined functions that can

automatically generate or remove instantiations from the template, depending on input

from the user.

2.9 Design automation

The design process often contains numerous activities and follows a similar outline, starting

with a search for solutions, identified solutions are compared and through a step-by-step

process, the solution that best meets the requirements is ultimately selected. However, changes

may occur even though a product has been launched on the market, this could be updates or

development on older previously used products. Implementing all changes again for a similar

design can be costly in terms of time. Introducing automation to as many parts of the repetitive

process as possible can reduce development time and cost through faster market launches. The

reduction of repetitive and tedious work for designers can and instead give them the opportunity

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to spend time on other value creation and which requires creativity. [19]

The word Design automation is broad and includes many different categories, as long as it can

be classified as a design and it can be automated, the word design automation can be used.

Among others, this applies to areas such as mechatronics systems, geometry, electric circuits,

or material [5]. This thesis will treat the area of geometry-based design automation (GDA).

Design automation can be defined as a system that can perform design tasks in an automatically

manner, inputs from the user can be loaded into a model that changes the output. In a simple

way, this could be done with a calculation program that receives inputs from the user and

through a calculation model produces design outputs. Amadori in [19] presents a perception of

GDA, the process must include a CAD model in the development loop for the product. The

process for GDA can be seen in Figure 10 and further described as follows:

− The user enters the required design inputs.

− Pre-determined strategies process the inputs.

− The inference engine stores the instructions and provide it to necessary HLCts which

are stored in a database.

− The product geometry model is generated by using HLCTs.

− The completed geometry model is then used to perform product analyzes.

Figure 10: Example of geometry-based Design Automation process adapted from [19].

The data that is analyzed out of the process does not bind to a type of output data but can be a

variety of options, from high fidelity FE calculations to calculations from a formula book. [19]

Skarka in [17] presents a similar description of design automation where generative models

differ from geometric models, which is the usual output from an advanced CAD system. The

geometric models are designed with fixed dimensions and without the possibility of change,

while the generative model is a representation of the model even in the event of a change in

geometry. Similar to the GDA process in Figure 10 expressed by Amadori, Skarka describes

that the generative model is based on a geometric model that can assume different forms,

controlled by parameters, rules and formulas. The model takes its shape depending on

requirements used as input to the model. Two approaches are possible to create a generative

model, where one uses the CAD system's knowledge tools while the other focuses on object-

oriented programming. The object-oriented programming approach creates more sophisticated

generative models but is more time consuming while the other approach is less time consuming

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and gives the developer the opportunity to build and test the models in the CAD software. The

generative model automates the construction of a geometric model and enables designers to

focus on creative work. [17]

2.10 Software testing and quality assurance

Quality has been sought by man in every artifact produced, which has its origin long before

software systems. With the explosion of the internet, a revolution involving quality has been

spreading, introducing global competition, outsourcing, off-shoring and foremost customers

with increased expectations and concept of quality. Traditional quality methods were based on

identifying defective products in the final stage of the product development, these methods have

been replaced by new approaches where quality is instead included in every step in the

development process. [22]

An important activity in generating and ensuring quality assurance is testing. Testing helps to

increase quality by repeating the cycle test – find defects – fix during development. Moreover,

testing is a quality verification to see how well the product works before it is released to the

customer. The division of software quality can generally be divided into two broad categories,

namely static analysis, and dynamic analysis, described as follows: [22]

− Static Analysis, different types of documents, namely requirement document, design

documents, software models and source code are analyzed and examined. This includes,

among other things, methods such as code review, algorithm analysis, and inspection.

Static analysis implies not executing the program or code, but rather examination of its

behavior in possible situations which could occur during execution.

− Dynamic Analysis, to expose and identify failures in the program, the program is

executed in the dynamic analysis. In addition, the behavior and performance of the

program is examined during run time. Input values inserted into the program can be

selected at random or after careful decision. Conclusions of the quality can be drawn

from the behavioral properties of the program.

The probability that faults are not detected is likely, no matter how many test – find faults – fix

cycles are run, faults that later will end up and be detected by the end user. A quantitative

measure for evaluating quality regarding software is reliability. The definition of software

reliability is described by Kshirasagar et al. in [22] as:

“The probability of failure-free operation of a software system for a specified time in a specified

environment”

Inputs that are fed into the system influence the probability of failure as these can create faults

surfaced by the end user. Random testing of inputs can be used to estimate software reliability,

as the definition of system reliability described by "specific environment", it is important that

the inputs used in testing reflect those that will be used in the future by the end user. [22]

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3 Method

In this chapter, the methods and tools used in the thesis are described. Including problem

definition/analysis, criteria specification, concept generation, evaluation and selection,

realization, and analysis, see Figure 11. The general method applied for this thesis much follows

a proposed method by Johannesson et al. in [5]. However, changes and adjustments have been

made to tailor the method for this thesis project.

Figure 11: General outline of the main activities performed in the method for this thesis.

The problem-solving process for this thesis can be described as divergent since more than one

solution could achieve a satisfactory result. Design automation can be achieved in numerous

ways and through different means. The challenge lies in developing an automation process that

fit the needs of the company. This method was therefore chosen since it allowed this open-

ended question to be systematically solved. [5]

3.1 Problem analysis and definition

To obtain an understanding of the problem background, the current situation, and the obstacles

this project faces, the phase problem analysis and definition was performed in the beginning of

the project. Multiple methods were used to gather information and data.

3.1.1 Theoretical reference frame

A theoretical reference frame was formed in the beginning of the project, it was deemed

important that the basis of the thesis was grounded and linked to facts. The theoretical reference

frame was formed from gathering information about relevant topics to gain insights on recent

trends and established theory. Sources in the form of research articles, journals, books, and other

relevant literature was utilized. The sources used was carefully selected to increase the

reliability of the thesis. The areas covered by the theoretical reference frame were the problem-

solving process, methods for data collection, criteria specification, concept generation methods,

design automation and software quality.

3.1.2 Data gathering

The conduction of interviews was chosen as a method to gather data and information since it is

an intuitive way to gather data and still gain personal contact with the respondents, something

that can result in better understanding of the problem and in-depth data [11]. The sought-after

information was regarding the current need for CAD material, the old automation process, and

the automation process currently in use at the department for steam turbine design. The

interviewees were selected subjectively in an attempt to pick respondents that were thought to

contribute the most to the study. People from different departments and functions were selected

to get different perspectives and thoughts on the topic. The common denominator of the

interviewees was that all of them work with or have worked with diaphragms and/or design

automation in one way or another. A total of five interviews were conducted, the various

representatives interviewed was: Component Engineer, Technical sales support, Production

Engineer and Development professional within calculation.

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The specific approach for the interview method was semi-structured interviews since to goal of

the interview was not only to get quantified data but also to get an understanding of the

interviewees experience and thoughts. This approach was chosen since it allowed the

interviewees to express their experiences both quantitative and qualitative [13]. Five main

questions were prepared beforehand that were asked to all interviewees. The order of the

questions was predetermined, and follow-up questions were asked if more in-depth answers

were required. General questions were asked in the beginning of the interview to get to know

the interviewee, problem-specific questions were asked thereafter. Depending on the role of the

interviewee, role-specific questions were asked with the aim of obtaining as much relevant

information as possible of the interviewees experience.

The interviews were conducted through online video meetings by one person, the author, who

asked the questions and controlled the conversation. Video meeting was utilized since it was

considered the most appropriate way for all parties to participate due to the current situation

where most employees at Siemens Energy work from home. All interviews were recorded to

enable a thorough analysis of the data at a later stage, this also made it possible for the

interviewer to focus on the conversation by not taking notes. The gathered data was analyzed

through summarization within a day of the interview occasion to keep the memory of the

interview fresh. The whole interview was first listened through and written down literally. The

summary was performed by carefully reading through the entire interview and picking out what

was considered most important from each question. The answers from all interviews could then

be summarized under the different main questions, which created an image of all respondents'

answers for each question.

Apart from interviews as a method for gathering data, continuous discussions with Siemens

Energy were carried out. The information gained could support the gathered data from the

interviews. These two methods gave an understanding of the problem background, the current

situation, and the obstacles this project faces.

3.1.3 Cost analysis

To clarify the current extent of Siemens Energy’s production regarding drawings for

diaphragms, a cost analysis was performed. The purpose of the cost analysis was to identify the

current quantity of diaphragm drawings, the dimensions that those require, and the level of

complexity of the drawings. Furthermore, an understanding of the need for an automation

process and to what extent was also sought. To further illustrate on possible time saving,

measured time saving for the old automation process in Cadds5 and time estimation for manual

work was compared.

The definition of complexity within CAD is diverse, it can be defined as the amount of effort it

takes to design or manufacture something, a longer design process would imply a higher degree

of complexity. Furthermore, complexity can also be defined by the number of features in a

model or drawing, more features equal higher complexity. Both definitions of complexity were

applied in this analysis. [20]

In collaboration with the supervisor at Siemens Energy, an estimation was performed to

approximate the number of EBW diaphragms that on average are produced each year at the

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department of steam turbine design. The number of drawings per diaphragm is currently

constant. An estimate was necessary as the order volume can differ significantly between

different years. An analysis of each drawing was made where the number of dimensions, notes

and views were recorded, see Figure 12. This was done for a randomly selected standard

diaphragm; simpler calculations were performed to illustrate the current extent of diaphragm

drawings.

Figure 12: Example of the different drawing annotations that was considered in the drawing analysis.

Dimensions are measurements considering dimensional values and tolerances. Notes are

information placed on the drawing that is not expressed only in dimensional values. These can

be placed as pointers who refers to specific positions or areas with a longer text description

placed to the side of the drawing. View is the visible component or part of component displayed

on the drawing. Multiple views can be placed on a drawing. [23]

Gathered time data for the old automation process was analyzed to sort out the interesting

information regarding diaphragms. Together with the supervisor and two component engineers

from Siemens Energy, a time estimation was performed for manual work for the same drawings

as the time data for the automation concerned.

3.1.4 Process mapping of preceding steps

Process mapping was used as a visual aid to illustrate how the development process is structured

and laid out. The main parts of a process such as activities, Input, output and how these are

connected was displayed in a structured way [24]. The process mapping tool was utilized for

the purpose of visualizing and clarifying the preceding activities to the CAD automation. The

process mapping was performed by first deciding the level of detail for the mapping. It was

decided that an overall level would be used, it was deemed appropriate since it provided a

sufficient understanding of the preceding activities to the automation.

To map the process, meetings were held with the person responsible for the preceding activities

to the CAD automation. The person in question went through the process and described the

various activities in detail.

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3.2 Criteria specification

The method used for systematically identify, handle, and assess criteria for the project was to

set up a design specification. The method was chosen since it categorizes criteria in a structured

way of working. [6]

Before the design specification was created, main categories for criteria were identified. The

main categories were then used in the search for design specification criteria. Multiple sources

were used to identify criteria for the design specification, including data from interviews, cost

analysis, the company, and information from discussions with the company. Different sources

were utilized to get a broader span in the search for criteria, thus reducing the potential of

overlooking criteria [5]. The identified criteria were written down in simple statements and

validated if they were to be implemented.

The criteria to be implemented in the specification were then rewritten, specified, and classified

as demands or wishes depending on their considered importance before they were inserted into

the design specification. The wishes were weighted to demonstrate their significance, a scale of

one to five was used, with five representing the highest importance and one the lowest [5]. The

complete specification was then discussed with numerous employees at the company to get

several perspectives and to ensure that the same goal was shared.

3.3 Concept generation

Two methods were chosen for generating concepts, Information gathering and Analysis of

existing systems. Both methods analyze already existing solutions, an approach suitable for this

project since new ways of achieving design automation was not sought, but rather uses existing

solutions or combinations of several [6]. Siemens Energy have already made some progress

within design automation, these approaches were utilized to gain more knowledge. Existing

solutions at Siemens Energy as well as solutions from established theory and recent trends were

analyzed.

Analysis of existing systems was initially performed; the method was used as a tool to search

for solutions internally at the company. It was performed as the opening method to gain more

knowledge in the field and to avoid spending time at a later stage researching methods that

Siemens Energy already uses [6]. Two of Siemens Energy's automation processes were

analyzed. The two analyzes were performed differently since the two automation processes

exist in different CAD software and the possibilities of getting access and use the programs

differed. The automation process in Cadds5 was analyzed initially. The possibility for the author

to use the software for research purposes did not exist, meetings were therefore held with

employees who have been involved with the development and worked with the automation

process. The employee displaying the software demonstrated the automation process by going

through the different steps and describing how they worked, information was also given

regarding the underlying code and functions.

