Download - Introduction to Design for Six Sigma

Approved for Public Release, Distribution Unlimited, GDLS approved, log 2006-24, dated 04/26/06

2nd Annual Design for Six Sigma Conference

Introduction to Design for Six SigmaJames M. Wasiloff, MBB

September 14, 2006

2Approved for Public Release, Distribution Unlimited, GDLS approved, log 2006-24, dated 04/26/06

Driving SuccessDriving SuccessUsing DFSS in the Development of Battle Ships @Raytheon

Jon Mckenzie, Director of Six Sigma at Raytheon says, “in early phases of product development we use DFSS in modeling and simulation of how these

products will work. After the contract is awarded and we have firmed up exactly what we are going to build and what the system is going to look like, then we use

DFSS to derive requirements from the customer, and all the way to the critical design elements that a design engineer will need to put the parts together and

make it work”

McKenzie explained that DFSS is embedded in Raytheon’s Integrated Product Development System (IPDS), which he said “governs everything we do

in the company. If you follow IPDS, you are going to get DFSS along the way.”


Driving SuccessDriving Success"Boeing Picks McNerney as Chief" - Wall Street Journal, July 1, 2005

Jim McNerney has left his post at 3M Company where he had been the top executive for over four years to take the job as chairman, president and chief executive of the world's largest aerospace company. McNerney is globally recognized as a strong advocate for the deployment of Design for Six Sigma. The following are a sampling of quotes from McNerney while serving at 3M:

"Six Sigma is totally changing 3M. Many of the things that had driven the success of our company for the past eighty years no longer apply"

"Six Sigma is not a program. It's our game plan. It will challenge all of us. individually and collectively, to be the very best we can be"

"Major goal is to have for the first time, common approach to problem solving, new product development, and measurement across entire company"

"McNerney preaches Six Sigma to Clients... It changes everybody's lives in the first year. We're betting our performance on Six Sigma. This is something that, if Six Sigma doesn't succeed, the

company doesn't succeed."

"At 3M, Six Sigma is driven by our executive management teams, who are fully engaged in critical business processes and actively deploying Six Sigma methodologies throughout the

organization"


Driving Success

Subir Chowdhury, author of the book “The Power of Design for Six Sigma”

states in his book:

“ Most companies spend only 5% of their budget on design, when design typically would determine 70% of the cost of the product- partly because 80 % of all quality problems are unwittingly designed into the product itself. In fact, in government contracts, 30 to 40 % of the budget is set aside for testing and correcting the product. Imagine! So they are admitting in advance that one-third of the budget must be devoted to correcting the problems they plan to create with the first two-thirds of the budget. My gut says, any time testing and fixing are planned for up front, it is a virtual certainty that testing and fixing will be performed. Plan for Failure and you’ll get it”


Six Sigma: High Level PerspectiveDEFINE PROBLEM / ISSUE

StrategyPrevent defect(s)

Eliminate defect(s)

CHARACTERIZE

DEFINE

OPTIMIZE

VERIFY

MEASURE

ANALYZE

IMPROVE

CONTROL

DMAIC Black belt project toimprove mfg. capability

Mfg. process cannot provide sufficient improvement. Need DFSS project to reduce product sensitivity to mfg. noise.

DFSS DMAIC

New products Existing products?


Introduction to Design For Six Sigma

Across private industry and government/defense sectors, Design For Six Sigma is a Product Development process that:

Effectively translates the Voice of The Customer into a design Models and quantifies the design’s performance and risk Applies statistical tools to understand, optimize, and control key

factors (or develop countermeasures to…) that deliver critical customer attributes robustly in the presence of noise

Quantifies risk and facilitates business discussions regarding product delivery quality and reliability early in the Product Development process


A Historical Perspective on DFSS

Six Sigma developed at Motorola and adopted by GE and others (Steps: DMAIC)

DFSS concept originally developed at GE in late ’90s GE approach requires enhancement in the DFSS concept for

successful application to automotive industry product development: More focus on achieving Customer Satisfaction by improving

Robustness and High Time in Service performance

Aligned to defense product development practices (e.g., DVP&R, Kano Model, Robust Engineering, Reliability & Robustness checklist, etc.)


