integrating quality function deployment to improve software quality by responding to customer needs

8/11/2019 INTEGRATING QUALITY FUNCTION DEPLOYMENT TO IMPROVE SOFTWARE QUALITY BY RESPONDING TO CUSTOMER

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INTEGRATING QUALITY FUNCTION DEPLOYMENT TO IMPROVE

SOFTWARE QUALITY BY RESPONDING TO CUSTOMER NEEDS

____________

A Thesis

Presented

to the Faculty of

California State University Dominguez Hills

____________

In Partial Fulfillment

of the Requirements for the Degree

Master of Science

in

Quality Assurance

____________

by

Izbat Sultana

Summer 2014


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Copyright by

IZBAT SULTANA

2014

All Rights Reserved


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THESIS: INTEGRATING QUALITY FUNCTION DEPLOYMENT TO

IMPROVE SOFTWARE QUALITY BY RESPONDING TOCUSTOMER NEEDS

AUTHOR: IZBAT SULTANA

APPROVED:

Keith A. Fulton, MSQAThesis Committee Chair

Robert Spencer, MA, MSQA

Committee Member

Pam Dunahay, MBA, MSQACommittee Member


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TABLE OF CONTENTS

PAGE

COPYRIGHT PAGE ......................................................................................................... ii

APPROVAL PAGE .......................................................................................................... iii

TABLE OF CONTENTS ................................................................................................. iv

LIST OF TABLES ........................................................................................................... vi

LIST OF FIGURES ........................................................................................................ vii

ABSTRACT ................................................................................................................... viii

CHAPTER

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

Background ............................................................................................................1

Statement of the Problem .......................................................................................4Purpose of the Study ..............................................................................................6

Theoretical Bases and Organization ......................................................................7

Limitations of the Study.........................................................................................7

Definition of Terms ................................................................................................9

2. REVIEW OF THE LITERATURE ............................................................................12

Overview of Quality Function Deployment ........................................................13

Overview of Software Quality .............................................................................15

Integration of QFD and Software Quality ...........................................................17

3. METHODOLOGY ....................................................................................................19

Design of the Investigation ..................................................................................19

Treatment .............................................................................................................20

4. RESULTS AND DISCUSSIONS ..............................................................................21

Stages of QFD ......................................................................................................21

Phases of QFD .....................................................................................................23

Software Development Life Cycle ......................................................................25


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CHAPTER PAGE

SDLC Methodologies ..........................................................................................29

Traditional Software Development Methodology .....................................29Agile Software Development Methodology ..............................................31Traditional Model vs. Agile Method ..........................................................32

Evaluation Criteria of Software Quality ..............................................................34

Categories of Software Quality ............................................................................35QFD Software Tools ............................................................................................38

QFD as a Method to Help Project Management ..................................................42

Importance of QFD in Improving Software Quality............................................43

Improving Software Quality by Listening to the VOC ..............................45Improving Software Quality by Using House of Quality ..........................49

Improving Software Quality by Reducing Cost of Quality .......................53

Drawbacks in Improving Software Quality .........................................................55Cause-Effect Relationship Analysis to Mitigate Drawbacks ...............................56

5. SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS ..............................58

REFERENCES ................................................................................................................62


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LIST OF TABLES

PAGE

1. Comparison between Traditional Model and Agile Method .........................................32

2. 5W1H Voice of the Customer Table - Software Customers ..........................................47


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LIST OF FIGURES

PAGE

1. Concept of Software Quality .........................................................................................16

2. Software Development Life Cycle.................................................................................26

3. Phases of Waterfall Model .............................................................................................30

4. Categories of Software Quality ......................................................................................37

5. PathMaker Consensus Builder Tool ...............................................................................39

6. PathMaker Brainstorm Tool ...........................................................................................41

7. Formation of House of Quality ......................................................................................52

8. Relative Costs to Fix Software Defects .........................................................................54

9. Cause-and-Effect Diagram for a Defect.........................................................................57


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ABSTRACT

Quality software fulfills customer needs and provides superior value. However,

quality is difficult to maintain without knowledge of customer feedback and a sound

methodology of design and development based on customer insight. This thesis focuses on

two questions: Is Quality Function Deployment (QFD) one of the best tools for implementing

customer feedback into product design and development so that customer needs are met?

What difference does it make during the Software Development Life Cycle if the QFD

process is used for designing and developing software products? This research reviews the

QFD methodology, its importance and application in software development, and how QFD

integration can ensure better software quality. QFD is of great value for small-scale projects,

but incorporating this tool successfully is not an easy task due to some drawbacks.

Therefore, this research discusses QFD benefits, reviews application of QFD methodology,

notes potential shortcomings, and identifies possible solutions.


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CHAPTER 1

INTRODUCTION

Background

Quality is a customer concern in todays competitive market. Customers prefer

quality products. Though customers expect quality, maintaining or improving it is not an

easy task for organizations. Organizations must be able to gather customer feedback and

incorporate customer requirements into product design and development. Organizations

must develop effective tools and techniques to maintain software quality. Quality

Function Deployment (QFD) is an effective tool for such a process. It helps

organizations capture, analyze, and incorporate customer requirements while designing

and developing products and ensures superior value for customers.

Quality Function Deployment methodology is used by manufacturing and service

industries. These industries have used QFD to listen to customers since 1960. According

to Sener and Karsak (2012), compared to other industries, the software industry was late

adopting QFD. However, over time, the software industry realized the necessity of

having extensive customer feedback and research. Therefore, software companies have

undergone a massive revolution, especially the last two decades. Due to competition,

software companies have taken significant efforts to improve software quality (Sener &

Karsak, 2012). These efforts include introduction of the latest innovative tools,

techniques, and methodologies, through which processes and results can be improved. In

the software industry, these improvements are evaluated in three categories: quality,


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efficiency, and repeatability (Nilsson, Castro, Rivas, & Arts, 2013). Moreover, some

quality enhancement techniques have been incorporated into the software development

process so that improvements are ongoing (Sener & Karsak, 2012).

Quality Function Deployment improves quality designs to fulfill customer

expectations and maximize customer satisfaction (Sener & Karsak, 2012). QFD is a

systematic methodology that integrates customer requirements into each phase of the

Software Development Life Cycle (SDLC), helping to deliver quality products. Meeting

expectations is not possible without understanding customer wants (what customers

would like to have) and needs (what customers must have). QFD helps software

companies successfully design and develop new products and services based on customer

wants and needs (Uppalanchi, 2010).

Since 1960, Quality Function Deployment has improved quality, value, and

customer satisfaction during product or service design and development stages (Ross &

Mazur, 2009). While companies primarily focus on functionality of software products, it

is also necessary to ensure price reduction by limiting poor quality costs (American

Society for Quality, n.d.). Usually, when an organization incorporates customer

requirements with software product development, they can mitigate the necessity of

reworking, fulfilling warranty claims, product returns, scrap, product recalls, and other

internal and external failure costs. Thus, poor quality costs can be reduced or avoided

(Ross & Mazur, 2009). Also, companies can add value to their products, which

eventually leads to improved software quality.