The CAD program NX was next to be analyzed, parts of the analysis were a mimic of the

previous performed. A meeting was held with an employee who is primarily responsible for the

CAD automation used at the department. The employee displaying the software presented the

automation process by going through the different steps describing how they worked. The focus

of the automation process walk-through was on the general methods used. With an overall

understanding of the process, the next step was to thoroughly analyze the automation process

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based on own experiences. The various components of the process were analyzed in detail.

Information gathering was used to search for external sources on how others have accomplished

CAD automation and how similar problems have been solved [6]. Initially, information was

sought on a broad front, but as the area of knowledge had been searched through, specific

research was performed in promising areas. Sources used to gather information about the

subject was articles, reports, and websites.

The information from analyzes of existing solutions and information gathering was applied to

the current problem to produce solution proposals. The solution proposals were developed

independently but were discussed with the supervisor at the company before the next step in

the problem-solving process was initiated. Various solution proposals adapted to Siemens

Energy's development process were produced.

3.4 Concept evaluation and selection

The method used to evaluate and select concept(s) was Kesselring concept scoring matrix. The

method was used to visualize the results for the different concepts against selected criteria in a

structured way. This method fit into the already chosen method approach since a design

specification with wishes and demands already was created. [5]

The criteria used in the weighting method were those that had been developed in the design

specification, since the weights of all wishes already were determined, these remained and was

utilized in the criteria matrix. One solution at a time was reviewed and estimated on how well

it fulfilled the different wishes. The scale used was one to five, where five corresponds to the

most possible fulfillment and one the least. When all concepts were weighted, each solution

and their score was compared with the other solutions to ensure that the estimate of their wish

fulfillment was reasonably set. The results of the weighting matrix were discussed with the

supervisor and employees at Siemens Energy with knowledge in the field. This was done to get

a unified view with the company and get their opinions on the decision matrix. The solutions

with the best results were chosen to proceed with.

3.5 Realization

The realization utilized the developed solution concept(s) to produce results, the results to be

produced included a general automation strategy as well as implemented example of this

strategy. The method used to realize the selected concept(s), which imply

developing/implementing a knowledge-based engineering system was to utilize the MOKA

methodology. The MOKA methodology covers the main life cycle phases included in a KBE

system and their development [16]. This method was chosen since it is applicable when

developing both parts and a complete KBE system. The included phases for this method were

Capture, Formalize and Package [17]. These were the basis for the realization approach.

3.5.1 Capture

The initial phase Capture collected and structured raw knowledge to be utilized in subsequent

phases [16]. The first activity was to decide for which components in the diaphragm the

realization should concern, and thus which knowledge should be captured. The diaphragm

components were analyzed individually and in groups, the gained knowledge became the basis

for decision. The decision was based upon two statements, the first one being that components

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were chosen based upon the logic structure between components in the diaphragms. Secondly,

components whose development and implementation into a KBE system were thought to fit in

the time-scope of the thesis were chosen. To gather knowledge about the selected components,

several activities were carried out. Information was gathered to gain awareness of possible

diaphragm variations. The analyzes investigated historical variants of diaphragms and more

specifically the chosen components of these diaphragms. Moreover, parameter data from the

parameter producing Excel program was examined and visualized, this was performed to

display the parameters and get an understanding of its extent. The findings regarding the

selected components were recorded to be utilized when implemented in the KBE system.

3.5.2 Formalize

The second phase Formalize enabled the development of product and process models by

presenting a structure of how the following phase should be executed [16] [25]. The Formalize

phase was initialized by defining the type of design problem to be formalized. The gathered

knowledge from the previous phase and the nature of the problem was used to classify the

design problem and its complexity. This was deemed necessary since it had a dependency with

the problem structure and the approach to achieve design automation created within this phase

[21].

The general structure describing the automatic generation of diaphragm manufacturing basis

utilized the data gathered from the previous phase. Apart from that, information was sought and

gathered from the software’s that Siemens Energy uses. The main obstacle to overcome was to

gain sufficient understanding of the software’s and how information could be transferred, and

thus allowing an efficient process. The CAD program NX, the Product Lifecycle Management

(PLM) program Teamcenter and preceding activities to the automation process such as Excel

was explored and analyzed with respect to automation. Likewise as presented in 2.9 by Skarka

and Amadori, a general flowchart structure and strategy of the automation process and how

information is transmitted between the different steps and what activities is included was

formed [17] [19] [26].

3.5.3 Package

In the third phase Package, the application was developed. The formalized knowledge was

converted into a platform-specific software tool with possibilities for KBE system automation

[25]. The initial work of the Package phase was CAD modelling and creation of HLCts to be

used to achieve automation [19]. The Explicit reference modeling method was used in the

creation of the models for the selected diaphragm components. This method was utilized since

it provides a direction of work to achieve best practice parametric CAD modelling [20]. One

component at a time was modelled and parametrized until a state of adequate completion was

reached. When all components had reached this level, the components were implemented in the

same system to model the relationship and dependency between each component to obtain the

characteristic of the complete system. Functions, rules, and model reactions was implemented

both on component and assembly level. Once the complete system worked as intended, each

component was finished on a detailed level.

The technical drawings connected to the parent HLCt components were initiated when both

component and assembly level for the parts had reached an adequate state of completion. One

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drawing at a time was modelled, the procedure was however similar for all drawings. The layout

of the drawing was decided initially, old drawings from Cadds5 was utilized as a benchmark

for how the new drawings should be visualized. The drawing was thereafter created through

defining the views and measurements to be implemented in the drawing. All views,

measurements, notes and their relative position on the drawings was parametrized and

implemented as knowledge in the drawing model, controlled through functions and rules. All

geometrical variation of the parent model was considered in the creation of the drawing.

3.6 Analysis

The analysis was performed as a concluding activity in the project to examine and assess the

developed results. The produced result was examined and analyzed from the perspective of

quality, possible time savings and the design specification.

To ensure that the modelled components and drawings complies to the quality measures of

Siemens Energy, minor static and dynamic analyzes were performed continuously during the

development. The components were initially modelled based on already existing drawings to

gain a baseline that was deemed quality assured. The static analysis consisted of code review

and inspection of the performed work. Moreover, less extensive dynamic analyzes were

performed in parallel with development, the code was executed and the behavior of the models

examined. [22]

A larger dynamic analysis was performed in the concluding stage of the project, acting as a final

quality validation. As input to the system, parameter files from existing diaphragms were

created and utilized. The parameter files were selected to reflect the diaphragms to be created

in the system, but with varying appearance to ensure the models capability to adapt to variation.

Since parameter data from already existing diaphragms were chosen, their drawings were used

to validate if the created models and drawings yielded the correct result. This gave the

developed KBE system and the models a quantitative measure on the software’s reliability. [22]

The dynamic analysis was performed in multiple test cycles. Corrections and fixes were

performed in-between cycles to correct the error and faults that were identified.

Once the quality verification on the software was completed, time studies was initiated. The

time studies measured the time for developing a new diaphragm configuration. This was carried

out to have a quantitative measure to estimate the improvement of the developed solution

regarding time. A procedure as similar as possible to the previous performed time studies

regarding diaphragm development by Siemens Energy was adopted. The start of the time

measurement referred to the part in the process where a parameter file was complete and ready

for implementation. The time measurement ended after the part and drawing was deemed

complete and a complementing list including component material and information was finished

in PLM. Implying the same time frame for measurements as for the old process. The time

studies included numerous time measurements on all components to create an average.

Comparisons between the measured average time for the developed automation process and the

time measurements from the old automation process was performed.

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4 Results

This chapter presents the results of the thesis, including the problem analysis and definition,

criteria specification, concept generation, evaluation and selection of concepts, realization of

the selected solution and analysis of the results, implying time and quality evaluation and

testing.

4.1 Problem analysis and definition

The problem analysis and definition were carried out to ground the project on a well-defined

current situation, future decisions could then be based on a stable foundation. The results from

the various procedures are presented in this chapter. These include the results of the interviews,

the cost analysis for the creation of drawings and process map of the preceding steps to the

CAD automation.

4.1.1 Data gathering

The gathered data mainly came from the conducted interviews, the five general questions used

for all participants during the interviews are presented below, these were as follows:

− Can you tell me about your role and tasks that you perform at Siemens Energy in your

daily work?

− Do you encounter diaphragms for steam turbines in your work tasks?

− What material in the form of drawings and models do you require in your work with

diaphragms?

− Did you get in touch with the previous automation process in Cadds5? If so, what did

you think was good and bad with it?

− What are your thoughts on a new automation process in NX, do you have any

requirements or wishes on such process?

The results from the five common questions and the respondents' answers will be presented in

text format following the chronological order of the questions presented above, the whole

outline of the interviews can be seen in Appendix A.

All selected interviewees encounter diaphragms in their work. One of the interviewees worked

with diaphragms daily while the others have tasks occasionally concerning diaphragms, usually

occurring when new diaphragms are developed.

The need for CAD material in the form of drawings and models varied between the different

functions, all interviewees mentioned that there was a need for drawings in their work with

diaphragms. The CAD drawing material has an important function for multiple interviewees,

these including manufacturing, technical sales support, and calculation. The production

engineer who has the most interaction with diaphragms expressed that there is a varying need

for CAD material depending on the type of diaphragm to be manufactured. A recently updated

machine park at Siemens Energy implies new manufacturing conditions. Previously manually

programmed manufacturing machines that were used to manufacture diaphragms now require

CAD models. The production engineer stated that the demand for CAD models exists for

medium-sized diaphragms, for small and large diaphragms are there still only a demand for

CAD drawings. However, the demand for drawings still applies to medium-sized diaphragms.

The diaphragm categorization was performed by the production engineer and is based on the

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diaphragm diameter measurement, small diaphragms < 1200mm, 1200mm < medium

diaphragms < 1700mm and large diaphragms > 1700mm. This can be summarized as: the

demand from production is that all sizes of diaphragms need drawings while medium-sized

diaphragms also require CAD models.

Several of the interviewees expressed that they at a present stage are not in need of diaphragm

models. Drawings are sufficient CAD material in their day-to-day work, but if a model were to

exist, it would be utilized. One of the interviewees who is working with steam turbine

calculations expressed wishes regarding a CAD model. It would facilitate the work if there was

a model or similar that described the steam duct in the diaphragm.

Two component engineers with experience of the old automation process in Cadds5 expressed

that the created drawings in the old process were too cluttered regarding the dimensioning, this

made them confusing and hard to interpret. They also believed that the old process had

weaknesses in the fact that drawings to an extent was not true in their geometry, but rather

templates where the values for the dimensions change. Another respondent expressed that

templates was a good solution, it entails less maintenance, something that was considered good

since the department does not have many employees who can maintain such process.

4.1.2 Cost analysis

The extent of work required to produce diaphragms at the department of steam turbine design

was mapped by analysis of existing drawings. This was then linked to previously measured

time reductions and newly performed estimations to create an understanding of the problem, its

size, and the possibility of improvement.

All types of drawings that are currently created for diaphragms were analyzed, this included

five drawings. The drawings that were analyzed regarded the following parts and manufacturing

basis: Inner guide vane strip, outer guide vane strip, guide vane, welding, and machining. The

full extent of the gathered data can be seen in Table 1. The estimated number of diaphragms

developed at the department was estimated to 20 diaphragms per year. This estimation was

performed by the supervisor and two component engineers at Siemens Energy based on

previous diaphragm order history.

The diaphragm drawings can be divided into two categories, component drawings and

manufacturing drawings. The Inner guide vane strip, outer guide vane strip and guide vane are

component drawings, containing information regarding the components' appearance and

tolerance requirement. The manufacturing drawings consist of welding and machining, these

contain information defining the manufacturing method and where and how it should be

performed, tolerances are also stated.

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Table 1: Drawing analysis of diaphragm.

Drawing analysis, diaphragms

Drawing Dimensions Notes Views

Welding 35 30 6

Machining 164 40 15

Inner guide vane strip 27 13 3

Outer guide vane strip 28 13 4

Guide vane 22 5 7

Per diaphragm 276 101 35

20 diaphragms/year 5520 2020 700

By comparing the different drawings from Table 1, it can be seen that the complexity between

the drawings differs. The drawing with the most dimensions, notes and views is the machining

drawing, thus being the most complex. The manufacturing drawing makes up the largest part

in all three categories and measures approximately up to half. The four remaining drawings

have more similarities but with a certain spread. The number of dimensions per diaphragm was

measured to 276, 101 notes and 35 views. With an estimate of 20 diaphragms in one year, this

would imply 5520 dimensions, 2020 notes and 700 views.