Key Elements of DFSS

Should be viewed as an enhancement to the current design process:

Bundles existing product development tools Teaches tools just-in-time at appropriate development phases Provides common 6-sigma based language for PD Not a “locked-in” process that requires the use of specified tools at

every milestone Each program may select tools according to the ability to fulfill key

DFSS elements

Is a stage-gate process Is a team and project driven process Score Card driven process Integral part of IPS and CMMI


Characterize

Gate Reviews and Project Reviews

Optimize

Verify

GateReview

GateReview

Define

GateReview

Gate Review

Project Reviews

Project Reviews

Project Reviews

Project Reviews


DFSS ScorecardSummary: Gate review tool and project summarySummary: Gate review tool and project summary

Project Team/BBs Rate Deliverables

Separates how well the team has done from the answer they got

Project Team/BBs Rate Deliverables

Separates how well the team has done from the answer they got

Key Phase Schedule: J F M A M J J A S O N D J F M A M JConcept DesignDesign DevelopmentOptimizeVerify Capability

Phase Deliverables: Owner Date Risks/Issues

1. Critical Parameter Database G G G2. G G G3. G G G4.Subsystem & Subassembly Reliability Test

Plans & Current Data/Results Summary G G G5. Say/Do Contract book Update G G G6. Marketing Plan Update / Final G G G7. Issue management G G G8. Updated Risk Mitigation Plan G G G9. Updated Integrated Schedule G G G

10. Customer Requirements Validation G G G11. G G G12. SA Checklist Complete/Approved G G G13. Business Case Update / Final G G G14.Post-Launch Product Control Plan G G G

Total Score Gate Approval G

2006

ConfidenceScore

PerformanceScore

Gate Reviewscore

System / Sub-system Robustness VerifiedOptimized Design Performance Verified

Mfg. & Supply Chain Capability Assessment

2005

Phase-Gate DeliverablesPhase-Gate Deliverables

Gate Reviewers Rate

Deliverables

Gate Reviewers Rate

Deliverables

Decision by GatekeepersDecision by Gatekeepers

goktasy

Change the slide

goktasy


Project Categories1. New programs or technologies with large design space and some

constraints (not usually a “clean sheet design”, but hopefully allows concept selection)

2. New product applications (beyond conceptual phase) for which design does not meet customer wants/functional requirements; usually, limited design space

3. Current model applications with very small design space and many constraints (high degree of optimization “tuning”)

4. New model applications with very aggressive Reliability Requirements

Project examples: New products with 10 x Reliability of legacy design


Project Prioritization Scheme

Low High High High

Low Low High Low

Critical to GDLS

Cri

tica

l to

Cu

sto

mer

Low High

Low

Hig

h


Proposed Project Selection Criteria

Impact on customer satisfaction Impact on reliability Design “degrees of freedom” Estimated cost avoidance Impact on maintainability Project duration Project complexity/scope Manufacturing location CAE model availability


DFSS Key Focus

Developing a QFD or other rigorous identification of customer rigorous identification of customer needsneeds to greater depth than is current practice

Defining or enhancing a transfer functiontransfer function, “y=f(x)” that mathematically describes “critical to satisfaction” metrics in terms of design variables

Better leveraging analytical meansanalytical means to identify & optimize critical design, manufacturing, and assembly elements

Summarizing design risk in a scorecardscorecard that captures design & manufacturing capability and enforces process discipline

Assessing field robustness robustness and using that assessment to guide verification planning & implementation


Understand Customer- and -

Understand History

Identify Critical to Satisfaction Drivers (CTS’s) and Related Functional Targets

• Flow Down to CTS’s to lower level (y’s)

• Relate CTS’s (y’s) to CTQ design parameters (x’s)

• Characterize robustness opportunities including high mileage

• Characterize capability/stability and select robustness strategy

Design for Producibility

Design for Robust Performance

Minimize process sensitivity to product & mfg. variations

Minimize product sensitivity to mfg. & usage conditions

Test & Verify

Assess Performance, Reliability & Manufacturing…Not OK

OK

Perform tradoffs to ensure all

CTS’s are met

DefineCTS’s

CharacterizeSystem

OptimizeProduct/ Process

VerifyResults

Design for Six Sigma: DCOV

DFSS Assess-

ment

Estimate for

process capability and for product function

over time

Capture data in

scorecards

Understand System- and -

Select Concepts


DFSS (DCOV) Flow of Analysis & Tools

Signifies the OPTIMUM S/N Set point…Signifies the OPTIMUM S/N Set point…

Function ModelingConcept Generation

& Selection

DoERobust Design & Tolerance Design

Functions

VOC KJ QFD

Customer Needs/Statements

Customer Requirements

FMEA

Technical Requirements

Reliability/Robustness Demonstration

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Time to Failure

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Probability Plot for time5Weibull Distribution-95.0% Conf idence Interv als

