Task or Activity Tool Page

Prioritize/Narrow Focus

Analytic Hierarchy Process (AHP) 21Multi-Voting 195Nominal Group Technique 197Pairwise Comparison 201Pareto Chart 213

'H¿QH�D�3URMHFW�RU�6WXG\Project Charter 233Quality Function Deployment (QFD) 243

Generate and SelectDesign Concepts

Axiomatic Design 31Cause and Effect Diagram (CE) 57Pugh Concept Selection 237TRIZ 305

Collect Data

&RQ¿GHQFH ,QWHUYDOV 63Design of Experiments (DOE) 79Measurement System Analysis (MSA) 177Sample Size 263Simulation 275

Assess MeasurementSystem Capability

Capability Analysis 39&RQ¿GHQFH ,QWHUYDOV 63Measurement System Analysis (MSA) 177

'H¿QH�DQG�0DQDJHRequirements

Critical Parameter Management (CPM) 73IPO Diagrams 165Kano’s Model 169Quality Function Deployment (QFD) 243Voice of the Customer (VOC) 311

Perform Functional AnalysisAxiomatic Design 31Failure Mode and Effect Analysis (FMEA) 117System Diagrams 287

'HWHUPLQH 6LJQL¿FDQWVariables and Effects

(Assess Impact)

Cause and Effect Diagram (CE) 57Design of Experiments (DOE) 79Historical Data Analysis 135Hypothesis Testing 151Pareto Chart 213Parameter Design (Robust Design) 205Regression Analysis 251Sensitivity Analysis 269Tolerance Allocation 293

Predict Performance

Capability Analysis 39Design of Experiments (DOE) 79DFSS Scorecard 101Expected Value Analysis (EVA) 109Histograms 131Historical Data Analysis 135Probability Distributions 217Regression Analysis 251Simulation 275Transfer Functions 303

Evaluate and Mitigate Risk

Axiomatic Design 31Control Plans 69Failure Mode and Effect Analysis (FMEA) 117Probability Distributions 217Tollgate Review 299

Optimize Performance

Design of Experiments (DOE) 79Expected Value Analysis (EVA) 109Historical Data Analysis 135Parameter Design (Robust Design) 205Tolerance Allocation 293

Evaluate/Assess/Improve Design

Axiomatic Design 31Capability Analysis 39Design for X-Ability (DFX) 77DFSS Scorecard 101Expected Value Analysis (EVA) 109Lean Concepts 173Reliability 257Statistical Process Control (SPC) 279

Design for Robustness/Evaluate Robustness to

Noise

Design of Experiments (DOE) 79Failure Mode and Effect Analysis (FMEA) 117IPO Diagrams 165Parameter Design (Robust Design) 205Regression Analysis 251

Validate Performance

Capability Analysis 39Design of Experiments (DOE) 79Gap Analysis 125High Throughput Testing (HTT) 127Sample Size 263

Control /Hold GainsControl Plans 69Gap Analysis 125Statistical Process Control (SPC) 279

vContents

Contents

Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viiAcknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

Introduction to Design for Six Sigma (DFSS)1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Introduction to DFSS Software 2. Described in this Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7The Identify Phase3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11The Design Phase4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13The Optimize Phase5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15The Validate Phase6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17DFSS Tools7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

7.1. Analytic Hierarchy Process (AHP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217.2. Axiomatic Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317.3. Capability Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397.4. Cause and Effect Diagram (CE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 577.5. Confidence Intervals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 637.6. Control Plans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 697.7. Critical Parameter Management (CPM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 737.8. Design for X-Ability (DFX) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 777.9. Design of Experiments (DOE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 797.10. DFSS Scorecard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1017.11. Expected Value Analysis (EVA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1097.12. Failure Mode and Effect Analysis (FMEA) . . . . . . . . . . . . . . . . . . . . . . . . . . 1177.13. Gap Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1257.14. High Throughput Testing (HTT). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1277.15. Histograms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1317.16. Historical Data Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1357.17. Hypothesis Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1517.18. IPO Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1657.19. Kano’s Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1697.20. Lean Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1737.21. Measurement System Analysis (MSA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

vi

7.22. Multi-Voting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1957.23. Nominal Group Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1977.24. Pairwise Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2017.25. Parameter Design (Robust Design) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2057.26. Pareto Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2137.27. Probability Distributions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2177.28. Project Charter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2337.29. Pugh Concept Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2377.30. Quality Function Deployment (QFD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2437.31. Regression Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2517.32. Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2577.33. Sample Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2637.34. Sensitivity Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2697.35. Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2757.36. Statistical Process Control (SPC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2797.37. System Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2877.38. Tolerance Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2937.39. Tollgate Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2997.40. Transfer Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3037.41. TRIZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3057.42. Voice of the Customer (VOC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .311DFSS Best Practices and Trends8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315DFSS Roadmap and Tollgates9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .319

Appendix I: DFSS Tool Matrix (By Task) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323Appendix II: DFSS Tool Matrix (Alphabetical) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .327Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .331Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333

viiPreface

Preface

While there are several books on the market that provide detailed training on Design for Six Sigma, practitioners have asked for a quick reference guide covering DFSS

tools that integrates supporting software. We are pleased to provide such a book. A brief overview of DFSS is given; however, we expect that users of this book are

familiar with the topic already. The Identify, Design, Optimize, and Validate (IDOV) methodology is described, along with important milestones and tollgate questions. The key tools used throughout the DFSS process are summarized. For each tool discussed, examples are given and helpful hints are provided.