The estimated 20 produced EBW diaphragms per year concerns the service division at Siemens

Energy. It can however be compared to the number of diaphragms produced when production

of new steam turbine existed in Finspång. An estimated 100 diaphragms were produced yearly

at the time of new production. The number of diaphragms produced yearly at present time

compared to then is a reduction of 80%.

Time measurements have been performed for the automation in Cadds5, this was done when

production of new diaphragms existed in Finspång and the annual production of diaphragms

was 100 units. The measured times regard standardized diaphragms without unique features,

which otherwise would increase the time required. Next to the collected data are time estimates

for the same work but performed manually, see Table 2. The time for manual work was

estimated by two component engineers and the supervisor at Siemens Energy. When the

automation process in Cadds5 have been used at the service department in recent years, the time

reduction has been estimated to be 30% compared to manual work. This since the diaphragms

that have been developed at the service division the recent years have been older variants not

following the standard.

Table 2:Time measurements and estimations regarding development for different diaphragm components.

Turbine step

Component HP [min]

HP (manual work) [min]

LP/IP [min]

LP/IP (manual work) [min]

Outer/inner guide vane strip 60 144 120 180

Guide vane 30 72 60 120

Welding 180 432 420 720

Machining 300 720 720 1200

Sum, 570 1368 1320 2220

Time reduction 58,3% 40,5%

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The turbine steps are labeled with high pressure (HP), low pressure (LP) and intermediate

pressure (IP) depending on the type of turbine and its working condition. The times are lower

for HP since they are more standardized compared to LP and IP, those two are similar. More

standardization benefits the automation process since less manual work is required. Hence the

time reduction is higher for HP compared to LP and IP.

Comparing Table 1 and Table 2, it can be seen that the number of measurements on a drawing

corresponds to the development time, more measurements imply longer time. For diaphragm

drawings, the two definitions for complexity as defined earlier are aligned. With a similar time

reduction or slightly less than 58% and 40% as displayed in Table 2, time could be reduced with

7-10 hours per diaphragm for the automation process to be developed, however depending on

the type of step in the diaphragm.

4.1.3 Process map

Activities positioned prior to the CAD automation are pre-established by Siemens Energy.

Through process mapping of the preceding activities, the process could be visualized and

clarified, see Figure 13. The preceding activities are Calculation, Data management, Turbine

layout and Exported parameters. The various activities in the process map will be presented and

described generally. Each preceding activity has a complex background and will therefore not

be described in detail. The activities prior to the CAD automation are necessary for the process

but not covered in the development part of this project.

Figure 13:Process map of the preceding activities to the CAD automation activity.

The first activity in the process is calculation, the calculations are performed in a self-developed

program by Siemens Energy called Axial. In the program, the user enters process data regarding

the entire steam turbine, this implies among other things, the existing appearance of the turbine,

power input. Based on the input data, Axial calculates the new appearance of the entire steam

turbine and its components. All data for the turbine is exported to a text document containing

data regarding performance, appearance, and parameter values for components in the turbine.

Activity two in the process is labeled as data management. The process map visualizes one

Excel file for this activity, there are usually multiple Excel files required for this activity, but

for simplicity, one is visualized and mentioned in the text. The purpose of the Excel file is to

give the user parameter values for the requested part. This is made possible by the Excel file

loading all the necessary data for the specific part/subsystem from the output of the calculation

document and turbine layout. There is a unique Excel xml file for each part/subsystem

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manufactured in the turbine, where the diaphragm is classified as such a subsystem. Through a

guided user interface (GUI), the user can choose for all, or a specific part of the subsystem to

sort and export parameter outputs.

The activity between calculation and data management can be named activity one and a half.

The data from Axial calculation is not sufficient for Data management to produce all

parameters, therefore is Turbine layout needed. Turbine layout draws the appearance of the

entire turbine, dimensions from this drawing complement the data from Axial calculation and

makes the input in Data management complete. This goal is that this activity is to be phased out

and eliminated from the process, it still exists and is therefore stated.

Activity three and the last step before the CAD automation is a text document created by Data

management. In the text document, the parameter names and their values are specified. This

text document enables the start of the automation process, the parameters can be used to specify

the shape of models and drawings in NX.

4.2 Criteria specification

The problem analysis and definition gave a visualization of the problem background and

clarified the current situation. The gathered data and information were the basis for the creation

of the design specification, whose task was to define what requirements and wishes the CAD

automation must and should strive to accomplish. The performed design specification and a

description is presented below.

The main categories used to search for criteria for the design specification were the following:

Drawings and models in general, Drawings and models small diaphragms, Drawings and

models medium-sized diaphragms, Drawings and models large diaphragms, Implementation

and use and Quality. These and the underlying criteria can be seen in Table 3.

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Table 3:Design specification for the diaphragm design automation process in NX.

Siemens Energy

Design specification for diaphragm design automation process in NX

Issued on: 2021-02-04

Criteria number

D W

Requirements Wish weight

Drawings and models: General

1 W True to geometry drawings and models 5

Drawings and models: Small diaphragms, diameter < 1200 [mm]

2 D Drawings for all parts and levels x

3 W Models for all parts and levels 4

Drawings and models: Medium diaphragms, 1200 < diameter < 1700 [mm]

4 D Drawings for all parts and levels x

5 D Models for all parts and levels x

Drawings and models: Big diaphragms, diameter > 1700 [mm]

6 D Drawings for all parts and levels x

7 W Models for all parts and levels 4

Implementation and use

8 D Fit and be compatible with existing development process x

9 W Decrease diaphragm development time with 30% 3

10 D Decrease repetitive design tasks of the user x

11 W Intuitive and user friendly 2

12 W Known technology by the company 4

Quality

13 D Quality assured x

Revision: 2 2021-02-10

Criteria 1: True to geometry drawings and models, can be considered as self-evident. But since

this has not been the case in one of the previous automation processes, it has been implemented

as a wish with high importance. The wish emerged during several interviews and conversations

with the company.

Criteria 2, 4, 6: Drawings for all parts and levels, the CAD automation process must be able to

produce drawings for all parts and levels. These requirements are the same regardless of

diaphragm size. The criteria is considered demand for several reasons; the production requires

drawings during production and several of the interviewees expressed a need for drawings in

their work.

Criteria 3, 7: Models for all parts and levels, the CAD automation must be able to produce

models for all parts and levels. At present, there is no requirement for models regarding small

and large diaphragms. Several of the interviewees expressed wishes for models for all

diaphragms, the weight is therefore set as a four.

Criteria 5: Models for all parts and levels, the CAD automation must be able to produce models

for all parts and levels. This is considered a requirement since production requires models to

manufacture medium-sized diaphragms.

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Criteria 8: Fit and be compatible with existing development process, a demand expressed by

Siemens Energy. The automation process must fit into their existing development process,

otherwise this work is redundant and cannot be utilized.

Criteria 9: Decrease development time by 30%, wish and benchmark for the project set by

Siemens Energy. The weight three is given since it is not deemed of utmost importance to

achieve this wish.

Criteria 10: Decrease repetitive design tasks for the user, demand set by Siemens Energy. The

requirement is based on the purpose of the entire CAD automation process, to reduce repetitive

design tasks.

Criteria 11: Intuitive and user friendly, wish that have emerged from conversations with

employees at the company. This will be pursued if possible but not deemed as the most

important, hence it has gained weight two.

Criteria 12: Known technology by the company, the steam turbine design department has

employees who will continue working with the CAD automation process after this project is

finished. Siemens Energy wants to pursue this work with the knowledge already existing at the

department. However, this criteria should not prevent solution alternatives that better fulfills

the design specification, hence it is set as a wish but with weight four.

Criteria 13: Quality assured, demand set by Siemens Energy which implies that the developed

solution must deliver a quality-assured result. Considered a requirement based upon its

importance.

Most of the criteria identified for the design specification are described in a qualitative nature,

however, this does not make them fully qualitative. Most of them can be verified in a

quantitative manner [6]. An example of this is the description for criteria one, which is solely

described in text. The requirement can be quantified by the simple question: Is the model true

in its geometry or not? This example can be applied to several of the criteria. In addition to

these, there are qualitative and quantitative criteria.

4.3 Concept generation

Concept generation was performed using two methods to identify and generate concepts. The

two methods used were Information gathering and Analysis of existing systems. The generated

solutions and a description will be presented. The solutions presented from the analysis of

existing systems are more detailed than the others, this is because the access to information and

the opportunity for the author to explore the processes on their own.

4.3.1 Analysis of existing system – Cadds5

The CAD tool Cadds5 has been used by Siemens Energy in Finspång since the beginning of

the 90’s. Cadds5 has only been used as a tool for creating 2D material at Siemens Energy. The

automation process in Cadds5 was developed in the end of the 90's with the aim of being able

to automate CAD drawings. This process was applied to diaphragms for steam turbines as these

were considered to be time inefficient since they involved time consuming and repetitive work.

The automation process requires input and guidance from the user to an extent, see Figure 14.

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The idea of this automation process is that already created templates are updated with new

dimensions in the drawing. The code in Cadds5 pick and assign predetermined parameters to

predetermined dimensions. When the drawing templates are updated, the dimensions in the

drawing are updated to the value of that specific parameter. Depending on the appearance of

the diaphragm, different templates can be selected to assure that correct dimensions are included

in the drawing.

Figure 14: General process map of the CAD automation process in Cadds5.

The process is initiated when steam turbine calculations are performed in the program Axial.

For a detailed description of Axial, see section 4.1.3. Axial calculates information regarding the

steam turbine, including dimensions and parameter values that describe the appearance of the

turbine. The turbine and mainly the steam duct are visualized in the Turbine layout activity.

This creates an overall drawing of the turbine appearance but describes the steam duct in a

detailed way.

All information regarding the turbine is available through Axial and the Turbine layout, the

following step collects all information so Cadds5 can utilize it. A macro named Umbrella is

executed in Cadds5, the macro opens a formatted Excel document where all required

information is to be implemented, this document will be referred to as Parameters. The required

data from Axial is automatically implemented through another macro existing in Parameters.

Information from Turbine layout must be manually measured in the drawing and filled in by

hand in Parameters. When all data is implemented, Parameters is complete. The diaphragm part

for which the drawing is to be generated is selected. A macro in Cadds5 is executed that retrieves

the implemented data from Parameters and applies it to a template drawing. The measures in

the template are updated, but since it is a template, the geometry appearance in the drawing

does not change. The created drawing in Cadds5 needs modification to be completed. One view

in the drawings is often true to geometry to visualize the true appearance of the component, this

must be manually inserted. The drawing is then completed, the approach is described in general

but is similar for all parts in the diaphragm.

4.3.2 Analysis of existing system – NX

Siemens Energy has since 2015 implemented the modern CAD program NX at the company.

Previous attempts to create an automation processes in NX have been carried out at the steam

turbine department, resulting in both completed and unfinished projects. EBW diaphragms that

this project examines is an example of a part that has not been finalized in NX. The general

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approach used to achieve automation at the department has been to utilize Knowledge Fusion

(KF) in NX. KF is an Application Programming Interface (API) directly integrated in NX. It

can be seen as a KBE tool, knowledge is integrated mainly through rules and expressions, code

can also be integrated to increase depth and customization possibilities [27]. The current process

utilizes KF rules to achieve morphological transformation, the approach used is both equation

and script based. A knowledge base is built in NX for the desired geometry, this enables other

users to utilize the stored knowledge in the design process of diaphragms [15]. The current

solution utilizes a parametric model that is built with rules that governs its function. Depending

on the parameter input, the model can assume different shapes, the process for CAD automation

is visualized in a general manner in Figure 15.

Figure 15: General process map of the CAD automation process in NX.

The four initial activities, including Calculation, Data management, Turbine layout and

Exported parameters will be described briefly, for a full description see section 4.1.3.

Axial calculates information regarding the steam turbine, among other things dimensions and

parameter values that describe the appearance of the turbine. The turbine and mainly the steam

duct is visualized in the Turbine layout activity. This creates an overall drawing of the turbine

appearance but with detailed description of the steam duct. The main input for Data

management comes from Axial calculations, some input is required from Turbine layout. In

Data management, all data is sorted and structured, the user can through Data management

choose for which part, parameters are to be exported. These parameters are exported as a text

file.

Design rules is the first activity in the CAD automation process that affects NX, located in the

first position inside the dashed square in Figure 15. Design rules are rules shaped to control and

delimit the CAD model, rules contain and are expressed using the model parameters. The design

rules are formulated as equations or scripts. The text document with the parameters is read into

NX and saved as parameters. The parameters are applied to the rules before the next step is

initiated.