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The House of Quality is a tool used by QFD to capture and analyze current and

future customer requirements. It can help organizations incorporate customer

requirements in product design and development (Sener & Karsak, 2012). Additionally,

the current lightweight Agile Method is getting greater preference for small-scale projects

since the traditional Waterfall Model is considered more suitable for large-scale software

development projects. The combination of perfect tools can lead to improved software

quality with small-scale projects (Leau, Loo, Tham, & Tan, 2012).

The theoretical discussion of this thesis was made from the small-scale project

perspective. When organizations find their projects with few available resources, they

consider it a small-scale project. These organizations prefer to use the Agile Method

based on QFD (Kivinen, 2008). Compared to the Agile Method, the user interaction is

less in the Traditional Method. The Agile Method focuses on customer feedback at each

iteration. Since technology evolves quickly and customers want products with new

features, organizations need to be responsive to ever-changing customer requirements.

Once customer requirements are set, organizations can establish the relationship between

every pair of challenges and changes by using the QFD matrix. The relationship can be

classified as strong, medium strong, medium, medium weak, and weak. Organizations

can then determine whether change is complementary or conflicting. By incorporating

favorable changes based on the relation-type, organizations can reduce bug rates, shorten

the lifespan of the SDLC, and design and develop software more effectively and

efficiently based on customer needs (Leau, Loo, Tham, & Tan, 2012).


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Okonta, Ojugo, Raphael, and Dele (2013) argued that each software development

project varies in terms of its concept, framework, and requirements. Also, the reality is

that customer language is often different from designers and developers language. QFD

can eliminate these differences and help achieve multifunctional consensus. Typically,

QFD can be of great value gathering customersvoices to be heard in a way that is

understood by organizations and customers alike. These improvements can reduce poor

quality costs, ensure implementation of desired features, increase quality, and reduce

software development time (Okonta et al., 2013).

Statement of the Problem

Though it is not an easy task to improve software quality, organizations adopt

appropriate tools and techniques that best suit their project size and type to achieve

optimum output. To make products more appealing and acceptable to customers,

organizations work to design and deliver quality products. This paper focuses on the

issue of improving the quality of software and how QFD can help maintain and improve

quality. This thesis focuses on these two questions: Is QFD one of the best tools for

implementing customer feedback into product design and development so that customer

needs are met? What difference does it make during the Software Development Life

Cycle (SDLC) if the QFD process is used for designing and developing software

products?

The Information Technology field consistently helps maintain software quality

and seeks improvements. Though quality was a competitive advantage before

organizations gave it greater emphasis, customers require it in the current market.


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Therefore, organizations without quality products will not survive. Software companies

are aware of this crisis and try to address it during product design and development.

Software companies face many internal problems, including ineffective communication,

poor teamwork skills, inability to meet due date commitments, and products of mediocre

quality. Other problems include changing customer wants and needs, rising maintenance

costs, inability to forecast and control costs, a backlog for designing new applications,

risks associated with offering and upholding quality assurance, and risks of increased

number of defects in software development. All these problems have to be handled

carefully by software companies (Chang, Wu, & Lin, 2008). Failure to handle these

issues successfully may impact the quality of software products and result in customer

loss.

However, to overcome these crises, organizations need to address them at an early

stage. Using the Agile Method based on the QFD matrix is helpful for many small-scale

projects. This method can help track all customer requirement changes. Organizations

can use a matrix, such as House of Quality, to specify customer requirements.

Companies can weigh changing requirements based on their importance and become

responsive to changes where required. Compared to set requirements, organizations

detect product defects or areas that dont comply with desired specifications. If

organizations can incorporate changes at an early stage of product development, it may

reduce correction costs. Also, when corrective and preventive actions are taken at an

early stage, it may reverse negative impacts on finished products. They can ensure a

better quality of software products too. If customer requirements are not determined and


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analyzed earlier in process, it makes it much more difficult to incorporate changes at a

later stage of software design and development. To better understand customer needs to

improve quality, several important efforts have been taken by software companies.

Adopting the Quality Function Deployment tool aids to capture, analyze, and understand

customers. Eventually, this tool can help satisfy customers (Sener & Karsak, 2012).

Purpose of the Study

Several studies have been conducted to establish the link between QFD and

successful product or service development in the manufacturing and service sector.

However, the software industry started this analysis in the last twenty years. As a result,

researchers need to analyze extensively the integration of QFD in the software industry

and its benefits in making improved software quality (Sener & Karsak, 2012). Therefore,

the purpose of this research is to examine important differences during the Software

Development Life Cycle when the QFD process is used for designing and developing

software products. Further, House of Quality is examined for the important role it plays

to ensure software quality improvement for any small-scale project. Additionally, the

acceptance of the Agile Method for small-scale projects improves the process of

capturing, analyzing, and incorporating customerscurrent and future requirements

(Kivinen, 2008).


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Theoretical Bases and Organization

QFD has been used in manufacturing and service industries since 1972 and in the

software industry since 1987 (Kivinen, 2008). Many studies have focused on QFDsrole

in improving product quality or services in those industries. Compared to the

manufacturing and service industry, there is much less research on the role of QFD in the

software industry. However, concepts, tools, and methodologies used to improve the

quality of products or services can be applicable to software development and production

and can be used to ensure improved software quality. Therefore, many case studies and

theories used in manufacturing and service sectors were reviewed for this study.

Since software has created a significant demand among different types of

businesses, quality software is desired by their customers. Therefore, this thesis

demonstrates how to create a link between QFD methodology and continuous

improvement of software quality to help ensure customer satisfaction.

Limitations of the Study

Software quality has been enhanced substantially the last two decades. Customers

have offered feedback to improve software. However, it takes significant time to

implement these changes into software development. Also, rapid changes in the

technological environment can influence customer needs and wants. In this case, while

the final product is in the market, customer requirements often change. Eventually,

customer requirements do not match end product features. This can lead to customer

dissatisfaction since they are not getting the products they require. Moreover, innovative

products demand prompt incorporation of customer requirements into the product,


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whereas large-scale projects need more time and resources to incorporate all requirements

successfully. If QFD methodology cannot incorporate customer requirements promptly

or takes a long time to complete the process, it will not be as successful as expected.

Therefore, QFD is not considered suitable for innovative and large-scale projects.

Traditional QFD methodology only works with the Voice of the Customers

(VOC) collected through a time-consuming method, such as survey or interview. A

rapidly evolving environment causes changes in customer opinions and requirements,

leaving a gap between the collection of customer data and the end product. Therefore,

the final product may not fulfill customer needs anymore. Due to changing customer

needs, an organization might need to redesign and develop products based on a new

precedence of customer needs, which is time consuming (Sener & Karsak, 2012).

Though the application of QFD in developing software is becoming common, the

number of available or published works focusing on QFD use in the software industry is

scarce compared to the manufacturing or service industries (Sener & Karsak, 2010).

