Failure Mode and Effect Analysis: FMEA From Theory to Execution

By D.H. Stamatis

Author D. H. Stamatis has updated his comprehensive reference book on failure mode and effect analysis (FMEA). This is one of the most comprehensive guides to FMEA and is excellent for professionals with any level of understanding.!--nl--This book explains the process of conducting system, design, process, service, and machine FMEAs, and provides the rationale for doing so. Readers will understand what FMEA is, the different types of FMEA, how to construct an FMEA, and the linkages between FMEA and other tools. Stamatis offer a summary of tools/methodologies used in FMEA along with a glossary to explain key terms and principles. The updated edition includes information about the new ISO 9000:2000 standard, the Six Sigma approach to FMEA, a special section on automotive requirements related to ISO/TS 16949, the “robustness” concept, and TE 9000 and the requirements for reliability and maintainability. Also includes FMEA forms and samples, design review checklist, criteria for evaluation, basic reliability formulae and conversion failure factors, guidelines for RPN calculations and designing a reasonable safe product, and diagrams, and examples of FMEAs with linkages to robustness.

• Language: English
• Publisher: ASQ Quality Press
• Release date: May 7, 2003
• ISBN: 9780873895743

D.H. Stamatis

D. H. Stamatis is president of Contemporary Consultants Company, specializing in management and organizational development and quality science applications. With more than 30 years of experience in management and quality training consulting, he has served in numerous private sector industries including steel, automotive, machine tool, electronics, food, chemical, and military. Stamatis is a CQE, a certified manufacturing engineer, and a certified ISO 9000 lead assessor.

Book preview

Failure Mode and Effect Analysis

FMEA from Theory to Execution

Second Edition

Revised and Expanded

D. H. Stamatis

ASQ Quality Press

Milwaukee, Wisconsin

American Society for Quality, Quality Press, Milwaukee 53203

© 2003 by ASQ

All rights reserved. Published 2003

Library of Congress Cataloging-in-Publication Data

Stamatis, D. H., 1947–

Failure mode and effect analysis : FMEA from theory to execution / D.H. Stamatis.—2nd ed.

p. cm.

Includes bibliographical references and index.

ISBN 0-87389-598-3

1. Reliability (Engineering) 2. Quality control. I. Title.

TS176.S7517 2003

620'.00452—dc21 2003005126

No part of this book may be reproduced in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher.

Publisher: William A. Tony

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Table of Contents

List of FMEA Samples Found in Appendix D

List of Figures

List of Tables

Preface

Acknowledgements

Introduction

Chapter 1. Legal Approach to Liability

A Legal Approach to Liability

What Is Product Liability?

What Is a Product?

The Defect Requirement

The Legal Process

Legal References

References

Chapter 2. FMEA: A General Overview

Critical or Significant Characteristics or Key Indicators

The Four Types of FMEAs

Relationships of FMEA and Other Tools

Who Is Responsible and Controls the FMEA?

Quantitative Techniques

Qualitative Techniques

References

Chapter 3. The Language of the FMEA

Vocabulary of the FMEA

References

Chapter 4. Teams and Team Mechanics of FMEA

What Is a Team?

Why Use a Team?

About Consensus

Team Process Check

Handling of Difficult Individuals

Problem Solving

Planning the Meeting

In-Process Meeting Management

Avoiding Common Meeting Pitfalls

Utilizing the Meeting-Management Guidelines

References

Chapter 5. System FMEA

Step-by-Step System FMEA Analysis

Recommended Team

References

Chapter 6. Design FMEA

Step-by-Step Design FMEA Analysis

Recommended Team

References

Chapter 7. Process FMEA

Step-by-Step Process FMEA Analysis

Recommended Team

References

Chapter 8. Service FMEA

Step-by-Step Service FMEA Analysis

Recommended Team

References

Chapter 9. Machine FMEA

Summary Steps of Conducting the FMEA

References

Chapter 10. FMEA and the Electromechanical Industry

Uses of FMEA

Limitations of FMEA

The Principles of FMEA

Information Necessary to Perform the FMEA

References

Chapter 11. FMEA and Computers: Hardware and Software

A System Approach to Implementation

References

Chapter 12. FMEA and the Semiconductor Industry

References

Chapter 13. FMEA and the Medical Device Industry

References

Chapter 14. FMEA and the Automotive Industry

Definition of FMEA

The FMEA Form

Special Automotive Characteristics

Driving the Action Plan

Getting the Most from FMEA

After the FMEA

References

Chapter 15. FMEA and ISO 9000

References

Chapter 16. Six Sigma and FMEA—Design Review

General

Quality System Assessment (QSA)—Product Development (PD)