The following activity is Parametric CAD model, the parametric CAD model is prebuilt and

utilized in the automation process. The model dimensions are parametrized, allowing the model

to change shape depending in the parameter inputs. In the CAD automation process, the model

is updated with the new parameter values, information, and rules from the design rules. The

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model is updated and assumes the shape according to the parameters. The model is completed

but will be used as a template for the drawing in forthcoming activity.

The next activity is drawing rules, similar to rules for the model’s design, the drawing needs

rules that control and delimit how the drawing looks and how dimensions and views should act.

The drawing created in the last activity is linked to the model, when the drawing is updated, it

takes the form of the parametric model.

Between some of the activities in the CAD automation process in NX, manual work needs to

be performed, for example importing parameters.

4.3.3 Information gathering – NX programming

The CAD tool NX supports various types of object-oriented programming within the software,

these can enable and give customizable knowledge driven automation capabilities. Developers

can use these to push the product development process forward and reduce development time.

Several of the NX programming tools use a common application programming interface (API)

called “One common framework”, enabling the developer to choose the programming language

of their liking. The language-neutral platforms support common programming languages like

Java, C, C++, and .NET languages such as Visual Basic or C#. The common APIs for NX

programming are NX Open, GRIP, Simple NX Application Programming (SNAP) and

Journaling, also included is the already mentioned Knowledge Fusion, see Figure 16. [27]

Figure 16: One common framework APIs supported by NX, adapted from [27].

Regardless of API, all the mentioned can be described as KBE tools which enables knowledge

exchange through the database between different users. All the mentioned APIs offer most of

what is expected of a programming language, and through a large library in NX, the user can

call for actions that enable the use of NX's traditional manual CAD tools and commands. Three

of the mentioned APIs above, being NX Open, GRIP and SNAP can be seen as programs

operating outside of NX. The APIs vary in complexity, both NX Open and GRIP are powerful

and well developed with breadth and vast possibilities, which also entails higher complexity.

SNAP is developed to be more accessible and user-friendly, lower complexity but less powerful.

Journaling is another tool existing in NX for creating shorter and less complex scripts, libraries

of both NX Open and SNAP can however be utilized within the journaling environment.

Journaling has the capability to record modelling sessions which can be saved, edited, and

replayed. Journaling also enables the user to pick a common programming language to record

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their actions as a recorded journal. [27]

Lowe et al. describes that the introduction of object-oriented programming on an industrial

turbine manufacturing company provided many benefits. Among other things, gave obvious

advantages in reduced development time. With a reduced development time, vital time could

instead be invested in increasing the number of design iterations in their development process.

The entire development process for a component could be built using code, from the creation

of a model to finite element calculations. The inputs needed to create the components were

points from calculations located earlier in the development process [28]. Similarly does Lobov

et al. present ways to utilize NX Open API to create a simple model, manipulate it and perform

finite element calculations. The simple approach presented illustrates how such approach can

be elaborated on, an extended process to create complicated models can be implemented within

the development process and utilized by designers [29].

4.3.4 Information gathering – Program from external contractor

Potential solutions were sought outside the area of NX during the information gathering.

Companies specializing in automation offer automation programs that via an API can

communicate with CAD software’s and be controlled by the automation program. One such

company that the author had contact with was Xperdi. The program that Xperdi offers enables

automatic repetitive tasks, from simple to complex models. To program has the possibility,

among other, to automate both drawings and models, which fit the needs for this project. [30]

4.3.5 Solution concepts

All developed solutions must comply with the requirements developed in the design

specification presented in section 4.2. Solutions not accomplishing these requirements will not

be presented since they were not considered good enough. The requirement Fit and be

compatible with existing development process embodied all solutions and gave them a similar

look, thus necessary to fit into the current development process. The search for solutions could

therefore exclude how the general process should be designed and instead seek means on how

this could be achieved, see Figure 17. The model parameters must be processed, and rules

controlling the model and the drawing created, the previous chapter displayed that this can be

realized by different approaches, programs, and APIs.

Figure 17: Process map of CAD automation process showing where solution alternatives in the form of a program

or API can be implemented.

Solution 1, NX KF – This corresponds to the current solution that is being developed at the

department. The procedure follows the process described in section 4.3.2. The API KF is used

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in NX to build a knowledge base for each model, controlling the appearance of both model and

drawing. The focus in KF is to utilize the possible methods, implying rules, functions, and code.

Solution 2, NX Open or GRIP – This solution uses one of the API's NX Open or GRIP, as these

two are most similar in terms of complexity and format, both have been placed under the same

solution. The solution would imply that a knowledge base is built up with code and that that

code controls the appearance of both model and drawing.

Solution 3, NX SNAP – This solution uses the API SNAP in NX, similar to the solution above,

code is used to create a knowledge base. SNAP is added as its own solution since the SNAP

does not possess the same complexity and advanced level as NX Open and Grip.

Solution 4, Program from contractor – This solution utilizes a program from an external

contractor to control and create models and drawings. The knowledge base is built up in the

external program, this in turn can be used to manipulate the parametric CAD model and the

drawing in NX.

4.4 Concept evaluation and selection

The generated concepts were evaluated and selected based on a criteria weight matrix, this

enabled a straightforward process for selecting solution or solutions for continued development,

see Table 4. The criteria and their associated weights used in the criteria weighting matrix

originated from the design specification and is described in detail in section 4.2.

Table 4: Criteria weight matrix of the generated concepts.

The result of the weighting displayed a relatively high score for all solutions, indicating that all

would be suitable suggestions. The concept with the best score based on the criteria was solution

one, which corresponds to utilizing NX built-in API KF. Succeeding was solution two and then

followed by solution three and four sharing the same points.

Solution one is considered to reduce the development time to a lesser extent as it may involve

more manual work compared to the other solution. The other three solutions are considered to

meet some of the other requirements better or as well as solution one, for example the first four

Criteria weight matrix

Criteria Solution alternative

ideal 1 2 3 4

w P t P t P t P t P t

True to geometry drawings/models 5 5 25 5 25 5 25 5 25 5 25

Models, all parts/levels, small diaph. 4 5 20 4 16 5 20 4 16 4 16

Models, all parts/levels, big diaph. 4 5 20 4 16 5 20 4 16 4 16

Decrease diaph. devel. time with 30% 3 5 15 3 9 5 15 5 15 5 15

Intuitive and user friendly 2 5 10 3 6 2 4 3 6 5 10

Known technology by the company 4 5 20 5 20 1 4 2 8 1 4

T=t 110 92 88 86 86

T/Tmax 1,00 0,84 0,80 0,78 0,78

Ranking - 1 2 3 3

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criteria. What lowers solution two, three and four is mostly the fact that all of them involves

technology that the company is not familiar with. Known technology should be consider when

analyzing drawing material and time studies and estimates, presented in section 4.1.2. The

volume of diaphragms produced yearly does not reach the same volume as when new

production of diaphragms existed in Finspång. At that time, more resources were directed to

the development of diaphragms, thus increasing the need of a complex and versatile automation

setup. Improvements that such system can imply in time reduction will not be as great for a

small production. The time for introducing an advanced CAD automation method for the

company was considered too large given the minor volume of CAD material that is produced

yearly.

The solutions chosen for further development was solutions one, which received the highest

points. The API Knowledge Fusion (KF) existing inside of NX will be utilized to develop a

KBE system allowing design automation of CAD models and drawings.

4.5 Realization

In the phase of realization, the generated and selected concept from previous phase was realized

and implemented at the company. For the creation of a knowledge base in NX by utilizing KF,

it was considered favorable to apply a method for the implementation. The results presented in

this chapter will follow the realization approach of the selected steps from the MOKA

methodology previously described, see section 3.5. The performed steps in the realization phase

from the MOKA methodology was Capture, Formalize and Package.

4.5.1 Capture

The initial step in the Capture phase was to decide which components would be used in the

realization and implementation. As mentioned briefly in section 1.2 and 4.1.2, the main

components in the diaphragms are the outer ring, outer guide vane strip, guide vane, inner guide

vane strip and inner ring, see Figure 18.

Figure 18: Diaphragm in two views, displaying a simplified view of the main components included.

The five components are included in all EBW diaphragm configurations, but the CAD material

required for their manufacturing differ. The three components, being outer guide vane strip,

guide vane and inner guide vane strip have their own manufacturing drawing as well as being

included in the welding and machining drawing for the assembled diaphragm. These

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components are manufactured separately, assembled, and machined before they are welded

together with the outer and inner ring. The inner and outer ring do not have their own drawings

but are instead bought as forging rings and shaped through machining after the whole

diaphragm has been welded together. This implies that the outer and inner ring only occur in

the assembly drawing for welding and machining. It was therefore decided that the Capture

phase and realization should include the three components outer guide vane strip, guide vane

and inner guide vane strip. This decision allowed the development of three unique models that

were connected in one assembly but still had separate drawings. These three components were

also considered a reasonable target in terms of the time frame for the project.

Multiple sources were utilized to gain further knowledge that was deemed important to achieve

CAD automation for selected components. Historical variants, parameter data from Excel, and

internal documents lay the basis for the captured knowledge. The captured knowledge for the

components outer guide vane strip, inner guide vane strip and guide vane will be presented to

familiarize the reader with possible geometrical variation which will be the basis for future

results. Abbreviations will be used to present the results of the captured knowledge, presented

both in text and figures. The commonly used abbreviations will be Axial Dimension (AD),

Radial Dimension (RD) and Guide Vane (GV).

The outline of the inner and outer guide vane strip mainly consists of straight edges with

perpendicular relations to one another, exception of this arises in the meridian profile which

only exists in the outer guide vane strip. The captured knowledge for the inner and outer guide

vane strip which mainly comes from Axial calculations and Data management can be seen in

Figure 19 and Figure 20.

Figure 19: Captured knowledge for the outer guide vane strip.

Most of the dimensions in the inner and outer guide vane strip can be labeled under Dimension

parameters, which refers to parameters that reads dimensional values and updates accordingly.

However, the dimensional parameters are occasionally expressed through a function depending

on other dimension parameters. The meridian profile in the outer guide vane strip is defined by

a spline which is created from 30 individual points. The shape of the meridian profile differs

depending on the setting of the diaphragm and can vary between a curved outline as in Figure

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19, or be completely straight. Moreover, most of the ADs in the inner and outer guide vane strip

measure between an edge of the outline profile and the global zero in x-direction, displayed as

a red line for the inner and outer guide vane.

Figure 20: Captured knowledge for the inner guide vane strip.

Visualized in both Figure 19 and Figure 20 is the guide vane hole profile which represents the

cutout hole of the current guide vane profile. The guide vanes are assembled with the inner and

outer guide vane strip through these holes. Similar as many of the ADs, the trailing edge of the

guide vane both for cutouts and profile are coincident with the global zero in x-direction.

The captured knowledge regarding the guide vane has its origin in the guide vane but is

connected to the inner and outer guide vane strip since both have holes mimicking the profile

appearance of the current guide vane. The captured knowledge concerning the guide vane is

dimensional parameters of varying type, AD, RD, angles as well as manufacturing information

is included to describe the geometry and its variation, see Figure 21.

Figure 21: Captured knowledge for the guide vane.

Knowledge represented in the guide vane but shared between the three parts are the GV profile,

GV profile scale and the number of GVs. The GV profile can alternate between five different

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guide vane profiles which is decided by computational fluid dynamics calculations in Axial, the

names of the profiles are P111, P13, P17, P21 and P25. The number of guide vanes and scale

of the guide vanes are decided through similar calculations. The guide vane size is calculated

and scaled according to a master profile of the current guide vane profile. Furthermore, the

guide vane hub can alternate its geometry by having a cutout or not. The guide vane including

a cutout and the captured manufacturing knowledge is visualized in Figure 21. The cutout on

the guide vane hub affects the guide vane hole profile on the inner guide vane strip since the

guide vane hub is assembled against the inner guide vane strip.

4.5.2 Formalize

The Formalize phase was initialized by defining the type of design problem to be formalized.

The captured knowledge from the previous phase and the nature of the problem served as a

baseline to classify the design problem and its complexity. The complexity and unknowns were

similar for all three components. The number of parts and their locations to one another are

predetermined by preceding activities in the process. Similarly, the topology of the components

is decided by preceding activities, this implied a problem having a known general structure and

scheme for the design object. The problem lay in building models that can assume geometric

variation, which is the basis for Class 3 and parametric design [21].

Based on the captured knowledge and the problem classification, a general structure and

strategy for the automation process was developed. How information is transmitted between

the different steps and what activities is included for the entire development of a new EBW

diaphragm was visualized, see Figure 22. The process includes already mentioned steps such

as Axial and Data management to visualize the process of the entire chain, in an attempt create

an understanding of how all activities are connected to the CAD automation process.

Figure 22: General structure and strategy of the automation process and how information is transmitted.