However, when requirements and practices evolve within a short period of time,

organizational strategies to handle crises vary. One organization may go for a time-

consuming approach; another may not. Some organizations may opt not to use QFD

methodology when innovating products or services. Moreover, some tools and

techniques might be suitable for small-scale projects. Therefore, limitations show the

necessity to propose common strategies for all organizations to cope with challenges and


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improve quality. This suggestion arose from information collected from the primary

credible sources, which are commonly practiced throughout the software industry.

Definition of Terms

Affinity Analysis: A team uses this to sort customersresponses into common groups by

using a consensus process.

Agile Model: The Agile Model approach is suitable for software development, aiding

organizations to be responsive to change.

Analytical Hierarchy Process (AHP): AHP is considered a formal procedure for ranking

options.

Capability Maturity Model Integration (CMMI): CMMI depicts the best practices for

software development managing, measuring, and monitoring.

Continuous Improvement: Ongoing process for the betterment of any product or service.

Correlation Matrix: This matrix shows the relation between customer demands (WHATS)

and quality characteristics (HOWS).

Cost of Poor Quality: These are costs resulting from failure to produce good quality

products or services.

Cross-Functional Team: A collection of people who have diverse expertise but the same

goal.

House of Quality: House of Quality is a QFD chart that defines and relates customer

demands and quality characteristics.


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ISO 9000 Standards of 2001: Guidelines for organizations to achieve constant customer

satisfaction.

ISO 9001-2000 Standard: Guidelines through which organizations accomplish their goal

and fulfill customer requirements.

ISO 9126-1 Model: A global standard especially designed for assessing software quality.

IT Infrastructure Library: Guidance for supporting IT services with organizational needs.

Kano Model: This is a two-dimensional model that graphically represents customer

reality and perception.

Project Management: Set of techniques to propose, plan, implement, manage, and

evaluate any project.

Quality Function Deployment(QFD): QFD is a structured process through which the

Voice of the Customers can be identified and carried out through each stage of design and

development.

Relationship Matrix: This matrix helps to determine strength to predict customer

satisfaction in terms of each demanded quality.

Rational Unified Process (RUP): RUP is a comprehensive iterative framework that guides

software companies with industry-tested practices and ensures successful Project

Management.

Scrum: An Agile structure that helps software companies successfully finish any complex

project by ensuring perfect team collaboration.

Small-scale Project: A project that doesn't have many available resources is known as a

Small-scale Project.


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Software Development Lifecycle (SDLC): The SDLC model is dedicated to software

development, which includes the process from its inception to maintenance.

Software Quality: A study that depicts desirable characteristics of software products.

Software Quality Function Deployment (SQFD): SQFD emphasizes quality enhancement

strategies during software requirementsspecification phase so that quality of the

software can be improved.

Strategic Planning: Planning related to achieving the mission and vision by using limited

resources.

Total Quality Management (TQM): TQM is a long-term approach of being successful by

satisfying customers.

Verification: Assesses work products to verify that specified requirements are met for a

certain phase.

Validation: Appraises software thoroughly, or at the end of the development phase, to

verify that particular business requirements are met.

Voice of the Customer (VOC): Customerswants and needs expressed verbally or

through written statement. Customer needs can be termed as verbatims.

Voice of the Customer Table (VOCT): A table with organized, translated, and analyzed

verbatims. It gives an idea about how a customer plans to use the product or service.

Waterfall Model: A sequential downward process for software development that includes

analysis, design, implementation, testing, and maintenance.


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CHAPTER 2

REVIEW OF THE LITERATURE

Several journal articles, white papers, and published theses were reviewed to

understand the application of QFD and use of this methodology to improve software

quality. This research led to a variety of concepts related to QFD application, which are

referenced in this paper. Kivinen (2008 and Sener and Karsak (2012) were two of the

most influential. These sources, along with additional sources listed in the references,

were extensively reviewed to establish arguments and show the role of QFD in improving

software quality. Though no article was found precisely on the same topic, this research

built upon their research and adds a new perspective on QFD application and limitations.

Though several sources touched on software quality, Chang, Wu, and Lin (2008)

served as the primary reference to focus on the role of QFD in improving software

quality. Several resources helped support this papersargument that QFD is not as

suitable for innovative products or large-scale projects. Many authors of the sources used

in this paper had active experience with QFD for many years. The data and facts

provided in this paper relate to software technology and its quality. All the materials

cited are foundational to the argument about the link between QFD and improved

software quality. The sources also helped support the logic of how reducing Cost of

Quality can play an important role in improving software quality, how the competitive

market has compelled organizations to be more proactive in rapidly responding to


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changes in customer requirements, and so forth. Overall, the research is essential to

establish the role of QFD in improving software quality by responding to customer needs.

Overview of Quality Function Deployment

QFD was first introduced in the late 1960s in Japan by Shigeru Mizuno and Yoji

Akao. Mizuno and Akao designed the product based on customer requirements before

manufacturing so that the final product would satisfy customers. The QFD

methodological transfer (from manufacturing to software industry) initially took place in

1984 while Japanese designers explored the progress of embedded software. In 1988,

Digital Equipment Corporation (DEC) proclaimed that QFD could be utilized for

software development. In 1987, Richard Zultner was the first to describe the integration

of QFD with software engineering. In 1989, Betts united the principles of QFD with the

Software Development Life Cycle (SDLC). In 1996, the term Software Quality Function

Deployment (SQFD) emerged, and further development took place with requirements

engineering (Kivinen, 2008).

QFD is considered a decision making methodology and structured planning tool

that focuses on quality while designing a product so that quality can be integrated from

the beginning. The concept of quality drives QFD to ensure the best possible product for

customers. QFD emphasizes customersneeds. QFD captures needs and translates those

specifications into part characteristics, product requirements, process plans, and

production or quality plans (Kivinen, 2008).


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In the current competitive market, organizations must recognize customersexact

needs, incorporate requirements successfully during design and development, and

measure their satisfaction after delivering the product or service. Initially, QFD

methodology captures the Voice of the Customers (VOC) and then addresses the gaps

between customer expectations and the actual products or service experience. Thus, QFD

can maintain integrity and can engender innovative techniques to achieve the

organizations vision. Moreover, QFD can help organizations diminish negative qualities

and capitalize on positive qualities. It eventually creates value that satisfies customer

needs. With the help of this methodology, organizations can concentrate on design with

quality rather than inspect quality after the product is developed. QFD might eventually

help reduce development times, promote teamwork, and lower startup costs (Uppalanchi,

2010).

With the help of QFD, companies can be proactive rather than reactive. That

means, rather than handling customer complaints, they can resolve quality problems at

the beginning or throughout the development process. Translating customer desires into

production requirements, technical attributes, and process plans is the fundamental

concept of QFD. In the case of software development, QFD adoption is termed Software

Quality Function Deployment (SQFD). SQFD can be considered a structured

methodology that concentrates on improving the quality of the software development

process so that products can be developed to meet customer expectations. This process is

possible by listening to customers throughout the design and development process (Sener

& Karsak, 2010).


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The matrix chart, or quality chart, which is known as House of Quality, is the

central tool of SQFD. This tool helps generate prioritized, quantifiable, and explicit

technical requirements collected from indistinct customer needs (Kivinen, 2008). Over

time, better tools have been developed, such as the Agile Method, which is suitable for

the smallest projects (Leau, Loo, Tham, & Tan, 2012).