Censoring Column in censor5

ShapeScale

MeanStDev

MedianIQR

1.2257 7.8398

7.3357 6.0165

5.8135 7.3970

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40 50 60 70 80

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ShapeScale

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1.2257 7.8398

7.3357 6.0165

5.8135 7.3970

Concepts

D

C

O

V


4.0 Verify

5.0 Verify

Functionality

DFSS-DCOV Process Map

DefineCharacterize Optimize

What are the customer requirements?

What approach/ system architecture would best meet customer’s requirements?

How can we optimize forRobustness?

How can weensure thatthe customerneeds will beconsistently metin variousenvironmentsand situations?

How can we design to meet the customer needs?

What measurable system requirements supportthe customer needs?

How will we demonstrate robustness/reliability?

How can weverify that this product is reliableand robust?

Verify





& Selection

DoE

Robust Design & Tolerance Design

Functions

VOC KJ QFD



FMEA

18



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40 50 60 70 80

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ShapeScale

MeanStDev

MedianIQR

1.2257 7.8398

7.3357 6.0165

5.8135 7.3970

0.1 1.0 10.0 100.0

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2

3

5

10

20

30

40 50 60 70 80

90 95

99

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ShapeScale

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MedianIQR

1.2257 7.8398

7.3357 6.0165

5.8135 7.3970

Concepts

D


Define Phase The Define phase begins the process with a formal tie of design to Voice of

the Customer. This phase involves developing a team and team charter, gathering VOC, performing competitive analysis, and developing CTQs.

Crucial Steps: Identify and cascade customer and product requirements Establish the business case Identify technical requirements (CTQ variables and specification limits) Roles and responsibilities Establish project Milestones

Key Tools: VOC (Voice of Customer) QFD (Quality Function Deployment) KJ (Kawakita, Jiro) Kano Model Benchmarking


Gather, Process & Validate the Voice of the Customer (VOC)

• Who our customer is • The wants or needs of

the customer (Voice of the Customer)

KJ

• An affinity diagram that groups similar things of qualitative nature

• The customer’s wants orneeds translated into SystemLevel Technical Requirements

QFDVOC


KJ (Kawakita, Jiro) Analysis

Outputs:• Grouped, ranked & prioritized Customer Requirements• Customer feedback – ranked importance for each requirement, ranked

strength of competitors’ ability to fulfill the Customer Requirements

Outputs:• Grouped, ranked & prioritized Customer Requirements• Customer feedback – ranked importance for each requirement, ranked

strength of competitors’ ability to fulfill the Customer Requirements

Summary: integrate “images & visualized needs” from the customers with written Voice of the Customer inputs to obtain prioritized Customer Requirements. Summary: integrate “images & visualized needs” from the customers with written Voice of the Customer inputs to obtain prioritized Customer Requirements.

KJ Questions/Guidelines • How are customers being selected?• How will you interview the customers?• How are you facilitating selection of the NUDs? • How are the requirements being prioritized?

Conducting KJ Analysis: create affinity diagrams that gather and group VOC wants/needs and rank needs based on what is New, Unique and/or Difficult (NUDs) …


KJ Results – Voice of Consumers

Easy to use

Device must have easy to use buttons

Easy to navigate internet

Device must have easy text entry method

Few or No Dropped Calls

Dependable connection, in various environments and terrains

Good Imaging

Device must have ability to expand memory

Device must have easy picture messaging

Can go 3 days without Recharging

Provides securem-Commerce

Must support banking solution

Must provide security regarding identity

Optimized Display Size

High Resolution

Max. Screen to Phone

Supports High SpeedInternet Connectivity

The device must be able to handle data-intensive serviceDevice should be a compelling replacement for wired high speed internet

Fits lightly into A Pocket or Purse

Small size

Lightweight

Prefer Customizable at Point of Sale

Can Email Quality PhotosEasily and Quickly

The device must have a push email solution.