The development of a diaphragm is initiated when there is a need for a newly developed

diaphragm for rebuild or update expressed by a customer. A few preparing steps must be

performed before the design automation can be initiated, for a detailed description of the already

described activities Axial and Data management, see section 4.1.3. The process will be

described from a user's point of view, which in this case implies a component designer at

Siemens Energy. The development process is started and begins with a split in the process path.

Starting with the left split path and calculations in Axial. Design input is required and

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implemented by the user in Axial before the calculations can be started. The input data

implemented in Axial regards the entire steam turbine, this implies among other things the

existing appearance of the turbine, power input etc. Axial calculates information regarding the

steam turbine, among other things, dimensions and parameter values that describe the

appearance of the turbine. All data and information from Axial are transferred to the Excel based

program Data management where all data is sorted and structured, the user can through Data

management choose for which part, parameters are to be exported. These parameters are

exported as a text file with a specific formatting which is supported by NX and allows

implementation once activities on the right split path are ready.

The activities on both the right and left process path are necessary for the complete process and

can to some extent be executed in parallel. Continuing with the right split process path which

is commenced by the activity KBE model in PLM. The user locates the master KBE model for

the diaphragm in the PLM structure. The model contains the CAD models (parts and drawings)

and all knowledge implemented within the model. The master KBE model can be seen as a

template which stays unchanged and will not be edited. The user utilizes the clone tool

integrated in Teamcenter PLM and NX to create an exact but independent copy of the whole

structure of the KBE model, this includes everything contained in the KBE model such as parts,

drawings, rules, and functions implemented in KF etc. The new cloned KBE model is

independent of its parent and gets a specific name and ID linked to the diaphragm to be

developed. The following step is then initiated, where the user opens the new model in NX from

Teamcenter PLM. Once the model is opened in NX, exported parameters from Data

management in the form of a text file can be imported into the new model in NX.

The following step is where the selected concept of using KF as an API for creating a knowledge

base for design automation comes to use. The user updates the new model with the imported

parameters from Data management which applies to the rules, functions, and reactions of the

model. This implies an update cycle ending with design results. The user now serves as a last

quality assurance for the esthetic appearance of the models and checks whether the parts and

ultimately the drawings look accordingly. If the drawings are ok, the development process

moves on. If not, a manual adjustment is required. Such fix could imply moving a measure or

view that is intersecting or misplaced. The last step in the process, being File structure for

component in PLM, is excluded from this thesis and the CAD automation process. It is however

mentioned and displayed since it is a part of the development process and will be included in

the time analysis. When the part and drawing is complete in NX, the user adds the component

and sufficient information regarding e.g., manufacturing and material in the diaphragm and

steam turbine structure in PLM.

To further describe the structure of the KBE model and the exchange of information between

the KBE model implemented in NX and the imported parameters, the dashed activity NX from

Figure 22 will be described further. When developing the KBE model, there was no requirement

for creating an assembly at the stage of the development since the three models, being inner

and outer guide vane strip and guide vane, are independent and do not share component

drawings. However, an assembly was created since it structures all models in one assembly,

enables all models to share Interpart expressions and allows for further development where an

assembly will be required, see Figure 23.

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Figure 23: The structure and hierarchy of the KBE model as well as its connection to the imported parameters

inside NX.

The general structure of the model is depicted in Figure 23 and is explained as follows. All main

components and one called Interpart expressions are structured under the assembly with the

name Diaphragm Assembly. On component level lays, among others, Inner and Outer guide

vane strip as well as Guide vane which consists of both a part and a connected drawing. The

Outer and Inner ring is only represented as parts since these do not have a component drawing.

The last component in the assembly is Interpart expressions which is an empty part only serving

as storage for the current parameters. The parameters from Data management are imported

directly into Interpart expressions and stored within the part. All other components are modeled

and linking its parameters to the parameters stored in Interpart expressions. By utilizing this

solution, the parameters in Interpart expression can be updated once and the components

updates accordingly. Each part is only linking to part specific parameters to avoid unnecessary

time running an update cycle.

The top assembly holds two drawings, being welding and machining which includes all children

components. The drawings act as independent models with its own functions and parameters,

but with a link to the parent part. Any update to the part will transfer to the linked drawing. The

process for the user once the model is opened in NX is to activate the Interpart expression

component and import the new set of parameters. This will start the update cycle as all parts

connected to an updated parameter will start to update. The updated parts will change

appearance and in turn yield the drawings to update, the rules in the drawings will assure correct

measurements and placement of views and dimensions.

The concept of the model structure has been developed for all components and drawings.

However, the parts Inner and Outer ring as well as the assembly drawings has not been

developed in this project.

To further describe the logic behind the Interpart expression and the connection between the

selected components, the dashed activity Interpart expression from Figure 23 with its

connection to the components will be visualized and described further, see Figure 24. The

flowchart depicts the logic flow of the rules, functions, and reaction within each of the selected

components in KF.

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Figure 24: Flowchart displaying the logic behind the rules and functions that each component retrieves from the

Interpart expression.

All components get their input from the Interpart expression which is placed at the top of the

flowchart. The flowchart path then splits into the five components, since the components inner

and outer ring has not been included in the Capture phase, no further logic flowchart path has

been developed. The flowchart has been developed for the three components, being inner and

outer guide vane strip and guide vane, which have similar flow appearances. The flow of the

guide vane part will be dissected, same or similar approach can be applied for the two other

components.

The Interpart expression parameters are linked and connected to the guide vane part. The first

decision encountered in the flowchart is clockwise (CW) or counterclockwise (CCW) rotor

rotation in the turbine. This affects the whole setting of the guide vane and thus also the cutout

holes on the inner and outer guide vane strip. Depending on CW or CCW rotation, rotation

specific rules are applied to the part. The path after rotation specific rules is thereafter split in

three paths, dimension parameters, GV profile type and GV cutout. GV cutout is however only

applied in the guide vane and inner guide vane strip. The dimension parameters are part specific

parameters that ultimately control the appearance of the part. Parallel to dimension parameters

are two decision activities deciding which GV profile to be used and if the selected GV profile

should have a cutout in the geometry, as described in section 4.5.1. The three parallel activities

are completed and rejoined before the part is updated. The inner guide vane part has the same

logical flow while the outer guide vane part excludes the GV cutout.

4.5.3 Package

The Package phase developed the application, the formalized knowledge was converted into a

platform-specific software tool with possibilities for KBE design automation. The gathered

knowledge from the Capture phase in combination with the strategy presented in the Formalize

phase was utilized when developing the solution in the Package phase.

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The possible geometrical variation of the components and the logical flow of decision was

visualized and explained in previous sections. However, for the developed models to enable

such transformation, HLCts were created in KF similar as described by Amadori in [19]. To

further describe the complexity of the HLCts created, the HLCts will be described from the

perspective of the morphological and topological transformation triangle [19]. Since all models

contain similar complexity, no individual description describing the features of the components

will be presented.

Starting with morphological transformation, the developed HLCts utilizes all morphological

levels resulting in the models acquiring the highest level, being script-based transformation.

The script-based relations have been used throughout all components and utilized both on part

and drawing level. The rotation specific rules are one example where the script-based relations

have been utilized. Similarly, relations from all sub levels have been used throughout the

modelling process, being equation based, parameter based and fixed objects.

Unlike the morphological transformation, the level of topological transformation differs

between the components. The guide vane does not include any topological transformation but

supports morphological transformation. The inner and outer guide vane strip does however

include a form of topological transformation, similar to automatic instantiation expressed by

Amadori in [19]. The guide vane profile is instantiated into the parts of the inner and outer guide

vane strip to create the guide vane profile cutout in the parts. Only one guide vane profile hole

is instantiated into the parts, an equation-controlled pattern is utilized to create the remaining

cutouts on the parts. This was chosen since it was computationally efficient compared to

instantiating all cutout holes. The guide vane profile to be instantiated in the template is updated

through the imported parameters before it is instantiated, making the instantiation not context

dependent [19]. In the case of this project and CAD automation of diaphragms, no addition or

subtraction of instantiations was deemed necessary due to lack of parts in the diaphragm or

other reasons, as explained above. The instantiation does therefore only replace the previous

profile with the current, which is controlled through a script and an input parameter.

The developed CAD models manage the variation that has been presented in the realization

chapter. Since the full display of the geometric variation is not presentable, selected diaphragm

configurations displaying the geometry variation of the model will therefore be presented. The

selected diaphragm configuration varies in size, number of guide vanes, type of guide vanes,

rotational direction, component specific dimensions, and configurations, all affecting the

geometry of the components. The various geometry variations are presented in Figure 25,

Figure 26 and Figure 27.

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Figure 25: Example of a small diaphragm configuration displaying geometry variation.

The diaphragm presented in Figure 25 is of small character, implying small diametric

measurements and number of guide vanes. The rotational direction of the turbine is clockwise,

and the guide vane profile is P25, the most common profile used for steam turbines at Siemens

Energy. The meridian profile of the outer guide vane strip is formed by a third-degree spline

and the top face of the inner guide vane strip is conical. Geometrical variation compared to

Figure 25 can be seen in Figure 26 and Figure 27 which represents other types of diaphragm

configurations.

Figure 26: Example of a medium diaphragm configuration displaying geometry variation.

The diaphragm in Figure 26 is considered a medium sized diaphragm, having diametrical

measurements one third more than the diaphragm presented in Figure 25, something that also

affects the number of guide vanes. Furthermore, the geometry of the inner and outer guide vane

strip of the medium sized diaphragm differs compared to the small diaphragm. The inner guide

vane strip is completely flat on the top face as well as having different dimensions on the bottom

face. The outer guide vane strip displays a different geometry and variation of shape, but still

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having a third-degree spline as meridian profile. The steam direction of the medium diaphragm

is counterclockwise instead of clockwise, which mirrors the guide vane and its setting angle.

Moreover, the medium diaphragm includes another type of guide vane, a wider type called P21.

Figure 27: Example of a large diaphragm configuration displaying geometry variation.

Figure 27 depicts a large diaphragm configuration, being bigger and having more guide vanes

than both diaphragms presented. Apart from the size and the number of guide vanes, the

geometry consists of both new and already displayed shapes. The outer guide vane strip displays

a geometry variation differing from the small and medium sized diaphragms. The meridian

profile is conical, and the inlet (left side) is considerably larger than the outlet. Moreover, the

steam direction is clockwise resulting in a guide vane configuration similar to Figure 25. The

profiles of the guide vanes are P13 which have a similar look to profile P25. The inner guide

vane strip is conical and have similar appearance to the one used in the medium sized

diaphragm.

The CAD automation process goal was to create models and drawings of selected components.

The specification displayed a need for both models and drawings, and with the chosen strategy

for automation, CAD models for the development of drawings was essential. Furthermore,

technical drawings were an expressed need from multiple functions at the company. The

drawings play an important role in this project as they are used as a quantitative measure for

both quality and time reduction. The appearance of the drawings, function, and reliability is

therefore of the utmost importance for both this project and the company.

The creation and appearance of the drawings in NX were designed according to already existing

drawings at Siemens Energy. A standardized look was implemented in NX and the automation

process to make all drawings look similar in terms of view placement, dimensions, and

distances between objects. Examples of drawings created with the CAD automation for the

components outer guide vane strip, inner guide vane strip and guide vane are presented in Figure

28, Figure 29 and Figure 30, respectively. Multiple drawings for each component can be seen

in Appendix B. Sensitive company information have been censored on the drawings.

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Figure 28: Outer guide vane strip, technical drawing created by the CAD automation.

Figure 29: Inner guide vane strip, technical drawing created by the CAD automation.

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The drawings for the inner and outer guide vane strip are similar since their geometry is alike.

Both drawings consist of three views, one base view and two section views. The base view is

placed at the top right in both drawings and depicts the front view of the inner and outer guide

vane strip. Included in the base views is the section lines for the section views. The top left

section view displays the section of the profile and its outline geometry. Complementing this

view for the outer guide vane strip is a table including all points for forming the meridian

profile, both for curved and flat appearance. The drawing view at the bottom in the outer and

inner guide vane strip is the section view displaying the placement and configuration of the

guide vane cutout holes. Included is a smaller table with values for the view dimensions.

Furthermore, notes and tolerance table are included on the drawings.

Figure 30: Guide vane, technical drawing created by the CAD automation.

The technical drawing for the guide vane consists of six different views, see Figure 30. Two

base views are placed at the bottom left displaying the guide vane from two different angles.

Each base view has a detailed view magnifying the scale of a particular detail, labeled with a

letter. The section view in the top left originates from the most left base view, displaying the

geometry and outline of the guide vane and potential cut-out. The rightest view depicts the

manufacturing method and principle for the cut out. Notes and tolerance tables are included.