Overview of Software Quality

Software quality can be evaluated by the extent to which the software complies

with customer requirements of characteristics and functions. The ISO 9000 Standards of

2001 delineate software quality as the totality of characteristics and features of any

software that fulfills oblique needs of customers. Software quality includes the following

measurements:

1. Degree of userssatisfaction compared to their expectations.

2. Degree of program maintainability and effectiveness of the system.

3. Management and control of quality.

4. Costs of project, risk management, production time, and resource control.

Software quality can be further categorized into two types: software procedure

quality and software product quality (Kivinen, 2008). Figure 1 gives a clear concept of

software quality.


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Figure 1.Concept of software quality. Adapted from Integrating Fuzzy Theory and

Hierarchy Concepts to Evaluate Software Quality, byC. Chang, C. Wu, and H. Lin,

2008, Software Quality Journal, 16, p. 263-276.

In other words, software quality is high when there are no known errors or

deficiencies. Though desired, it is difficult to provide software with zero defects.

Quality is emphasized since the consequence of poor quality is financial loss, dissatisfied

customers, and customer loss. The widespread quality standards are Capability Maturity

Model Integration (CMMI), ISO9001-2000 Standard, Total Quality Management (TQM),

and IT Infrastructure Library (ITIL). There are three basic processes to ensure better

software quality: quality planning, control, and improvement. To ensure software quality,

organizations must ensure process quality and also product quality (Kivinen, 2008).

Software Quality

Software Procedure Quality

TechnologyTools

PersonnelOrganization

Equipment

Software Product Quality

Document Clarity

IntegrityDesign Traceability

OrganizationProgram Reliability

Test Integrity


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Integration of QFD and Software Quality

The software industry was not the early adopter of QFD. Manufacturing and

service was the initial adopter. Quality has always been a significant issue in the

manufacturing and service industry. They had to incur time and costs to maintain quality

and refined the QFD tool. They detected poor quality before it reached customers.

Therefore, they reduced the cost of poor quality related to warranty claims, reworking,

customer complaints, and other costs.

Many organizations have adopted social media as a great source through which

they can reach customers and receive feedback. Social media is often used to keep pace

with rapidly changing customer needs, their feedback, satisfaction, and dissatisfaction.

Since the turn of the century, dozens of publications in the manufacturing or

service industry have been launched related to QFD. Extensive analysis and research was

needed to reach this phase of development. Over time, this information helped the

software industry to use QFD in the most effective way to obtain optimum output.

However, there are a few variations among industries in terms of product type, frequency

of customer requirement changes, and satisfaction level. Customersrequirements

change quickly and propel advances. Strategies often need to be customized. General

rules, tools, and techniques may not be suitable for all industries or projects. Social

media interactions with software companies are not that popular yet. Hence, approaches

to reach customers differ as often as the investigation method (Oke, 2013).


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QFD methodology aims to engage customers in the product development process

so that core quality is present in the end product or service and customers are satisfied

(Kivinen, 2008). Rapidly changing customer needs made the market more competitive.

Organizations now have to pay close attention to customers to survive and become

successful. Software companies use QFD to determine product design features to

achieve customer satisfaction. They also prioritize features based on their importance to

the later phase of the design process.

QFD is a productive methodology through which rapidly changing needs can be

captured and incorporated into the development process. This methodology links

marketers, customers, competitors, engineers, and production methods. Moreover, by

developing a comprehensive view of the design process, problems can be resolved at an

early stage of design, which may radically improve production. Since QFD seeks both

explicit and implicit customer needs, it helps organizations produce software that meets

customer requirements. As a result, errors decline and quality improves (Uppalanchi,

2010).

However, quality software is considered defect-free. Though it is difficult to

make any software defect-free, organizations develop the best products possible. To

ensure no known defects, organizations need to know their customersrequirements are

rapidly changing. Otherwise, the gap between expected and actual experience will hinder

the software from being bug-free. Like other industries, software organizations have

used the QFD methodology for small-scale projects so they can keep pace with changes

and fulfill customer needs (Uppalanchi, 2010).


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CHAPTER 3

METHODOLOGY

Design of the Investigation

The information gathered for this thesis was focused on the QFD concept that was

first introduced by Shigeru Mizuno and Yoji Akao. The framework for the analysis

included the concept of QFD, and its use in the software industry, as first described by

Richard Zultner in 1987 (Kivinen, 2008). This thesis focuses on why continuous

improvement of software is crucial and the quality of QFD as a solution. This paper will

not only let the reader know about the current practice of QFD in improving software

quality, but also focus on the current and more acceptable SDLC method. Problems

related to using effective tools and techniques have been emphasized and solutions

highlighted. A comparison has been made between the Waterfall Model and the Agile

Method, noting which method is most suitable. The purpose of this study is to come up

with a clear understanding about how QFD can make customers happy by ensuring better

quality software.

The thesis utilizes qualitative research and not a survey. Rather, the investigation

was based on information obtained from credible sources. However, there were some

statistical data or research findings collected from various white papers or journals. Since

no survey was conducted, the information obtained from credible sources received the

appropriate emphasis. Various statistical data, or support theories, have been used to

formulate a conclusion.


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Treatment

Each section of this paper has a brief description of QFD and concepts related to

improved software quality. Those descriptions have formed the baseline for discussing

QFD as a tool to improve software quality. Since no survey was conducted to support the

theory, each section started with an overview of the problem maintaining good quality

software and then progressed to the solution of using the QFD concept. The data or

analysis used in this paper was collected from credible sources and reliable authors.

Some data have been collected from other industry practices since those are applicable

for the software industry.

Changing customers, needs and this connection to quality production has been

emphasized. Several problems have been highlighted that impede the improvement of

software quality. With appropriate reasoning, each section has developed the best

possible solution to overcome problems related to the QFD tool. As part of the activity,

relevant data and pictures have been included to support the theory.


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CHAPTER 4

RESULTS AND DISCUSSIONS

Stages of QFD

Organizations must proceed through a step-by step process to get the optimum

output from the QFD approach. Comprehensive procedures that let organizations capture

and use the information accordingly and deliver the customers with the desired end

product include five stages (Ictenbas & Eryilmaz, 2011).

Stage 1

The first stage of QFD is to determine the requirements of customers. To begin a

QFD process, a business must listen to its customers. Feedback can be based on a survey

report, experiences, or interactions with customers. Social media has been recognized as

a great source to reach customers.

Stage 2

In the second stage, the priority structure is determined based on customer

requirements. The competitive assessment of customer requirements is also part of this

stage. For each requirement, customers can participate in deciding the organizations

position compared to competitors. This competitive evaluation can be completed through

customer survey. The customer survey may include direct interviews, questionnaire

survey, e-mail communication, interviews via telephone, and so forth.


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Stage 3

In this stage, the horizontal section of the QFD matrix is developed based on the

data collected about customers. In this segment, a list is developed with an appropriate

order. The list may contain priority rating, customer requirements, and competitive

evaluation of customer requirements.