Device must have a simple email solution

Camera as good as stand alone

Device must have great picture quality on display

Dependable connection within building, with weak signals or strong signals

Good Entertainment

Device must have a good multiplayer gaming solutionDevice must have high quality music solution

Device must have video on demand

Must have confidence that phone will have enough power for urgent situations.


Cell Phone VOCs

Few or nodropped calls

Fits lightly intoa pocket or purse

Cell Phone Project

Can go 3 days without recharging

Can email quality photos easily &

quickly

Supports high speed internet connectivity

Provides secure m-Commerce


Quality Function Deployment (QFD)

NUDs from KJ Analysis are translated to System level Technical Requirements through Quality Function Deployment (QFD).

VOC KJ QFD

Customer Need

Statements


(NUDs)

System Level Technical

Requirements


QFD/House of Quality

Summary: Translates the Voice Of the Customer (VOC) into New, Unique and/or Difficult Technical Requirements. Identifies conflicts / tradeoffs among Technical Requirements. Links System Technical Requirements to Subsystems, Subassemblies and Components

Summary: Translates the Voice Of the Customer (VOC) into New, Unique and/or Difficult Technical Requirements. Identifies conflicts / tradeoffs among Technical Requirements. Links System Technical Requirements to Subsystems, Subassemblies and Components

Cus

tom

er Im

port

ance

HOWs (Title)

Sof tware will prov ide world class out of box experience

Ac

hiev

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hmar

kin

g to

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goa

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Win

driv

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ve

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sys

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syst

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supp

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Spe

cm

ark

impr

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Red

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Cos

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oces

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Expandable I/O

Sel

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indu

stry

st

anda

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xpa

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Opt

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terf

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to I

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Quasar must meet market window and product lif ecy cle reqts

Pro

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sta

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fo

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com

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by

reqd

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Customer Assessment

Direction of Improvement

WH

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So

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will

pr

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orld

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out

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expe

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Optimize board support package

Software compatibility and migration should be easy

Robust sof tware env ironment

Impr

ove

pe

rfor

ma

nce

4x greater perf ormance or 4x lower cost

Perf ormance =>PC

Increase perf ormance to simplify design and reduce cost

Loosely coupled processors

Ex

pand

able

I/O

Throughput as f ast or f aster than prior generation product

Qua

sar

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life

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How Much

Weighted Importance

Relative Importance

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WebSurfboard NUDs top level May 13, 2004

VOC NUD’s(from KJ Analysis)

VOC NUD’s(from KJ Analysis)

Conflicts / Tradeoffsamong


Conflicts / Tradeoffsamong


Ranked Importancefor Technical Requirements

Ranked Importancefor Technical Requirements

Technical RequirementsTechnical Requirements

Targets, Tolerances for Technical Requirements

Targets, Tolerances for Technical Requirements

1

3

2

4

5


4.0 Verify

5.0 Verify

Functionality

DFSS-DCOV

DefineCharacterize

Optimize









Verify





& Selection


Functions

VOC KJ QFD



FMEA



0.1 1.0 10.0 100.0

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2

3

5

10

20

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40 50 60 70 80

90 95

99

Time to Failure

Pe

rce

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ShapeScale

MeanStDev

MedianIQR

1.2257 7.8398

7.3357 6.0165

5.8135 7.3970

0.1 1.0 10.0 100.0

1

2

3

5

10

20

30

40 50 60 70 80

90 95

99

Time to Failure

Pe

rce

nt



ShapeScale

MeanStDev

MedianIQR

1.2257 7.8398

7.3357 6.0165

5.8135 7.3970

Concepts

C


Characterize Phase The Characterize phase emphasizes CTQs and consists of identifying

functional requirements, developing alternative concepts, evaluating alternatives and selecting a best-fit concept, deploying CTQs and predicting sigma capability.

Crucial Steps:Formulate and select concept design

Identify potential risks using FMEA For each technical requirement, identify design parameters (CTQs) using

engineering analysis such as simulation Robustness Strategy Use DOE (design of experiments) and other analysis tools to determine CTQs

and their influence on the technical requirements (transfer functions)

Key Tools: Risk assessment and FMEA Engineering analysis and simulation DOE (Design of Experiments) Critical Parameter Management (CPm) Design tools like TRIZ, Axiomatic Design, Functional Modeling, Pugh


CPM - a Disciplined MethodologyCPM is a disciplined methodology to capture the product performance into a structured repository.