The presented drawings only showcase one configuration for each component. As mentioned

earlier, more drawings and hence the possible variation is presented in Appendix B. However,

clippings of interesting parts of the drawing will be presented since the CAD automations

possibility to adapt to variation is of interest. Two examples are depicted, one from the inner

guide vane strip and one from the outer guide vane strip, see Figure 31 and Figure 32.

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Figure 31: Inner guide vane strip, clippings of drawing displaying two outline configurations, flat to the left and

conical to the right.

The inner guide vane strip is represented by two different configurations, flat and conical inner

surface. The conical surface of the inner guide vane strip implies more dimensions and

requirements which increases the complexity of such a configuration. The knowledge and

drawing rules implemented in the model perceive the type of configuration through the

imported parameters and logic statements, the dimensions and notes are changed thereafter.

Figure 32: Outer guide vane strip, clippings of drawing displaying two guide vane cut-out configurations, CCW

rotation to the left and CW rotation to the right.

Two guide vane cut-out configurations differing in guide vane profile, turbine rotation and

model dimensions. The implemented drawing knowledge and rules perceive the type of rotation

direction currently acting and thereafter changes location on dimensions that otherwise would

interfere. Dimensions and objects low on the hierarchy are relocated in favor for objects that lie

higher in the hierarchy and that cannot be relocated. One such example is the geometrical

dimensioning and tolerancing frame which can easily be moved and have low hierarchy.

4.6 Analysis

The final activity performed in the project was analysis, the produced results were examined

and assessed from the perspective of quality and possible time savings. The quality verification

of the CAD automation will be presented initially, followed by the time measurements and

lastly a few words mentioning the specification.

To achieve a quality assured solution, the method dynamic analysis was utilized as a tool for

quality verification of the established CAD automation. The dynamic analysis was laid out in

multiple cycles where identified faults from previous cycle were corrected before the next cycle

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was initiated. The data included and reported in each test-cycle was: The order of the current

test-cycle, parts included in the test, how many tests performed in the current cycle, how many

of the performed test resulted in a successful result, how many of the performed test failed, and

lastly the success rate (reliability) defined as the number of successful tests divided by the

number of performed tests, expressed in percent, see Table 5.

All performed test-cycles included multiple tests. One test was defined by a new set of

parameter data (parameter file from an old diaphragm) that was imported into the three

components, namely, inner and outer guide vane strip and guide vane. A successful test implied

that all models have correct dimensions, and that all drawing views, data, and dimensions

correspond to the old baseline drawing. If any of these are violated or if the drawing esthetics

are unsatisfactory, the test was considered failed.

Table 5: Quality verification of the CAD automation and the performed test cycles.

Quality verification of automation process

Test cycle Part Nr of test

performed Successful

tests Failed tests

Success rate (Reliability)

1

Inner guide vane strip 3 0 3 0%

Outer guide vane strip 3 0 3 0%

Guide vane 3 0 3 0%

Total 9 0 9 0%

2

Inner guide vane strip 5 2 3 40%

Outer guide vane strip 5 3 2 60%

Guide vane 5 4 1 80%

Total 15 9 6 60%

3

Inner guide vane strip 5 5 0 100%

Outer guide vane strip 5 5 0 100%

Guide vane 5 4 1 80%

Total 15 14 1 93,3%

4

Inner guide vane strip 11 10 1 91%

Outer guide vane strip 11 11 0 100%

Guide vane 11 11 0 100%

Total 33 32 0 97%

In the initial test cycle, multiple errors were identified on each test performed, hence all tests

were considered failed. The identified errors were corrected, which resulted in increased

success rate and reliability in the following test cycle. The test, find and fix approach were

further iterated for two test cycles. The number of tests included in the cycle gradually increased

as the reliability of the tests improved. For the final test cycle, a total of 33 tests were performed

spread over the three components. The total success rate was 97%, with a minor error identified

during the testing. The result was however deemed sufficiently quality assured for this thesis.

The performed time measurements monitored the time from the start of the CAD automation

process until the end of the development process. The last step included in the time

measurement was excluded from the scope of this thesis but have been included in the time

measurements to mimic the previously performed time measurements.

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The development process to be timed was divided into activities and sub activities to ease the

time measurements and the ability to perform multiple measurements. The activities included

were further categorized according to the logical order of the process, being, PLM preparation,

NX, and PLM post process. The activities included in these categories can be resembled from

Figure 22 and the general CAD automation structure. The categorization and time measurement

for each activity is further described in Appendix C. The acquired time measurements from the

different subparts of the process can be seen in Table 6.

Table 6: Time measurements regarding the components outer guide vane strip, inner guide vane strip and guide

vane for the different subparts of the process.

PLM preparation [min]

NX [min] PLM post process

[min] Sum, [min]

Outer guide vane strip 4 9 20 33

Inner guide vane strip 4 9 20 33

GV 4 11 20 35

The preparational task in PLM are identical for all components and shared between them, hence

it is performed once for all three components. The times are split between the components since

their development is concurrent, implying that the total time for PLM preparation is 12 minutes.

The activities included in PLM preparation are Preparing NX and Generating new CAD

templates through cloning. Commencing is the process NX, including activities such as

Loading models, Importing parameters, Update cycle and Saving. Slight time difference

between the components can be seen. The guide vane model has more model views, hence more

loading time and time invested in checks. Furthermore, the activity PLM post process is

excluded from the thesis scope but included in the time measurements. No real time

measurements could therefore be performed for this activity. To counteract this, an experienced

component engineer performed time estimates of PLM post processing. Hight was taken to the

estimates to not undercut the reality. Since it is an estimate, the time for PLM post process is

constant. The preparational task and post process in PLM are alike for all components, implying

that the NX sub-process, which is the largest, is the source to variation. It can be seen that the

time measurements between the components are similar, with the guide vane being slightly

higher.

The acquired time measurements for the three components and comparison with manual work

and previously performed time studies by Siemens Energy can be seen in Table 7. Time

reduction expressed in percent for the automation process in Cadds5 and NX are compared to

the manual work.

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Table 7: Time comparison comparing manual work, the automation process in Cadds5 and the automation process

in NX regarding the models and drawings: Inner and outer guide vane strip and guide vane.

Manual work [min]

Automation process Cadds5 [min]

Automation process NX [min]

Outer guide vane strip 144 60 33

Guide vane 72 30 35

Inner guide vane strip 144 60 33

Sum, 360 150 101

Time reduction - 58% 72%

When comparing the sum of the times, it can be seen as already described earlier in the report

(4.1.2), that the automated process in Cadds5 reduced the development time from 360 min to

150 min. Thus, resulting in a time reduction of 58%. As previously mentioned, this was

measured in favorable conditions. Furthermore, the automation process in NX can be seen

requiring approximately 100 minutes for the development of the three diaphragms components,

which would imply a time reduction by 73% compared to the manual process. Considering the

current development volume of diaphragms, which was estimated to 20 units yearly. A time

reduction of 259 min per diaphragm, compared to manual work, would imply a total of 5180

minutes (86 hours) per year that could be saved and invested in value creating activities. Worth

mentioning is that two drawings, being, welding and machining is not included in this analysis,

something that could increase or decrease the time reduction.

The developed solution can be compared to the criteria specification (section 4.2) for a final

verification based on the demands and wishes set up in the projects initial state. Utilizing NX

and the integrated API Knowledge Fusion to achieve CAD automation met all requirements

regarding geometrical adaptation. Drawings and models can adapt to the different size options

of the diaphragm. Furthermore, the drawings are true to geometry. The solution is compatible

and fits within the existing diaphragm development process. By utilizing the automation

process, it reduces repetitive work for the user. Known technology by the company has been

utilized to facilitate further development, and the reduced time for development and quality

assurance shows promising results.

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5 Discussion

The results suggest that the developed solution would reduce diaphragm development time

while still assuring the quality that Siemens Energy inquire for. It is estimated that the developed

solution would significantly decrease time compared to manual labor and undercut the previous

CAD automation. Possible time saving for engineers could instead be invested in other value-

creating activities or in further development of CAD automation. The presented solution can

furthermore be adapted and developed to fit other components in the steam turbine or

completely other products. Standardization in some form has been an important aspect of this

project that has enabled design automation. Nevertheless, it would be an important part if a

similar process were to be implemented on another product or in an organization. The

importance of standardization is in line with Frank et al. that suggest that design automation is

best achieved through standardization and modularization [31]. Standardization through a

standard library of components which are used and reused in design automation is also

expressed by Tarkian and Amadori, in [32] and [19], respectively. Furthermore, Knowledge

Fusion in NX as a way of achieving CAD automation demonstrates promising results. The goals

and deliverables set for the project have been delivered and achieved through the generated

results. A CAD automation process that fits into the existing process as well as drawings and

models for several components have been developed. The set and achieved goal for time

reduction is considered a bonus and a quantifiable measure demonstrating the promising results

by utilizing Knowledge Fusion. Lowe et al. in [28] presents similar results where KF was used

as an automation tool for a company producing turbine engines. The study showed that the

company could reduce its development time for turbine blades from 300 – 480 min to 6 – 8

min. A time reduction greater than what was measured for this project but nevertheless

demonstrating the possibility of reducing time through the chosen solution.

The project and its schedule were divided into two almost equal parts of research and

development. The Initial research was laid out as an analysis of the current situation at the

company. This resulted in a combination of theoretical reference frame, data gathering, cost

analysis and process mapping. Data gathered from the company and its employees in

combination with the theoretical reference frame were then utilized to ensure that the developed

results was grounded in established theory. The approach added a scientific basis to the project

and simultaneously added value for the company.

The collection of data consisted of several different methods, the choice to conduct interviews

as an initial method was selected since it was considered to gain sufficient information in a

short time. The procedure to use a semi-structured interview methodology suited this project.

The interviewee had the opportunity to answer the predetermined questions and simultaneously

express their opinion and address areas or questions that they considered important. Something

that was believed to improve the interview and provide more information of unknown areas of

interest. The two other mentioned approaches, being structured and unstructured interviews

could have been adopted. However, the structured interview is thought to be too structured not

allowing the interviewee to express their thoughts. On the other side of the spectra, the

unstructured interview is lacking structure resulting in a higher probability for the interview to

drift from the subject. It can be argued that less relevant information would have been achieved

if an alternative approach to the semi-structured had been adopted.

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The number of interviewees chosen for the gathered data can be considered as the minimum

limit for how few participants should participate in a study. However, the employees at the

department with the most knowledge regarding steam turbine diaphragms as well as those who

have worked and will work with CAD automation for diaphragms were chosen. Additional

employees with relevant knowledge were not available. And although few interviews were

conducted, the answers were similar and gave a unison view of the background. The probability

that more respondents would have given a different answer that would ultimately result in a

different outcome is considered low.

The concept generation and the utilized methods provided comprehensive information on

approaches to CAD automation in NX. Both chosen methods exploit already known solutions,

implying that already existing concepts and solutions from the company and researched theories

were implemented and enhanced. Hence, the developed result for this thesis has not added any

new approach in the area of CAD automation, but rather built upon existing ones. This applies

to all solutions that were presented. The problem type that was tackled by the concept

generation can be seen as a mixture between synthesis and analysis. Methods for solving the

problem are both known and unknown, which imply clarification of the known and search for

unknown [6]. The problem type and its characteristics then evolved to a selection process of

different solutions. Furthermore, since multiple of the generated concept originated from

Siemens Energy, the author conducted an independent concept evaluation to avoid bias decision

making. The result was then discussed with the employees at the company. To further ensure

that a reliable evaluation and selection was performed, several weighting matrices could have

been set up where the weighting on the various wishes was alternated. To emulate this,

weighting and scoring were discussed from different perspectives with the supervisor at the

company. The author and the company considered the concept that best met the design

specification had been chosen.

Different methods and tools were utilized during the development of the automation process.

All of them grounded in established theory which was believed to enhance the development

process. One such tool was the MOKA methodology which served as the backbone of the

development and realization process. The three adopted activities, being Capture, Formalize

and Package formed the outline of the process where additional development tools and methods

could be integrated and utilized. Several other established methodologies similar to the MOKA

methodology exist and were considered. MOKA was ultimately chosen since the other

development tools were considered to best complement this approach.

The thesis project was started and carried out without the author having any significant prior

knowledge in NX modelling and automation. An evident modeling approach was applied

during the development of models to ensure adequate results facilitating automation. Numerous

modeling approaches were investigated, the vast majority sought the same result but applied

different approaches. The unified goal among the modelling approaches was to create a robust

model that could handle parameterization and geometrical variation. The choice of modeling

approach is not considered to have affected the results, provided that any of the established

methods that was researched is chosen. However, the fact that a modelling approach was

applied is thought to have contributed to more reliable models.