Stage 4

In this stage, the vertical segment of the QFD matrix is developed. After

identifying customer requirements, inter-relationships between customer expectations and

design requirements are established. The design requisite can be scrutinized to verify its

co-relationship. The objective of doing this is to highlight conflicting requirements.

Column weights are calculated, allowing consideration for the importance of each design

requirement.

Stage 5

Stage five analyzes the completed QFD matrix. Based on the final ranking, team

focus is designed and arranged so that customer needs can be fulfilled. To successfully

design and develop a product with better quality, all stages should be analyzed and

implemented accordingly (Ictenbas & Eryilmaz, 2011).

Every software development process is considered a unique project, since the

time, cost, and resources required for each project is different. Whatever the size or type

of project, this five-step process is effective for successful product development. A

survey was conducted in the UK where 1500 IT Project Managers participated. Huber

(2003) found that only 16% of project managers became successful in all of their targets.


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The main reasons behind the failure included lack of user input, incomplete requirements

and specifications, and changing requirements and specifications. That means listening

to the customers over time can ensure better product design, development, and quality.

Since requirements acquisition and management are crucial to the success of any

software project, these aforementioned stages can be helpful for conducting the process

successfully (Kivinen, 2008).

Phases of QFD

In each phase of QFD, matrices are primed in planning and communicating

significant design and planning information. Throughout the small-scale software

development project, these basic four phases of QFD occur successfully. The successful

execution of these four phases eventually leads to the improved quality of the software

(Okonta et al., 2013).

Product Planning

Product planning is the first phase of QFD that includes developing the House of

Quality (HOQ). This phase is also called The House of Quality. The marketing

department of the specific software company usually leads this phase. During this phase,

documents are prepared on customer requirements, warranty data, product measurements,

competitive opportunities, and an organizations technical ability to fulfill customer

needs. This phase plays an important role to make the entire QFD process successful

since customer data is collected.


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Product Design

The second phase is usually led by the software engineering department. Creative

and innovative ideas can make a successful product design. More than concepts are

developed in this phase. Documentations are also made on software part specifications.

The most important parts for meeting customer requirements are then determined. Once

the parts are determined, the deployment starts for software development process

planning.

Process Planning

The third phase is process planning, which is usually led by the software

manufacturing engineering department. In this phase, the process of manufacturing is

flowcharted, and documentations are done on the parameters of process or target values.

Process Control

In this phase, performance indicators are used to determine progress and

performance. The high risks of the entire software development process are identified,

and actions are taken to prevent failures in this phase too. The quality assurance

department, along with manufacturing department, usually led this phase.

The four phases of QFD methodology initiates with product planning, and then

continues with product design, process planning, and process control. The later phases

also include testing, quality control, training, maintenance of equipment, and so forth

(Okonta et al., 2013). Though QFD is considered a great tool to capture the Voice of the

Customers and develop products based on that, it is not applicable for all projects.

Usually, this tool is less effective for highly innovative products. In contrary, this is more


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useful for small-scale projects. Whatever the project size, the phases would be same

though the output might vary (Sener & Karsak, 2012).

Software Development Life Cycle

Software Development Life Cycle (SDLC) is the accumulation of research,

modification, prototyping, maintenance, reuse, and other activities that influence the

development of software. This life cycle consists of some methodologies or stages

(Wang, Samadhiya, & Chen, 2011). The SDLC methodology can be of two types:

heavyweight and lightweight. The traditional heavyweight methodology example is that

of the Waterfall Model. On the other hand, a lightweight methodology example would be

the Agile Method. For small-scale projects, the Agile Method would be most effective;

for large projects it would be the Waterfall Model. The selection of the method depends

on the criteria and size of the project. If the organization prefers to go with the series of

steps for developing software, they might follow the method with five steps (Leau, Loo,

Tham, & Tan, 2012). Figure 2 can give the glimpse of the Software Development Life

Cycle.


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Figure 2. Software development life cycle. Adapted from Software Development and

Quality Problems and Solutions, by S. Wang,D. Samadhiya, and D. Chen, 2011,Procedia Computer Science, 5, p. 730-735.

Software Development Life Cycle consists of five phases: Analysis, Design,

Implementation, Testing, and Maintenance (Bassil, 2012). The five phases are illustrated

next.

Analysis Phase

In this first phase, software requirements are specified. The phase contains a

comprehensive depiction of software behavior going to be developed. This phase focuses

and defines functional as well as non-functional specifications (Bassil, 2012). Since the

entire SDLC process contains a set of tasks that transform the requirements of the users

into a software system, QFD methodology can be a great way of completing this phase,

2. Design

3. Implementation

4. Testing

5.Maintenance

1. Analysis


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through which the quality can be achieved by incorporating collected customers

requirements into product design and development (Kivinen, 2008).

Design Phase

In this phase, a plan is made to resolve any software problems. Designers and

developers describe a plan for problem-solving. Simultaneously, algorithm design,

concept design, design of software architecture, design of logical diagram, database

conceptual scheme, design of graphical user interface, and definition of data structure are

included to complete this phase (Bassil, 2012). In this phase, designers and developers

make a plan so that they can incorporate the collected requirements specified by

customers (Kivinen, 2008).

Implementation Phase

The implementation phase refers to the transformation of business and design

requirements into a solid executable database, program, software component, or website

by using deployment and programming. At this stage, operational application is created

based on written and accumulated real code. Text files are created as well as the

database. This phase contains the process of transforming the requirements (collected by

using QFD methodology) into an environment of production (Bassil, 2012). By

transforming the rapidly changing customer requirements, organizations can go for a

good quality software production in this stage that is the ultimate desire of both the

customers and the organizations (Kivinen, 2008).


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Testing Phase

The testing phase is also known as the verification and validation phase. Since

organizations are paying great attention to rapidly changing customer needs, they are

conscious about verification and validation (V&V). Through this phase, organizations

check whether software meets customer specifications and attains the desired goal or not.

The verification process assesses the software product and tests that the product satisfies

the state of affairs imposed at the beginning of the phase. In contrary, the validation

process assesses the software product throughout or at closing stages of the development

process. The objective is to verify whether requirements are incorporated into the

product. Debugging is done in this stage, where system glitches and bugs are found and

corrected accordingly (Bassil, 2012). Requirements identified through QFD

methodology can work as the base here to compare and evaluate performance to ensure

the softwares optimum quality.

Maintenance Phase

The maintenance phase is more focused on amending a software product after it

has been delivered and deployed. The objective is to improve the software quality by

correcting errors, refining output, improving performance, incorporating usersrapidly

changing requirements, increasing the reliability of the software, and so forth (Bassil,

2012).


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SDLC Methodologies

Two forms of SDLC methodologies have been used by organizations to run the

process of software development. The success of software development often depends on

the correct selection of methodology. Two types of methodologies are Traditional

Software Development Methodology (heavyweight method) and Agile Software

Development Methodology (lightweight method). Traditional software development

methodology includes methodologies like RUP, V-Model, Waterfall Method, and so on.

In this paper, the Waterfall Model and the Agile Method will be compared to contrast

their role in software development (Leau, Loo, Tham, & Tan, 2012).