Applicability and Scope

Design Review Fundamentals

Design Review Operation

QSA Scoring Guidelines

References

Chapter 17. FMEA and Robustness

References

Chapter 18. An Overview of Some Typical Tools Used in FMEA 391

Tools/Methodologies

Forecasting Rules of Thumb

Epilogue

Glossary

Selected Bibliography

Appendix A. Formulae

Appendix B. Sample Checklist for Design Review

Appendix C. Active Verbs and Nouns Used for Function

Appendix D. FMEA Samples

Appendix E. FMEA Forms

Appendix F. Guidelines for RPN Calculations and Different Scales

Appendix G. Guidelines for Designing the Reasonably Safe Product

Appendix H. Linkages of FMEA

Appendix I. Example of a Concern Resolution, a Block (Boundary) Diagram, a Function Tree, and a P-Diagram for a Spark Plug

List of FMEA Samples Found in Appendix D

All samples are real and represent a variety of different industries. Due to their proprietary nature, changes were made to eliminate company identification. Some of the FMEAs are still being developed and do not have all the columns filled or are only partly presented.

System FMEA

Example 1. Sample of a generic system FMEA

Example 2. Fidd Quad LSD

Design FMEA

Example 3. Throttle body machine

Example 4. Package/layout

Example 5. Armature

Product Design and Development FMEA

Example 6. Cooling fan assembly

Process FMEA

Example 7. Nitride etch

Example 8. Slit base laminate

Example 9. GDS assembly

Service FMEA

Example 10. Complaint diagnosis

FTA Development

Example 11. FTA development of an air pumping system

Machine FMEA

Example 12. Machine FMEA: modular oven

List of Figures

I.1. Loss control sequence

I.2. Pressures leading to overall perception of risks

2.1. FMEA interrelationships

2.2. The road map of product engineering and FMEA

2.3. Evolution of design

2.4. An alternate FMEA construction

2.5. Different distributions

2.6. Types of FMEAs

2.7. Fault tree gate symbols

2.8. Fault tree event symbols

2.9. FTA and FMEA (possible specific failures)

2.10. FTA for engine (incomplete)

2.11. Block diagrams and logic diagrams

2.12. Schematic diagram

2.13. Reliability functional diagram

2.14. Sketch layout diagram

2.15. An example of a typical control plan

2.16. A different format of a control plan

2.17. QFD—the impetus for planning

2.18. The four phases of QFD

2.19. The production planning matrix

2.20. Cowboy after OSHA

3.1. Levels of failure modes

4.1. Teams and great expectations

5.1. Relationship of system, design, and process FMEA

5.2. Relationship of system, assembly, and part FMEA

5.3. Relationship of system, design, and service FMEA

5.4. A form for system FMEA

5.5. Reliability bathtub curve

5.6. Cases of no-failure performance

5.7. Catastrophic and degradation failures and their effects on output

6.1. A form for design FMEA

6.2. Function evaluation worksheet

6.3. Part deployment

6.4. Cost effectiveness

7.1. Relationship of a process FMEA in an iteration mode of failure identification

7.2. A form for process FMEA

8.1. The relationship of a service FMEA in an iteration mode of failure identification

8.2. A form for service FMEA

9.1. An example of a machinery FMEA

10.1. Criteria for a product

10.2. Cause-and-effect diagram

11.1. Software failures

11.2. IBM’s 12 biggest PC blunders

11.3. Software structure overview for FMEA application

14.1. Early planning through FMEA and quality lever

14.2. The Kano model

14.3. Scope for DFMEA—braking system

14.4. Scope for PFMEA—printed circuit board screen printing process

14.5. A typical FMEA header

14.6. A typical FMEA body

14.7. Function tree process

14.8. Function tree for a ball point pen

14.9. A typical format for the failure mode analysis

14.10. Failure modes in the FMEA form

14.11. Effects positioned in FMEA form

14.12. Causes and their ratings placed on the FMEA form

14.13. Current controls and their rating placed on the FMEA form

14.14. RPN placed on the FMEA form

14.15. Action plans and results analysis

14.16. Record final outcomes in the action plan and action results

14.17. FMEA to control plan

14.18. The learning stages

14.19. Example: pen assembly process

17.1. A typical boundary structure

17.2. A typical interface matrix

17.3. A typical P-diagram format

17.4. A typical characteristic matrix

A.1. Reliability block diagrams

A.2. Development of block diagrams from system to units

B.1. Typical process flow diagram of system development process

B.2. Process flow diagram of typical considerations of a new product to be produced