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During initial quality testing, errors causing all test to fail occurred where the cause of the error

could not be identified. The problem was thought to be hidden in the model and thus difficult

to find. Major time was invested in trying to identify the error that caused the faulty model. No

error was identified, and testing commenced. After the first test-cycle, it was identified that the

error was originating from the parameters that were entered into the model which in turn

originated from the Excel file. The behavior of the model was correct, but it assumed the wrong

shapes due to the faulty parameters imported. There were also other errors in the model in

addition to the parameter errors, implying that the model did not pass the tests. The reliability

of the first test-cycle could not be validated since the cause of the failed models was unknown.

The first test-cycle could not be recreated and was therefore retained. There is a possibility that

the initial quality test-cycle shows a worse result than what was performed. However, it is

considered something that raised the result for subsequent tests, as the models had to undergo

several thorough analyzes to identify a fault that did not exist. During the search for the hidden

error, numerous errors was identified that either had appeared in later tests or gone through

unnoticed. It should be mentioned that the quantity of quality tests performed is insufficient to

validate to quality assurance on the whole spectrum of diaphragm configurations. To do so,

more tests must be performed, something that was outside the time-scope for this thesis project.

The performed time studies were laid out considering similar conditions that would exist in a

normal working environment. Hight in the form of time extension was taken since activities

can take longer time to perform in a live situation. Giving the time measurements a conservative

view in sense of time reduction. The time measurements are considered reliable and not

improved or distorted to affect the result of the developed solution. Moreover, the time studies

were compared with older time studies and estimated times for manual labor. The time studies

for the old automation process were carried out by Siemens Energy in 2001 and then followed

up in 2010. It is not possible to verify how reliable those tests are. The time measurements were

however produced during the development of real turbines and should therefore reflect the time

required. However, the accuracy or exact start and end of the process cannot be verified.

Furthermore, the estimated times for manual work are, as described, only estimates. The margin

of error for the estimates can be major and deviate from reality. Since a quantitative

measurement for the manual activity did not exist, the estimates were the best available. In

order to minimize the error, the two most experienced component designers were therefore

asked to estimate the time for manual work. To summarize, it is probable that the developed

solution implies improvement and reduced development time. The exact time reduction in

percent can however be questioned, which otherwise should be considered as an estimate of

what results could be achieved with the presented solution.

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6 Further work

This section will comment on further work to extend or possibly improve the automation

process of steam turbine diaphragms presented in this thesis.

The thesis scope did not intend a complete CAD automation for EBW diaphragm development.

The set goals and deliverables were met, implying that more work is required to finish the

automation process for the complete steam turbine diaphragm. The author suggests the

following process and work to be performed to successfully finish the project. Start

development of the parametric models and drawings for the outer and inner ring. The parts must

be integrated into the existing assembly and their relationship in the assembly must be assured.

Once the parts are successfully working, the work with the assembly drawings, being machining

and welding, can commence. Similar quality tests as performed in this thesis should be

performed to ensure correctness and reliability of the system.

Once all parametric parts and drawings are completed and quality assured, the last activity in

the MOKA methodology, namely Activate, should be executed. This implies implementing the

system in the development process, start using it and perform maintenance [16].

The presented solution and mainly the way of CAD modelling in this thesis presents one

solution for achieving CAD automation in NX. The author did not have much experience

regarding the software NX before this project. It is therefore recommended that an employee at

Siemens Energy with experience in NX analyses the models and possibly alters them to follow

the modelling methodology of the company. Similar measures should be taken for the created

drawings. The author has however utilized the help of experienced engineers at the company to

counteract this. The drawings that have been developed during the project have been based on

older drawings created in Cadds5. This was a decision made by the author in conversation with

the supervisor at Siemens Energy. To verify that the information presented on the meets

prevailing manufacturing requirements, the employee responsible for diaphragm manufacture

in the workshop should be contacted to verify the drawings.

The presented solution sets out an approach and results of CAD automation. To further reduce

development time, the final step, structure of materials and information documents in PLM

could be automated. The activity is outside the CAD automation but included in the

development process. This step was included in the time study and is currently performed

manually with potential for automation. It should be mentioned that the time gain compared to

manual work should be measured since it is not apparent.

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7 Conclusion

This chapter present the drawn conclusions regarding the results of the thesis and performed

work. Thesis purpose, deliverables, specification, and research questions are the basis for the

conclusions drawn.

Purpose: The purpose of this thesis is to develop an automation process for creation of CAD

files used for manufacturing. The developed solution should increase the efficiency in the work

of the designers and be applicable with programs used by Siemens Energy today.

Deliverables:

− Research, present and decide the best suitable way for CAD automation for steam

turbine diaphragms.

− Develop an overall structure for how to automatically generate diaphragm

manufacturing basis in the CAD tool NX.

− Aim for one or more parts/drawings in the diaphragm for CAD automation.

The purpose set up initially in the thesis project was designed to have a strong connection with

the project's deliverables. Fulfilled deliverables would imply that the purpose of the project was

fulfilled. Based on the presented results, it can be concluded that all deliverables for the project

have been met. The developed solution reduces development time and fits into the existing

development process of diaphragm components. Both deliverables and purpose are therefore

considered to be met. It can also be concluded that the result induced all requirements from the

criteria specification to be fulfilled and the wishes to be achieved to a high degree.

7.1 RQ1

“How can a CAD automation process for diaphragms at a steam turbine developer be

designed to reduce repetitive work and decrease the development time?”

To understand the process to be automated, the viable tools and methods is considered the first

and most important step to achieve design automation. Not all processes are fit to be fully

automated and partial design automation processes should be considered. It is believed that time

reductions can be achieved through splitting the development process into multiple automation

processes or automating single parts of the process to reduce repetitive work.

The utilization of an API in combination with the CAD program to build, structure and control

the models is identified as a key attribute to facilitate automation, reduce repetitive work and

reduce development time. Multiple API alternatives where researched and recognized to

achieve CAD automation. Knowledge Fusion in combination with NX were utilized in the

thesis and demonstrates the possibilities to reduce repetitive work and decrease development

time. Parametric modeling facilitated the use of an API in the design of an CAD automation

process and allowed geometrical adaptation of the models. To achieve automation, both an API

acting as a control panel, and parametrization to allow geometrical adaptation are recognized

as key components. Furthermore, standardized appearance of the components to be automated

facilitates the development and design of an automation process and shortens the development

time.

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7.2 RQ2

“How can a CAD automation process be integrated in the already existing development

process for diaphragms of steam turbines and ensure quality?”

To enable the integration of CAD automation in an already existing development process,

several key factors have been identified throughout the project. To achieve a successful

integration, it has been identified that the integration should be included throughout the whole

project. Specific key parts are the pre-study, implementation, and post-study. The pre-study is

considered to form the foundation and a vital step allowing the conditions for integration to be

correct. The implementation is based on the results of the feasibility study and is therefore

deemed to continue to fulfill a well-integrated process. However, with importance to follow up

on the pre-study throughout the implementation. The Post study verifies the approaches taken

in previous steps. A clear foundation, implementation and follow-up are considered vital to

ensure integration into the existing process. Furthermore, in order for the implemented process

to meet the set quality requirements, the three steps above were not considered sufficient. A

quality goal to endeavor as well as testing and validation is seen as an important part of

achieving satisfactory results.

In the specific case of this project, there were several CAD automation approaches that could

have been applied for integration into the existing development process. In line with existing

literature, the author agrees that a design specification or similar documentation is considered

a key factor. The design specification clearly defines the requirements and wishes of the

designing a CAD automation process to be integrated. This approach facilitated the thesis

project in the decision of automation strategy.

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Journal on Advances in System and Measurements , vol. 7, no. 1 & 2, pp. 179-192, 2014.

[32] M. Tarkian, "Design Automation for Multidisciplinary Optimization, A High Level CAD

Template Approach," Linköpings University, Linköping, 2012.

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Appendix A

Rev 02, 2021-06-10 Emil Tellsén 1 (5)

Appendix A: Interview summaries

Summaries of the recorded material for the interviews are presented in appendix A, the material

is presented in the original language of the conducted interviews.

Intervju 1, Produktionsingenjör (Production Engineer)

- Kan du berätta om din roll och dina arbetsuppgifter på Siemens Energy? Ja, jag jobbar som

delprojektledare har hand om det mesta gällande mellanväggstillverkning i verkstaden. Där gör

jag beredningar, följer bearbetning, ser till att det finns material och resurser. Jag är med tidigt

och planerar först och ser till att det finns kostnadskalkyler till säljsidan som får offerter som

de kan leverera till kund. Sen är det väl hela vägen från att vi får hem material, gör iordning

beredning, följer den i maskiner, beställer hem program till maskiner och om det behövs ser jag

till att vi har lådor att packa det i när de är färdigkontrollerade som slutprodukt.

- Kommer du i kontakt med mellanväggar för ångturbin i dina arbetsuppgifter? Ja, tidigaste

kontakten jag har med mellanväggen är ju rent ritningsmässigt när jag gör en beräkning och

även när vi får orden så måsta jag veta hur den ser ut. Så jag jobbar mest med ritningar, det som

kommer i kontrakt med oss i verkstaden gällande CAD biten är ju att vissa delar i vissa maskiner

behöver ha solider att lägga verktygsbanor på, det görs ju idag i NX.

- Du nämnde beräkningar, vad är det för beräkningar som du gör då? Kostnadsberäkningar för

kundens skull för att se om de vill köpa nya mellanväggar, gör en offert helt enkelt. På en till

flera väggar.

- Vilket material i form av ritningar och modeller är du i behov av i ditt arbete med

mellanväggar? Vi har nyligen förnyat maskinparken, därifrån kommer behovet av att skapa

solider, tidigare har programmerarna själva fått göra solider. Många av våra maskiner har vi ju

kunnat manuellprogrammera specifikt för varje vägg. Men de maskinerna har vi skrotat ut, i de

nya maskinerna så skulle nog solider behövas, där programmerar de inte maskinerna längre.

- För de fem ritningarna som jag nämnde ovan, vet du vilken av dessa delar som behöver vad,

behöver vissa både ritning och modell? Det beror på storleken på mellanväggen, det avgör

vilken maskin det ska gå i, det kan röra sig om yttre och inre ledskeneband, men sen är det ju

ledskena, svets och bearbetning. Det beror helt på vilken maskin den hamnar i och vilket behov

vi har av en solid.

- Vad är det för typ av modell för bearbetning? Det är en bearbetningsmodell som går att göra

i NX, och detta gäller för mellanstora väggar, de allra minsta väggarna kommer vi köra manuellt

och de största väggarna som vi kan köra kommer vi till största del köra med manuell

programmering. För mellanstora väggar är det som maskinerna är utbytta och där behövs

solider.

- Om jag har förstått dig rätt, för större och mindre väggar är det bara ritningsunderlag som

behövs? Ja, det kan man säga. I nödfall kan vi köra en mindre vägg i en större maskin, men det

är inte optimalt. Därför vore det bra att få solider. Det är inga fasta mått för denna kategorisering

av mellanväggar men detaljer som ligger mellan 1200-1700mm kan uppskattas som

mellanstora.

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- Övrig information som du tycker jag borde veta? Nej.

Intervju 2, Systemingenjör inom tekniskt säljstöd (System Engineer within technical sales

support)

- Kan du berätta om din roll och dina arbetsuppgifter på Siemens Energy? Nu sitter jag som

tekniskt säljstöd på Applikationsavdelningen. Jag är inblandad i att försöka klura på vilka

kunder vi skulle kunna sälja till och vilka projekt det skulle innebära.

- Kommer du i kontakt med mellanväggar för ångturbin i dina arbetsuppgifter eller har du?

Jag kommer jobba väldigt lite med automation. Jag har suttit i 20 år på utveckling på ny-sidan.

De första fem åren byggde jag upp motsvarigheten i Cadds5. Jag sitter inte på en roll för

orderkonstruktion, jag kommer ej utnyttja det vi ska ta fram. Det kommer konstruktörerna göra

som tillhör den avdelningen. Men jag har bakgrund inom området och har gjort det förut, i olika

meningar, och så lång bakgrund i konstruktion. Det finns en hel del gjort som vi började med

på ny-sidan en gång i tiden, allt det som gjordes i Cadds5 gjorde vi i mitten på 90 talet. Vi la

ner enormt mycket tid och arbete och när det var klart så använde vi det, det funkade ganska

bra. Nu tvingas vi över till NX. Vi började med lite sådant när ny-sidan fanns men det gick ju

aldrig i mål, man la det på is. Det fanns ej motivation, behövdes ej i samma omfattning på

service.