Traditional Software Development Methodology

The Waterfall Model is also known as the classic life cycle, since it is considered

to be the oldest model used to develop software (Kivinen, 2008). It was first proposed by

Winston W. Royce in 1970 (Bassil, 2012). It is considered as a sequential and systematic

approach to developing software that consists of a step-by-step process that begins with

identification of customer requirements. It then progresses with planning, modeling,

construction, and deployment (Kivinen, 2008). Figure 3 depicts the different phases of

this model in a better way.


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Figure 3. Phases of waterfall model. Adapted from A Simulation Model for the

Waterfall Software Development Life Cycle, by Y. Bassil, 2012,International Journalof Engineering & Technology, 2.

The first phase of this method is dedicated to specify requirements and the

estimated time for development. Forecasting problems in different phases is also part of

this phase. In the second phase, diagrams are developed to show the technical

infrastructure. Once the design and architectural plan is accepted, software development

starts. Sometimes testing and production address weaknesses at the early phase. When

the project is almost complete, customers are invited to test the product. Once customers

confirm the products compliance with their requirements, the organization delivers the

product to them (Leau, Loo, Tham, & Tan, 2012).

The functional requirements defined in this model include the scope, purpose,

functions, perspective, attributes of software, functionalities specifications, characteristics

of users, requirements of interface and database, etc. Non-functional requirements

include limitations, constraints, and other criteria part of softwaresdesign and operation.

Analysis

Design

Implementation

Testing

Maintenance


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This type of requirement also includes the properties of testability, reliability, availability,

scalability, maintainability, quality standards, and performance (Bassil, 2012).

Agile Software Development Methodology

Agile Methodology is founded on the concept of iterative and incremental

development. In this method, the SDLC method phases evolve again and again. To

reach a solution, the customersfeedback receives more emphasis. Unlike the Waterfall

Model, the SDLC process is fragmented into small parts. They are known as iterations

or increments. The major factors of this method include adaptation to change, iterative

development, self-organizing teams, and early customer involvement (Leau, Loo, Tham,

& Tan, 2012).


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Traditional Model vs. Agile Method

Table 1

Comparison Between the Traditional Model and Agile Method

Traditional Model Features Agile Method

Rework Cost

Customer Involvement

Fixed Direction of Development Changeable

At End of Coding Phase Testing At Each Iteration

For Large-scale Projects More Suitable Low, Medium-scale Projects

Nothing Required Skills for Developers Business & Interpersonal

Note. Adapted from Software Development Life Cycle AGILE vs Traditional

Approaches, by Y. B. Leau, W.K. Loo, W. Y. Tham, and S. F. Tan, 2012,International

Proceedings of Computer Science and Information Technology, 37.

However, in the Traditional Method, user requirements are defined in detail

before implementation. On the other hand, iterative acquisition is utilized for specifying

user requirements in the Agile Method. The Agile Method can be useful for making

customers satisfied since it focuses on customer feedback. Also, this method reduces the

bug rates, shortening the lifespan of the SDLC. This method is preferable to the

Traditional Method in the current market. Organizations working on small-scale projects

choose this method to develop software. However, the Traditional Method is not extinct.

It is also being used for complex- and large-scale projects.

As a rule, organizations should choose the method that best suits their project


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type. Some factors should be considered to determine the type of the method: complexity

of the project, size of the team, type of project, engineering capability, industry

requirements, geographical location, business strategy, and so forth. This decision is

crucial for any organization since it highly influences software quality. By taking the

right decision, it becomes much easier to improve software quality.

According to Leau, Loo, Tham, and Tan (2012), there are six Agile development

methods. They are dynamic software development method, crystal methodologies,

feature-driven development, extreme programming, lean software development, and

scrum. Scrum is a well-known approach. Unlike Traditional Waterfall-based software

development methodology, Scrum is a quality driven approach based on cross-functional

teams. Testing starts from the beginning phase of software development, and all team

members contribute to the process of improving software quality. In the Scrum approach,

projects are divided into sprint. During a sprint, business analysts write user stories,

developers develop and complete unit testing, and QA analysts prepare the system test

cases in parallel and begin thorough testing right after the sprint demo at the end of the

sprint. The Scrum team is dedicated to design, develop, and deliver the software products

based on the specified customer requirements that satisfy them.

In the Traditional Method, customers or stakeholders are only met at the early

phase of the development to determine specifications. The drawback is that if defects

found at the later phase of the development, the entire module might need to be reverted

and rectified. Also, if customer requirements change, they may not be incorporated with

the end product. Therefore, quality cannot be maintained, and customer satisfaction


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cannot be achieved. On the other hand, in the Agile Method, every module is presented

to customers for review. More interaction with customers lets the organization better

understand requirements, develop and modify products based on that knowledge, reach

the goal of quality products, and satisfy customers. While interacting with customers or

collecting data, QFD methodology can be of great value to capture, analyze, and

categorize customer requirements into a structured matrix. QFD also helps incorporate

requirements with design and development and to keep requirements for future reference

(Leau, Loo, Tham, & Tan, 2012).

Evaluation Criteria of Software Quality

Once any small-scale project goes through SDLC, as well as the stages and phases

of QFD, its performance should be evaluated. The evaluation results should indicate

QFDs effectivenessfor improving software quality. Without measuring software

quality, it is difficult to improve processes or software. Therefore, the evaluation process

is crucial. Organizations assess the quality of software by measuring the following six

major attributes set by the ISO model. The ISO 9126-1 model assesses the quality of the

software in terms of functionality, reliability, usability, efficiency, maintainability, and

portability. Software quality evaluation or assessment criteria, as well as sub-criteria,

include the following.

Functionality: Functionality assesses the extent to which any software satisfies affirmed

specifications of customers, including sub-criteria of accuracy, suitability, security, and

interoperability.


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Reliability: Reliability assesses the availability of any software for use, including sub-

criteria of fault tolerance, maturity, and recoverability.

Usability: Usability evaluates the simplicity of using the software. It also includes sub-

criteria of attractiveness, understandability, operability, and learn-ability.

Efficiency: Efficiency assesses the use of resources, including sub-criteria of time and

resource behavior.

Maintainability: Maintainability evaluates any softwares ease of repairing, including

sub-criteria of satiability, changeability, testability, and analyzability.

Portability: Portability assesses how simply any software can be inverted from

environment to environment. It also includes sub-criteria of ability to install,

adaptability, coexistence, and ability to be replaced (Chang, Wu, & Lin, 2008).

Categories of Software Quality

The software industry is rapidly developing. Therefore, the concept of software

quality improvement is important. It is not only limited to planning, designing, and

developing software, but also about evaluating performance so that continuous

improvement can be made. QFD methodology can take part in the software quality

improvement process by helping organizations identify changing needs and by taking

actions for improvement in each category of software quality (Sener & Karsak, 2010).

Software quality can be classified into three areas. To improve quality, evaluation

needs to be conducted for each category, and weak areas identified. Then improvement

should take place. The three categories are Software Quality Fundamentals, Software

Quality Management Processes, and Practical Considerations.