Marketing

Design

SystemsEngineering

SubjectMatter

Experts

MFG

Suppliers

Standards

Partners

CriticalParameter

Management(CPM)


CPM – The Strategy

Outputs:• Capability Growth Index (CGI)• Predicted capability (Cp, Cpk) for meeting Critical Customer Requirements

Outputs:• Capability Growth Index (CGI)• Predicted capability (Cp, Cpk) for meeting Critical Customer Requirements

Product Launch

Higher Layer Cp/Cpk

System Capability Cp/Cpk

Transfer Function

System Requirements

CPM Flow Down

Lower Layer Cp/Cpk

Subsystem Requirements

Modeling

Opt

imize

Verify

Design Requirements

KJ QFDVOCConcept

Summary: Creates a formal link between the product’s design & customer needsSummary: Creates a formal link between the product’s design & customer needs


Function Modeling

Summary: Develop an architecture-independent (unbiased regarding possible solutions) hierarchy of functions through functional diagrams that illustrate the flow of functions within and across the technical requirements. The results are used during system architecting and design.

Summary: Develop an architecture-independent (unbiased regarding possible solutions) hierarchy of functions through functional diagrams that illustrate the flow of functions within and across the technical requirements. The results are used during system architecting and design.

Output:• Functional Flow Diagrams

Output:• Functional Flow Diagrams

Function Modeling Guidelines • Be sure to consider all of the key functions.

• Be sure to capture all the key flows.


Theory of Inventive Problem Solving (TRIZ)

Summary: Generate alternative Concepts to fulfill the Technical Requirements, using innovative approaches such as the TRIZ (Theory of Inventive Problem Solving) to overcome tradeoffs among the technical requirements. The candidate concepts are evaluated using the Pugh approach.

Summary: Generate alternative Concepts to fulfill the Technical Requirements, using innovative approaches such as the TRIZ (Theory of Inventive Problem Solving) to overcome tradeoffs among the technical requirements. The candidate concepts are evaluated using the Pugh approach.


Pugh Concept Selection Matrix

Summary: Compares and selects best ideas & concepts using a simple system of “better than”, “worse than”, and “same” scoring. Identifies best features from each concept and creates hybridized solutions.

Summary: Compares and selects best ideas & concepts using a simple system of “better than”, “worse than”, and “same” scoring. Identifies best features from each concept and creates hybridized solutions.

Criteria / Concept 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Ease of achieving 105-125 DbA S - + - + + - - - - S +Ease of achieving 2000-5000Hz S S N + S S + S - - - S +Resistance to corrosion, erosion & water - - O S - - S - + - - - SResistance to vibration, shock & acceleration D S - T S - S - - S - - - -Resistance to temperature A S - S - - - S S - - S SRsponse time T S - + - - - - S - - - -Complexity: number of stages U - + E S + + - - - + + - -Power consumption M - - V + - - + - - - - S +Ease of maintenance S + A + + + - - S + + S -Weight - - L + - - - S - - - - +Size - - U S - - - - - - - - -Number of parts S S A + S S - - + - - S -Life in service S - T + - S - - - - - - -Manufacturing cost - S E - + + - - S - - - -Ease of installation S S D S S + - S - - - S -Shelf life S S S S - S S S S S S

0 6 10

2 9 5

8 1 7

3 9 4

5 7 4

3 12 1

0 11 5

2 8 6

2 13 1

2 13 1

0 8 8

4 9 3

+ - S

Each concept compared

against “best in class” datum

Each concept compared

against “best in class” datum

Concepts listed along top of

matrix

Concepts listed along top of

matrix

Customer & GDLS desired criteria listed along side of

matrix

(from top of QFD HOQ)

Customer & GDLS desired criteria listed along side of

matrix

(from top of QFD HOQ)

Concepts are compared in terms

of fulfillment of criteria

Concepts are compared in terms

of fulfillment of criteria


FMEA (Failure Modes & Effects Analysis)

Outputs:• Ranked group of failure modes • Impacts of failures on customer, product or process• Risk Priority Numbers (RPN) before and after corrective action • Corrective action to remove or reduce the risk or impact of a failure mode

Outputs:• Ranked group of failure modes • Impacts of failures on customer, product or process• Risk Priority Numbers (RPN) before and after corrective action • Corrective action to remove or reduce the risk or impact of a failure mode

Potential Failure Modes

Potential Failure Effects S

EV Potential

Causes OC

C

RP

N

Controls

FMEA worksheet for identifying the failure modes with the highest

RPN

FMEA worksheet for identifying the failure modes with the highest

RPN

Summary: Failure Modes and Effects Analysis is a structured method for identifying & ranking the significance of various failure modes of the program & their effects on the product or customer

Summary: Failure Modes and Effects Analysis is a structured method for identifying & ranking the significance of various failure modes of the program & their effects on the product or customer

FMEA Guidelines • The FMEA session should include adequate

representation of key people with input on risks.• When will you implement corrective actions for

the highest RPN failure modes?