B.3. Design FMEA procedure

B.4. Process FMEA interrelationships

B.5. Reliability growth in terms of contract milestones

E.1. A generic FMEA form

E.2. A generic FMEA form

E.3. A generic FMEA form

E.4. A design FMEA form

E.5. A design FMEA form

E.6. A process FMEA form

E.7. A design FMEA form

E.8. A process FMEA form

E.9. A process FMEA form

E.10. The recommended standard design form for the automotive industry

E.11. The recommended standard process form for the automotive industry

E.12. A design FMECA form

E.13. A process FMECA form

E.14. An FMEA and causal analysis form

E.15. An FMEA and value engineering analysis form

H.1. Process flow diagram for a coffee chopper

H.2. A basic control system

H.3. Boundary diagram of the mounted enclosure assembly

H.4. Wall mounted enclosure P-diagram

H.5. Wall mounted enclosure interface matrix

H.6. Wall mounted enclosure—design

H.7. Example of a process FMEA

I.1. Block diagram

I.2. Function tree

I.3. P-diagram

List of Tables

I.1. Quality today

2.1. Criteria for selecting ratings

5.1. Severity guideline for system FMEA (1–10 qualitative scale)

5.2. Occurrence guideline for system FMEA (1–10 qualitative scale)

5.3. Detection guideline for system FMEA (1–10 qualitative scale)

6.1. Severity guideline for design FMEA (1–10 qualitative scale)

6.2. Occurrence guideline for design FMEA (1–10 qualitative scale)

6.3. Detection guideline for design FMEA (1–10 qualitative scale)

7.1. Severity process and/or service guidelines

7.2. Occurrence process and/or service guidelines

7.3. Detection process and/or service guidelines

9.1. Machinery guidelines for severity, occurrence, and detection

10.1. Design FMEA

10.2. Process FMEA

14.1. A typical Pugh matrix

16.1. Roles and responsibilities—design review process

16.2. Scoring guidelines

16.3. Requirements and criteria for the definition stage

16.4. Requirements and criteria for derivation of specification

16.5. Requirements and criteria for system architecture definition

16.6. Requirements and criteria for selection of the product or process concept

16.7. Requirements and criteria for concurrent product and process design

16.8. Requirements and criteria for preventing failure modes and decrease variability

16.9. Requirements and criteria for optimizing function in the presence of noise

16.10. Requirements and criteria for tolerance design

16.11. Requirements and criteria for finalizing process/control plans

16.12. Requirements and criteria for design verification

16.13. Requirements and criteria for design/manufacturing confirmation

16.14. Requirements and criteria for launch/mass production confirmation

16.15. Requirements and criteria for forming a team

16.16. Requirements and criteria for establishing a program information center

16.17. Requirements and criteria for establishing corporate knowledge

16.18. A summary score sheet with some typical working documents

17.1. Summary of robustness

A.1. Equations for the calculation of the MTBF in series

A.2. Equations for the calculation of the MTTF in parallel

A.3. Equations for the reliability and mean life of a complex system with cyclical units

B.1. Sequence of FMECA activities and responsibilities

B.2. A typical design review schedule in relationship to process phases

C.1. Verbs and nouns for system/design FMEA

C.2. Verbs and nouns for process/service FMEA

C.3. Typical functions used in FMEA

F.1. Numerical guidelines for 1–5 scale in occurrence, detection, and severity

F.2. Word description for 1–5 scale for design FMEA

F.3. Word description for 1–5 scale for process FMEA

F.4. Word description for 1–5 scale for service FMEA

F.5. Severity guideline for process FMEA (1–10 qualitative scale)

F.6. Occurrence guideline for process FMEA (1–10 qualitative scale)

F.7. Detection guideline for process FMEA (1–10 qualitative scale)

F.8. Severity guideline for service FMEA (1–10 qualitative scale)

F.9. Occurrence guideline for service FMEA (1–10 qualitative scale)

F.10. Detection guideline for service FMEA (1–10 qualitative scale)

I.1. Concern resolution

Preface

Change rarely comes in the form of a whirlwind, despite the currently popular notion to the contrary. Change is not creative destruction, like we’ve been told. Change that expects us to throw out everything we were and start over isn’t change at all, but a convulsion. A hiccup. The Internet did not change everything. Broadband did not change everything. September 11th did not change everything. Nor did Enron, WorldCom, or any other company. Nor will tomorrow’s horror, tomorrow’s amazing breakthrough, or tomorrow’s scandal.