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Software Quality Fundamentals include software engineering culture and ethics,

value and costs of quality, models and quality characteristics, quality improvement, and

so forth. Software Quality Management Processes include software quality assurance,

verification and validation, reviews, and audits. Finally, Practical Considerations include

application quality requirements, defect characterization, software quality management

techniques, software quality measurement, and so forth (Kivinen, 2008). Figure 4 depicts

categories of software quality.


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Figure 4. Categories of software quality. Adapted fromApplying QFD to Improve the

Requirements and Project Management in Small-scale Projects,by T. Kivinen, 2012.

However, software quality can be improved by going through a process of

continuous improvement that may include software quality fundamentals, software

quality management processes, and practical considerations. This improvement process

may require coordination, management control, feedback from processes and customers,

and more. A perfect software quality management process may indicate the level of

satisfaction customers have from the software product, customersperceived value for

that product, and indication of the areas that need improvement to meet customer

requirements (Kivinen, 2008).

Software Quality

Fundamentals

Software Quality

Management ProcessesPractical

Considerations

- Value and costs

of quality- Software

engineeringculture and ethics- Models and

quality

characteristics

- Quality

improvement

- Defect

characterization- Application

qualityrequirements- Software

quality

measurement

- Softwarequality

- Reviews and audits

- Verification andvalidation

- Software qualityassurance

Software Quality


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QFD Software Tools

Numerous tools can be used to assist the process through which QFD develops

software products. PathMaker is one framework for software, which can be applied to

describe the required steps necessary to run QFD methodology. Management tools are

also included that help build QFD matrix content. PathMaker includes a tool called

Consensus Builder, used to make a suitable analysis regarding the significance of

customer requirements (Kivinen, 2008). Consensus Builder helps companies determine

customers thoughts as well as prioritize requirements by voting, rating, or discussions.

Through this tool, organizations can incorporate customers feedback in their design and

product development. Figure 5 is a snapshot of PathMakers Consensus Builder Tool that

shows how this tool works to determine the Voice of the Customer. Under the Legend

criteria, customers can describe features they want to be incorporated into or eliminated

from the product. The feedback collected from voting, rating, or discussions can be used

to build the QFD matrix, such as the House of Quality. These tools aid product design

and development by ensuring incorporation of customer requirements.


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Figure 5. PathMaker consensus builder tool. Consensus Builder Tool, Skymark, 2014.

Retrieved from http://www.skymark.com/pathmaker/tour/consbldr.asp

The Cause and Effects Tool can be used to analyze and visualize the connection

between customer requirements and features. This tool arranges customer input based on

importance, so it can help identify the root causes of customer drawbacks. This tool can

be used to recognize probable causes that contribute to a single effect. In addition,

Consensus Builder can be used to allocate a value for the relationship (weak, strong, no

relationship). To record the result, PathMaker can provide QFD forms that are helpful

for building a QFD matrix.

Brainstorming and Affinity Diagram tools cartel two significant innovative

processes. Brainstorming is a tool used to collect customer requirements by focusing on

innovative ideas. This tool can be used to share information and collaborate with team


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members. Another tool, Affinity Diagram, can be of a great value to sort out

specifications and to build a group of common ideas. Once groups are made, it helps

companies think creatively and work collaboratively. In sum, it helps analyze customer

requirements, categorize critical issues, and manage opinions. QFD Capture Professional

Edition is one support tool that facilitates a process of decision making. It can set

matrices, a roadmap of lists, and documents for each software project. QFD Capture also

encloses a tool for engendering customer surveys, creating features for web page

publishing, and producing maps for market opportunity, identifying product

developments best opportunitiesand even creating a relationship tree diagram. The first

invented Windows application for QFD is QFD Designer. It includes a variety of

templates, including customer segment analysis, strategic planning, House of Quality,

failure analysis, and Voice of the Customer tables (Kivinen, 2008). Figure 6 shows a

sample list of possible causes of problems that was accumulated by using the

Brainstorming Tool. Since the causes and problems are determined based on the

customers feedback, it can be easier to figure out the errors in different phases of a

process compared to the expectations set by customers. This way, the system

development can be better as well as can satisfy the customers by fulfilling their

requirements in terms of product design and development.


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Figure 6. PathMaker brainstorm tool. Brainstorm Tool, Skymark, 2014.

Retrieved from http://www.skymark.com/pathmaker/tour/consbldr.asp

QFD methodology entails quality thinking. Due to its depth and breadth, it is

flexible, yet it may not be suitable for all companies. Indeed, it needs to be custom-

tailored. Companies must take the time to understand the methods and meaning of QFD,

then it would be possible to collect and record the outcomes of the QFD process

efficiently. However, PathMaker and other associated tools can be used to better define

and run QFD methodology. It ensures proactive product design and development rather

than a reactive one. With the help of these tools, organizations can ensure better


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execution of customer requirements while designing and developing products that can

eliminate future correction due to not meeting customer requirements (Kivinen, 2008).

QFD as a Method to Help Project Management

Dramatic economic changes, as well as globalization, have emerged amidst

intense competition. To survive, an organization needs to satisfy customers. To do that,

it must have effective strategic planning to lead successful project management.

Organizations are now using QFD Framework to gather and incorporate systematically

their customersrequirements and develop products (Ictenbas & Eryilmaz, 2011).

According to Project Management Institute, application of skills, knowledge, and

techniques to carry out projects in an effective and efficient manner is known as Project

Management (Project Management Institute, n.d.). Project Management is considered

effective when work is done within budget and on time, but customer expectations are

met accordingly (Kivinen, 2008). To survive and gain a competitive advantage, it is

important to have good strategic planning. Analysis, decisions, and actions are part of

strategic planning and are essential to lead a project successfully. House of Quality,

Waterfall Model, and Agile Method can be used as tools as part of QFD. The goal is to

help the organization listen to the Voice of the Customers, accumulate data in a

structured way, incorporate new requirements into the production process, and measure

the end product with the customer information gathered. Since QFD can help an

organization prioritize requirements and make effective decisions, it is a helpful strategic

planning tool. QFD methodology equips organizations to use their skills, knowledge, and

techniques to serve customers with the products they desire. A product is desired by


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customers when it is made with quality and has all the attributes customers want. QFD is

a tool project managers can successfully use to complete their jobs. Ideally, QFD is such

a tool that guarantees effective project management by ensuring successful strategic

planning (Ictenbas & Eryilmaz, 2011).

Importance of QFD in Improving Software Quality

Due to intense competition, maintaining quality software is vital. Though a

significant technological advancement has taken place, software developers face

problems due to incorrect and incomplete processes of identifying customer

requirements. Over time, many models have been introduced to overcome this problem,

and QFD has been considered one of the most effective tools to do that for small-scale

projects. This tool can improve software quality by capturing the voices of the customers

and incorporating those into the design and development of the software, ensuring

customer satisfaction too (Sener & Karsak, 2010).