Design for Manufacturability & Assembly

Identifies part consolidation opportunities Exposes manufacturing, assembly, quality,

service and cost problems early in the design process

Objectively assesses design simplification opportunities

Drives optimization of product costs Allows setting of target costs


Optimizing for Manufacturing & Assembly Reduces Overhead Costs

Fewer parts Less material to inventory Fewer assembly stations Less automatic assembly equipment Less dedicated fabrication tooling Less paperwork and drawings

Fewer subassemblies and operations Fewer work holders Fewer assembly tools and fixtures


Design for Manufacturability & Assembly (DFM) – Key Points to Remember

Design parts for ease of fabrication Simple geometry Few process steps Make with existing equipment & tooling or can be

easily contracted out Geometry allows easy machine tool access to

machined surfaced Not too small or too large for existing processes Usual tolerances (not too tight)


Eliminate Parts by Integration

Welding

Weldingor

Caulking

Eliminate Welding Operation


Reduce the Number of Parts

Label Letters are molded

Assembly Cost Reduction: 100%

Mold message onto surface Eliminate parts by integration Reduce assembly time


Reduce Fastener Count

Note: NCR study estimated that each screw eliminated

saves $12K in life cycle costs!


4.0 Verify

5.0 Verify

Functionality

DFSS-DCOV

Define CharacterizeOptimize









Verify





& Selection


Functions

VOC KJ QFD



FMEA



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40 50 60 70 80

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Time to Failure

Pe

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ShapeScale

MeanStDev

MedianIQR

1.2257 7.8398

7.3357 6.0165

5.8135 7.3970

0.1 1.0 10.0 100.0

1

2

3

5

10

20

30

40 50 60 70 80

90 95

99

Time to Failure

Pe

rce

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ShapeScale

MeanStDev

MedianIQR

1.2257 7.8398

7.3357 6.0165

5.8135 7.3970

Concepts

O


Optimize Phase The Optimize phase requires use of process capability information and a

statistical approach to tolerancing. Developing detailed design elements, predicting performance, and optimizing design, take place within this phase.

Crucial Steps: Assess process capabilities to achieve critical design parameters and meet

CTQ limits Optimize design to minimize sensitivity of CTQs to process parameters Design for robust performance and reliability Establish statistical tolerancing Optimize sigma and cost

Key Tools: Design for Manufacturability and Assembly Process capability models Robust design Monte Carlo Methods Tolerancing and Tolerance Design Optimization tools like DOE, Response Surface Methodology, Multiple Y


Response Surface Methods

Summary: Designed Experiment for optimizing the performance of a Response (Y). Summary: Designed Experiment for optimizing the performance of a Response (Y).

Output:• Set points for the vital x’s to optimize the mean value of the Response (Y)• Set points for the vital x’s to optimize the standard deviation of the Response• Mathematical Model (transfer function) of the Response as a function of the vital x’s.

Output:• Set points for the vital x’s to optimize the mean value of the Response (Y)• Set points for the vital x’s to optimize the standard deviation of the Response• Mathematical Model (transfer function) of the Response as a function of the vital x’s.

NP

N B

eta=

50

NP

N B

eta=

102.

5

NP

N B

eta=

155

NP

N B

eta=

207.

5

NP

N B

eta=

260

NP

N B

eta=

312.