What sets this book apart from traditional resources on the market is the integration of DFSS software. The following software packages are used and referred to in the book: SPC XL 2007, DOE Pro XL 2007, and DFSS Master 2007. This software contains many useful tools and features for the DFSS practitioner. After a particular tool is described in the book, we show how to use and interpret that tool’s supporting software (when applicable). The book is written so that even those not using the software can still gain practical insight and summaries about the DFSS tools.

Whether you are just starting your DFSS journey or you are a seasoned practitioner, this book will be useful in many ways. While in training, the book is an encyclopedia of many of the tools you’ll study. Beyond the classroom, it is a helpful refresher as you apply the DFSS process. The front and back inside covers provide handy DFSS tools usage matrices that map tools to tasks within the DFSS IDOV process.

Finally, the book may be used for brief, just-in-time training of team members who are assisting with DFSS project work and may have no formal DFSS training.

ixAcknowledgments

Acknowledgments

Teamwork is a critical ingredient to success. Were it not for teamwork, this book would not exist. Although our names are listed as authors, we wish to thank our

friends, colleagues, and clients who participated with us in this journey. Your suggestions, encouragement, inspiration, editing, and support are greatly appreciated. The following is, no doubt, only a partial list of those who have contributed in some form or fashion.

Special thanks go to Lou Schneider and Jeff Koff of Xerox, and Chuck Roe of General Dynamics Land Systems, who first motivated us to consider writing this book and who made numerous suggestions along the way.

We also acknowledge the special efforts of the combined executive publishing team of Rick Murrow, Sue Darby, Mike Cyger (founder of CTQ Media), Frank Ducceschi (publisher for CTQ Media), and Jamie Friddle (project editor), all who provided the instantaneous support and barrier busting needed to make this book a timely reality.

And most importantly, thanks to our families (Mike and Katie Reagan; Carol, Kyle, Lauren, and Mom Kiemele) who stood by us and encouraged us as we created this book. Each gave up precious personal time to see this effort completed.

It is our sincere hope this book will make you a better problem solver and prove invaluable in your DFSS journey.

Murray AdamsBob BarnesRich BoucherBobby CarrollMichael CygerSue DarbyDan DenlingerFrank DucceschiFardin Farzaneh-

MoayyadRussell FordNorm FowlerJamie Friddle

Vik GanesanJeff GreensteinJames GroverJeff HastieLe’ HayesSuellen HillSteve HoyleKevin JohnsonJeff KoffJim KoglerRich KramerNorm KucharSteve LeClaire

Neal MackertichGeorge MaszlePhilip MayfieldRick MurrowTerry NewtonPrasanna NirgudkarTodd O’ConnellMatt PallaverCatherine PalmerCharlie PeckMark PetrottaLee PollockSofia Pombrik

Debbi RadkeDarian RashidNancy ReesChuck RoeDenise RuckerRudy (in memoriam)Steve SchmidtLou SchneiderBob SheaMichael SlocumCorky StevensKathi SwagertyDoug Vaughn

1Introduction to Design for Six Sigma (DFSS)

1. Introduction to Design for Six Sigma (DFSS)

1. I

nt

ro

to

DFS

S

Fig. 1.1.

Design for Six Sigma (DFSS) is a highly disciplined approach to embedding the principles of Six Sigma as early as possible in

the design and development process. When problems are not discovered until well into the product

life cycle, the costs to make changes, not to mention intangible costs, such as customer dissatisfaction, are considerable (see fig. 1.1 below).

Traditional Six Sigma is applied to processes or products that currently exist. The Define, Measure, Analyze, Improve, Control (DMAIC) methodology is used as a structured approach to analyzing the root causes of poor performance and making improvements. However, when processes or products have not yet been developed, the DMAIC methodology can be problematic to apply. For example, the “Measure” phase of DMAIC requires a measure of current performance to get a baseline. For new processes or products, such baseline data will not exist. Thus, when applying Six Sigma to new process and product development, an alternative methodology (or roadmap) is used.

DESIGN FOR SIX SIGMA: The Tool Guide for Practitioners2

The DFSS methodology described in this book has four phases:

The IDOV four-phase DFSS process originated with Dr. Norm Kuchar, formerly of General Electric Corporate R&D and who led GE’s worldwide deployment of DFSS, and is used by permission. It should be noted that other acronyms often are used to describe the DFSS methodology, such as DCOV (Define, Characterize, Optimize, Verify) and DMADV (Define, Measure, Analyze, Design, Verify). Unfortunately, there is no standard convention used across industry. In this book, we will not spend time reviewing all the acronyms, as this is not the most important part of DFSS. It is not the label you use, but rather the disciplined, systematic, and rigorous approach to producing the required deliverables that is most important in DFSS. Regardless of whether you use IDOV, DCOV, DMADV, or any one of the other countless acronyms, the basic steps and methodology remain constant. Furthermore, unless a company

Fig. 1.2.

Identify … the voice of the customer and business

Design… the product or service to fulfill those

requirements

Optimize… the product or service to deliver excellent

performance, balancing cost and time to market

Validate … the performance and results