QFD is a great technique for systematically identifying customer requirements

and prioritizing them to serve the customers with the most deserving products. By

incorporating QFD technique, organizations can design and develop an effective software

development process that ensures improved quality software. In this process,

requirements are collected from customers. After collecting specifications,

documentation is made and sent to customers for review. Once requirements are noted,

validation is done to verify consistency and completion and confirm that the specification

is internally consistent and consistent with the customersintention. Thus, QFD

methodology helps a software company define requirements, incorporate them with


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product and process, measure quality attributes, and evaluate quality. The main goal of

doing is to improve software product quality.

QFD methodology also uses the Kano model to comprehend the relating value for

a specific software product so that the desired quality can be maintained and improved

(Kivinen, 2008). Customer requirements can be defined in three forms in this case:

specification (why it is wanted by the customers), exploration (what is needed to develop

a good quality software), and design (how to develop a good quality software) (Okonta et

al., 2013).

Requirements are considered to be the basis of the software development life

cycle or process. They provide the foundation for determining cost and schedules for

developing a software product. Therefore, financial as well as functional success is

directly connected to the quality of the specifications. Many surveys have shown that

incorrect requirement specifications are the most costly mistakes to repair. The later

mistakes are found, the more expensive they become to fix. Fixing an error in

maintenance stage requires 200 times more costs than during requirements analysis stage.

The extraction of specifications aspires to discover, eloquent, disclose, and understand

the dilemma to be solved. The most significant and used means of obtaining

requirements is to consult or observe customers and stakeholders (Kivinen, 2008).

The key roles of QFD for any software development process is analyzing

customer requirements, managing quality, and developing final products successfully.

SQFD refers to the transformation of QFD technology from manufacturing product to

software development. SQFD was first initiated as an effort to improve software quality,


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used as a competitive advantage for organizations since it ensures quality of the software

based on customer requirements identified by using a matrix, such as House of Quality

(Sener & Karsak, 2010).

Finally, QFD is a widespread tool intended to serve customers with desired

products to satisfy them. A cross-functional team can design the QFD tool and ensure an

interdepartmental communication happens throughout the organization so that all

departments have the same quality focus. By developing quality tables by using the QFD

tool, improved quality can be ensured at each stage of software design and development.

Customer satisfaction can also be achieved this way since a good quality end product can

be delivered to customers (Uppalanchi, 2010). The following analysis will show how

important different concepts of QFD methodology are to improve software quality.

Improving Software Quality by Listening to the VOC

Voice of the Customer (VOC) is considered the concept that depicts the stated or

unstated needs of customers. Those stated or unstated requirements can be captured in

different ways, such as surveys, interviews or direct discussion, observation, focus

groups, customer specifications, field reports, warranty data, or any kind of social media

interaction (Okonta et al., 2013). Focus groups and interviews are considered as the

primary methods of capturing requirements from customers (Uppalanchi, 2010). From

captured requirements, a summary is made in a matrix of product planning, such as

House of Quality (HOQ). This matrix interprets WHATS(higher level) intoHOW(lower

level) requirements of products so that needs can be satisfied as well as improved quality

can be ensured (Okonta et al., 2013). In Table 2, a mock Voice of the Customer Table


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(VOCT) has been developed to give a better idea about how VOC can help improve

software quality.


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Table 2

5W1H Voice of the Customer Table Software Customers

Customer

Information

Voice of the

Customer

Context of Application

WHO WHAT WHERE WHEN WHY HOW

Software

Specialists

with

Software

Knowledge

I want quality

products as

per the

requirements,

expectations

set.

Software

Manager/

Software

Analysts

Quality

Products

At Their

Own

Premises

When

Used

Have

Knowledge

of Software

Manual/

Automated

General

Users with

No Software

Knowledge

I want quality

products in

lower price,

within next 2days, without

any defect,

lifetime

warranty,

exchange or

return option,

everything

that software

might have.

Business

man &

Writers

Everything

At Their

Own

Premises

Before

During

and

After

Use

Doesn't

Have

Knowledge

of Software

Manual

All-Time

Unhappy/

Dissatisfied

Customers

Though I

have my

product with

the desiredfeatures at a

good price, I

am not happy

with the time

you have

taken. It is not

an

extraordinary

service

experience, so

I am not

going to

spread

positive wordof mouth or

refer your

company to

others.

Anyone,

Such As

Business

man,

Software

Specialist

average

People

Everything

But Not

Contempt

In Spite Of

Getting

That

At Their

Own

Premises

24/7

Doesn't

Matter If

Has

Knowledge

Of

Software

Or Not.

Manual/

Automated

Note. Red: Explicit;Blue: Inferred


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Customers usually evaluate a software product based on its outcome or influence.

Voice of the Customer is considered to be a significant facet of QFD methodology to

assess software against determined customer requirements. To do this, current and

potential (from current and new market) customers may be interviewed and invited to

raise their voice. This way, organizations can correct and improve their products.

Ideally, capturing the Voice of the Customers lets organizations identify requirements

and incorporate those with product design and development. When customer

consequences are incorporated with a product, its outcome or influence seems to be of

good quality to their customers. On the other hand, even after delivering the software

product to customers, it is possible to evaluate product acceptance and make

improvement of areas demanded by the customers. SERVQUAL is one kind of quality

tool that evaluates software quality based on five aspects (RATER-reliability, assurance,

tangibles, empathy, and responsiveness). Organizations then can improve their quality

before and after delivery of the product (Uppalanchi, 2010).

QFD is a great tool to discover unspoken specifications of customers before

customers disclose those to competitors. Once verification and prioritization are done, a

competitive solution can be quantified that ensures software quality throughout the

process of design and development. This entire process can be successful by using table

or log of gemba visit, customer voice table, customer process model, hierarchy and

affinity diagram, and process of analytic hierarchy. However, listening to the Voice of

the Customers and using data accordingly is not an easy task. To get the optimum output,

some issues need to be emphasized. First of all, the target market needs to be identified


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as well as the customers. After that, a proper plan needs to be developed to capture

customersneeds. Then appropriate mechanisms need to be designed to collect and

organize the information. Finally, schedule and resources need to be determined to

capture the Voice of the Customers. There can be multiple voices of customers within

the same organization, such as children versus parents. Organizations pay great attention

to those diversified opinions that compel them to be more quality focused to keep their

customers. The voice of the competitors customers can also be a great source to know

about othersstrengths to achieve competitive advantage and ensure good quality.

Though the success of these techniques depends on the relationship between the

customers and the organization, but if these steps are followed properly, the approach

may be successful (Yilmaz, 2009).

Improving Software Quality by Using House of Quality

One of the four matrices of QFD includes a product-planning matrix also known

as the House of Quality (HOQ). HOQ is a widely used matrix that transforms

requirements of customers into technical traits. The objective of this matrix is to

establish the target point of technical attributes so that customer satisfaction can be

maximized (Sener & Karsak, 2010). It uses the planning matrix to create a relation

between what the customers want and how the organization would meet those

requirements (Yilmaz, 2009). Usually the HOQ consists of six components: customer

requirements, technical requirements, competitive assessment, relationship matrix,

correlation matrix, and technical priorities section respectively (Ictenbas & Eryilmaz,

integrating quality function deployment to improve software quality by responding to customer needs

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