5

NP

N B

eta=

365 Impl SR=1500

Impl SR=1700

Impl SR=1900

Impl SR=2100

Impl SR=2300

Impl SR=2500

14.2

14.4

14.6

14.8

15

15.2

15.4

Response Surface - Regulation Voltage

44


Goals of Robust Engineering

1 - Identify the ideal function for the product or process design

2 - Through multi-variable experimentation, chose the nominal design parameters that optimize performance in the presence of factors that cause variability at the lowest cost. This is done through two step optimization process: Step 1: Minimize Variability Step 2: Shift mean to Target


Robust Design – P-Diagram

3) Customer Usage and Duty Cycle:

4) External Environment Conditions:

5) Internal Environment (System Interaction):2) Wear Out:

1) Piece to Piece Variation:

Ideal FunctionItemSignal

Error StatesControl Factors

(Customer Intend) (Intended Result)

(Noise Factors)

(Unintended Result)

12

3

4

5


Step 1 -Minimize Variability

Req

uire

men

t

Tar

get

Pro

babi

lity

Den

sity

Performance


Step 2 -Shift Mean to Target

Req

uire

men

t Tar

get

Pro

babi

lity

Den

sity

Performance


4.0 Verify

5.0 Verify

Functionality

DFSS-CDOVConcept

Generation&

Selection

Design Optimize









Verify




Functional ModelingConcept Generation

& Selection


Functions

VOC KJ QFD



FMEA



0.1 1.0 10.0 100.0

1

2

3

5

10

20

30

40 50 60 70 80

90 95

99

Time to Failure

Pe

rce

nt



ShapeScale

MeanStDev

MedianIQR

1.2257 7.8398

7.3357 6.0165

5.8135 7.3970

0.1 1.0 10.0 100.0

1

2

3

5

10

20

30

40 50 60 70 80

90 95

99

Time to Failure

Pe

rce

nt



ShapeScale

MeanStDev

MedianIQR

1.2257 7.8398

7.3357 6.0165

5.8135 7.3970

Concepts

V


Verify Phase The Verify phase consists of testing and verifying the design. As increased

testing using formal tools occurs, feedback of requirements should be shared with manufacturing and sourcing, and future manufacturing and design improvements should be noted.

Crucial Steps: Prototype test and validation Assess performance, failure modes, reliability, and risks Design iteration Final phase review

Key Tools: Accelerated testing Reliability/Robustness Demonstration and Growth FMEA Disciplined New Product Introduction (NPI)


Design Verification

Product Design Verification Functional Performance Verification Operational Environment requirements verification Reliability requirements verification Usage requirements Verification Safety requirements verification

Manufacturing Process Verification Process Capability verification Production Throughput Verification Production cost verification


Reliability Assessment

Measure reliability performance of Robust subsystems, subassemblies, and components Predicted reliability vs. Measured Reliability Reliability Growth Activities

• Measure Reliability, Availability and Maintainability (RAM) of equipment, manufacturing processes and assemblies.


Questions to Ask to Ensure I have Selected an Appropriate Individual as a Lean Six Sigma Black Belt Candidate

High (2) Med (1) Low (0)

Executes both effectively and efficiently?

Demonstrated change agent?

Remains on task, not easily sidetracked?

Thinks logically, connects Y to projects?

Possesses executive presence?

Thinks strategically and acts tactically?

Understands business and customer needs?

Aptitude for LSS and statistics?

Follows program management methodologies?

Propensity to both learn and teach?

Strong candidates will have scores of 15 and higherJ. Wasiloff 4 Jan 2006


Strategic Project Selection

Typically need four to five ideas to generate one good Design for Six Six Sigma project

Some projects may be cancelled during one of the phases of the process

Employ a methodology for consistent ranking of projects Ensure you have a plan for gathering ideas.

Top down Best impact on customer or ROI Aligns with strategic goals

Bottom up Knows the problem processes Knows the customer best Influences cultural change


Training References (External)

American Supplier Institute (ASI) American Society for Quality (ASQ) Eastern Michigan University University of Michigan Moresteam University (on-line) PDSS Six Sigma Management Institute Sigma Pro SBTI


Literature References Creveling, Clyde M., Slutsky, Jeffrey Lee and D. Antis, Design for Six Sigma in

Technology and Product Development. Prentice Hall, 2002

Yang, Kai and El-Haik, Basem. Design for Six Sigma: A Roadmap for Product Development

Fowlkes, William Y. and Creveling, Clyde. Engineering Methods for Robust Product Design. Addison-Wesley, 1995.

O'Connor, Patrick D. T. Practical Reliability Engineering. John Wiley and Sons, 1991.

Reklaitis, G. V., Ravindran, A. and Ragsdell, K. M. Engineering Optimization. John Wiley and Sons, 1983.

Suh, Nam P.. The Principles of Design. Oxford University Press, 1990.


Q&A

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