- Vilket material i form av ritningar och modeller är du i behov av i ditt arbete med

mellanväggar? Ritningsunderlag använder jag hela tiden, men att generera ritningsunderlag

kommer jag inte göra, jag sitter snarare i steget före och gör utlägg. Jag har inte gjort särskilt

många ritningar på många år. Men jag använder materialet som skapas av en

automationsprocess. Indirekt kommer jag vara inblandad men jag kommer ej vara en användare

antagligen. Men jag är kommer vara en användare i den bemärkelsen att jag är väldigt beroende

av utläggen av ritningar.

- Vilket typ av material är du intresserad av att använda? Specifikt mellanväggar tittar jag först

och främst på ritningar, kommer jag undan med ritningar så är det bra, ibland kan det hända att

man behöver titta på 3D modeller också. Men det är inte vanligt på mellanväggar. Det händer

oftare på turbinhus och lagerbockar. Mellanväggar är mer fast i sin geometri. Men om inte annat

behövs det för att plocka fram rätt vikt på saker, för att räkna tyngdpunkt för transporter och

lyft. Idag har vi inte mycket 3D på mellanväggar. 3D modeller kan ju vara mycket värt, men

finns det så kommer det säkert användas.

- Övrig information som du tycker jag borde veta? Viktigt med tålamod, viktigt att fånga upp

alla varianter om man bygger en parameterstyrd modell.

Intervju 3, Konstruktör (Component designer)

- Kan du berätta om din roll och dina arbetsuppgifter på Siemens Energy? Jag jobbar med

konstruktionsbiten, jag gör mycket ritningar på axial och radialturbiner. Vissa jobbar bara med

det ena, men jag jobbar lite med både och. Det är mycket ritningsframtagning och konstruktion.

Om vi ska ta fram något nytt eller förbättra. Förut var jag inspektör, men det var ett tag sen.

Men annars ar det framförallt konstruktion, men ingen beräkning. Diverse konstruktion på axial

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men även på radial.

- Kommer du i kontakt med mellanväggar för ångturbin i dina arbetsuppgifter eller har du?

Vid inspektion av maskiner i drift och om det upptäcks att saker behöver bytas, du skulle vi

kunna förbättra dessa delar också, moderniserar lite. Kan vara smådetaljer som har förbättrats.

Vi säljer då in nya delar till kunden. Men ritningarna kan vara så pass gamla att det inte går att

följa, det går ej att tillverka, då måste ritningarna göras om. Men man säljer en mellanvägg när

kunden har behov av att uppdatera eller göra om eller att delarna är utdömda. Så brukar

ingången vara, och då måste vi göra nya ritningar. Då finns det EBW (elektronstrålesvetsad)

eller helfrästa eller slutsstegsmellanväggar, lite olika varianter. EBW är vanligast. Då iallafall

så vi tar fram nytt underlag, jag är inblandad i att ta fram dom. Oftast är det en annan konstruktör

som ritar och jag som granskar. Ritningsframtagningen är jag med i då.

- Vilket material i form av ritningar och modeller är du i behov av i ditt arbete med

mellanväggar? Det är sällan jag använder material som jag skapat, det är ju för att varje turbin

är skapad för det specifika ändamålet, de är ju individer. Varje mellanvägg blir en individ också,

det gör att det sällan är samma mellanväg som används någon annan stans. Vi har ej stor nytta

av det material vi redan skapat, de görs ju på samma sätt men det är sällan vi kan använda dem

igen.

- Kom du i kontakt med den tidigare automationsprocessen i Cadds5? I så fall, bra/dåligt med

den? Den började i en beräkningsfil, sen kör man i Excel och sen in i Cadds5. Nu var det ett

tag sen jag körde den, det finns andra som har bättre koll. Som jag minns det, när alla grejer var

på plats, ibland är de inte det och då kan det strula. Men om det fungerade som det skulle

fungerade det ganska bra. En nackdel var att ritningarna var schablonartade, man hade gjort

standarder, man fick fram en ritning där måtten ändrades men den var ej geometririktigt, måtten

ändrades men ej geometrin. Det var en grej som inte var så bra med Cadds5, standardmallarna

var lite missvisande och kladdiga, mycket vyer på samma ritning.

- Vad är dina tankar kring en ny automationsprocess, några krav eller önskemål? Jag vet inte

riktigt om man ska börja med lite, tex ledskeneband och göra de färdiga eller om man ska gå

på allt direkt. Man kanske ska göra en enklare version och komma så långt på alla delar. Jag ser

inga begränsningar och varför det inte skulle kunna bli lika bra som den gamla processen. Jag

tror att man skulle kunna börja med en standardutseende på en mellanvägg för att få en

tidsuppfattning om hur lång tid det tar att komma dit. Få i mål en från början tillslut och sen

utveckla fler varianter.

- Övrig information som du tycker jag borde veta? Nej, inte som jag kan tänka på.

Intervju 4, Konstruktör (Component designer)

- Kan du berätta om din roll och dina arbetsuppgifter på Siemens Energy? Jag har gjort mest

gjort ritningar. Jag ritar bara mellanväggar, mest EBW. Precis det här som ska automatiseras.

- Kommer du i kontakt med mellanväggar för ångturbin i dina arbetsuppgifter eller har du?

Jag har kört dom här programmen och gjort mellanväggar men ej tyckt det att det fungerat så

bra. Sen var jag med och försökte ta fram en tidigare automationsprocess i NX, men den blev

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aldrig klar.

- Har du arbetat både manuellt och med automationsprocessen? Jag har försökt köra med det

automatiska men det har krånglat och då får jag göra hundra saker manuellt i alla fall. Det bara

krånglar.

- Vilket material i form av ritningar och modeller är du i behov av i ditt arbete med

mellanväggar? Inget egentligen, jag skapar ritningarna. Ibland har jag gått tillbaka och tagit

gamla ritningar och använd de som mallar för nya. Men det är ju en ny ritning för varje

mellanvägg, de är ju aldrig likadana, alla är unika.

- Kom du i kontakt med den tidigare automationsprocessen i Cadds5? I så fall, bra/dåligt med

den? Ja jag har arbetat mycket med den, det var inte riktiga modeller, det var bara kladd. Det

var som editerade templater, de var inte på riktigt. Som kladdiga mallar som man editerade

texten på. De såg inte ut som originalet, det var bare en mallritning, utseendet ändrades ej om

geometrin ändrades, bara måtten. Det gjorde det krångligt, jag fick sitta och titta på en felaktig

form på någonting som är i 2D, och försöka tänka det i 3D, hjärnan gick ju sönder. Det funkade

ej. Någon form av modell vill man ju, kanske inte alla smådetaljer, men generella drag.

- Vad är dina tankar kring en ny automationsprocess, några krav eller önskemål? Jag vet inte,

det beror på. Men den ska se ut som den ska, och gärna någon form av modell, kanske på

bearbetningsnivå. Vill man ha den perfekt så tror jag att det är ett evighetsprojekt, man vill ju

gärna ha alla delar på rätt plats men jag tror inte det är rimligt.

- Övrig information som du tycker jag borde veta? Nej jag vet inte, du kommer få veta lite i

taget. Jag vet inte hur mycket du kommit in i det. Men det är bra att kolla först och se vad som

går att göra, det känns som ett jätteprojekt att göra det för noga, du märker säkert var efter.

Intervju 5, Utvecklingsspecialist inom beräkning (Development professional within

calculation)

- Kan du berätta om din roll och dina arbetsuppgifter på Siemens Energy? Jag är en sådan som

kallas ”advisory expert”, en expert på första nivån för axialångturbiner och främst med

inriktning på ångkanalskomponenterna, det som är inne i turbinhuset. Jag har jobbat med

ångturbinerna sedan 1990, så över 30 år. I början jobbade jag just mycket med mellanväggar på

konstruktion. Sen har jag jobbat på utveckling och nu service, ångkanalskomponenter har varit

temat hela tiden. Nu jobbar jag mycket med beräkningar, driftsfrågor och skadeutredningar.

- Kommer du i kontakt med mellanväggar för ångturbin i arbetsuppgifter i dagsläget? Ja det

gör jag, är det en skada på en mellanvägg är jag inblandat och så jag kör de program som vi

använder för att lägga ut turbinerna, termodynamiska programmen och programmen för

mellanväggshållfastheten. Är det någon avvikelse som ej är standardavvikelse alltså ett fel på

en mellanvägg i en turbin så är det ofta att de blandar in mig. Om det inte är de vanligaste felen.

- Hur skiljer sig arbetet som du gjorde tidigare mot det du gör nu? Mallarna som finns för

ritningarna, både för automation och manuella de har jag gjort, de som fylls i liksom. Sen har

man gjort automation där man fyller i de rutorna egentligen. Så ser de ut idag infördes för

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beskovlingen till stor del på 90 talet, mycket kommer därifrån. Jag har inte gjort

automationsprocessen, men ritningarna och ekvationerna bakom processen känner jag till.

- Vilket material i form av ritningar och modeller är du i behov av i ditt arbete med

mellanväggar? Ja, nu har det inte varit så mycket sådant som är rent strömningsgrejer på sista

tiden men annars finns det ju profilerna för och räkna och titta på om vi har skador hur påverkas

den trängsta sektionen som är en viktig del i mellanväggarna att man ritar upp och kollar hur

delningen ser ut och då använder man profilritningarna.

- Kom du i kontakt med den tidigare automationsprocessen i Cadds5? I så fall, bra/dåligt med

den? Det som var bra med den gamla processen var att mycket skedde utanför CAD, att det var

i Excel filen, mycket data räknades ut där, så man slapp att gå in i parametermodell i CAD

programmet. Men jag tror att verkstaden har tyckt att det varit jobbigt att de varit generella, från

ett konstruktionsperspektiv är det ju bra att ha få varianter.

- Vad är dina tankar kring en ny automationsprocess, några krav eller önskemål?

Parametermodeller vore bra att ha i NX också, det har funnits för andra mellanväggar men ej

EBW. Detta skulle kunna vara 3D modeller eller ett mittsnitt, eller kanske ett snitt i topp mitt

och botten där man kan se hur kanalen blir om man breder ut den. Det behöver ej vara en hel

3D modell av mellanväggen, men så man kan se strömningen i mellanväggen.

- Övrig information som du tycker jag borde veta? Kan tänka mig att du får mycket önskemål

från andra håll om många varianter. Jag tycker man ska hålla nere antalet varianter så man inte

får så mycket underhåll. När vi är en så liten organisation som vi är nu kan det bli tufft om vi

ska hålla koll på typ 20 mallar. Att man kan hantera antalet mallar på ett bra sätt.

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Appendix B

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Appendix B: Technical Drawings

Several the drawings for each component created during the quality testing is presented in this appendix. The presented drawings concern the

components outer guide vane strip, inner guide vane strip and guide vane, and will be presented in that order respectively. Sensitive company

information is censored on the drawings.

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Appendix B

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Appendix B figure 1: Outer guide vane strip configuration 1.

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Appendix B

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Appendix B figure 2: Outer guide vane strip configuration 2.

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Appendix B

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Appendix B figure 3: Outer guide vane strip configuration 3.

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Appendix B

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Appendix B figure 4: Inner guide vane strip configuration 1.

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Appendix B

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Appendix B figure 5: Inner guide vane strip configuration 2.

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Appendix B

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Appendix B figure 6: Inner guide vane strip configuration 3.

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Appendix B

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Appendix B figure 7: Guide vane configuration 1.

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Appendix B

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Appendix B figure 8: Guide vane configuration 2.

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Appendix C

Rev 02, 2021-06-10 Emil Tellsén 1 (1)

Appendix C: Time Measurements

The time measurements and the complete gathered material is presented in Appendix C. The

development process to be timed was divided into activities and sub activities to ease to time

measurements and the ability to perform multiple measurements. The activities included were

further categorized according to the logical order of the process, being, PLM preparation, NX,

and PLM post process. As displayed in Table 1, the category PLM preparation consist of Open

NX and Clone. The category NX of Load assembly in NX, Load drawings in NX, Import

parameters, Update drawings, Save assembly and save drawings. Following is the PLM post

process only containing file structure in PLM.

Appendix C table 1: Time measurements for Outer guide vane strip (OGVS), Inner guide vane strip (IGVS) and

Guide vane (GV).

All activities timed in Other are activities that are shared among the other components. It is

performed once and necessary for the other components, but not belonging to any of them. An

example of this is the first activity in the first category, Open NX. The activities included in

OGVS, IGVS and GV require NX to be opened but the activity lay outside of the core

development of these activities. It is therefore put as Other, and the times are split between the

components.