If you follow the cataclysmic theory of change, you will reap a whirlwind indeed. There is a different theory of change that no one talks about, but is much more significant for the wise professional. In the coastlines of any country, state, or territory one can see it every day. The waves may crash against the rocks, but they are a distraction. The real action is the tide. When the tide changes, huge forces are put in motion that cannot be halted. (If you doubt the power of the tide, look at the suburbs of any fair-sized town anywhere. A piece of farmland on the edge of most towns is worth its weight in gold. And why? Because it’s where the affluent middle class wants to bunk down every night.)

Or consider the change being wrought on health care by boomers. Or the change in our concepts of service or of travel. If you get these change-of-the-tide changes right, you will become very rich. It is that simple. Target got it right, but Kmart didn’t. Disney got it right, but Columbia didn’t. Marriott got it right, but Howard Johnson didn’t. GE got it right, but Westinghouse didn’t. Boeing got it right, but McDonnell Douglass didn’t.

And now you will get it right. Just ignore the wind and waves. Watch the tide. What is the tide? Since the early 1980s, the world of quality has been bombarded with the concept of continual improvement. For most of us, this concept has been focused on prevention as opposed to appraisal. Yet, many companies have chosen to disregard this change as a fad and a passing attitude. As a result, we have seen programs on Statistical Process Control (SPC), Total Quality Management (TQM), Six Sigma, Lean manufacturing, Quality Function Deployment (QFD), and many more come and go, with some effect but nothing really substantial. In other words, we have been treating them as whirlwinds rather than tides.

Since 1995, when the first edition of the Failure Mode and Effect Analysis (FMEA), was published by Quality Press, much has changed. However, the quest for excellence continues to drag for many reasons.

To be sure, I am not trying to diminish the importance of the great efforts that many organizations have implemented in their organizations in reducing failures and improving customer satisfaction. For example, in the automotive industry a 10 percent improvement compared to 2001 has been noted by J. D. Power and Associates. This 10 percent is the largest improvement for the industry since 1997. However, that is still not good enough!

J. D. Power also released data based on 65,000 new vehicle buyers and lessees after the 90 days of ownership and targeted 135 potential problems, that was published in the Wall Street Journal with the following data: Toyota had 107 problems per 100 vehicles; Honda had 113; GM averaged 130. Many such examples do exist in many industries. However, there are many more companies that do suffer many losses due to mistakes that could have been avoided if a thorough FMEA was conducted. Some examples are:

Company: Marrone Pasta Corporation, Carmel, NY.—Bad labeling. (For more information on this case, the reader is encouraged to contact the USDA Meat and Poultry Hotline at 1-800-535-4555.)

Affected products: Pasta Del Mondo chicken ravioli.

Reason: Contains undeclared eggs, which could be dangerous if eaten by someone allergic to eggs.

Number recalled: 3,150 pounds

Company: Candle-lite, Cincinnati, Ohio.—Unsafe design. (For more information on this case the reader is encouraged to contact The Consumer Product Safety Commission.)

Affected products: Ceramic potpourri simmering pots.

Reason: Flames from the tea light candles inside can flare out the side ventilation holes, possibly causing burns.

Number recalled: 80,000

Note: The pots were sold under the Martha Stewart Everyday Brand.

Company: In-Sink-Erator, Racine, Wisconsin.—Defective materials. (For more information on this case the reader is encouraged to contact the Consumer Product Safety Commission.)

Affected products: Half-gallon instant hot water dispensers.

Reason: Water can leak from the metal holding tank, wet insulating material, and cause electrical arcing and heat build-up.

Number recalled: 252,000

Note: Tanks were sold under the brand names In-Sink-Erator, ISE, Steamin’ Hot, Emerson, Dayton, ACE, Kenmore, and Kohler.

Our intent in this edition is to bring the reader up-to-date and to focus on some minor changes, as well as additions, in the process of doing an FMEA. Specifically, we have replaced the ISO chapter with the new information as relates to the ISO 9000:2000, added a new chapter on FMEA and Six Sigma, and a new chapter on machine FMEA. Also, we have added an expanded chapter on the automotive industry and the requirements of the ISO/TS19649. We also have added a chapter on robustness and the linkages of FMEA to boundary diagram, P diagram, interfacing diagram, and the characteristic matrix.

Yet another major change in this addition is the inclusion of a CD to cover all the appendices and added information. We believe that the reader will find it quite helpful. The CD has all the appendices from the first edition but also includes some very current examples of P diagrams, interfacing diagrams, robustness, and a template for an FMEA facilitator to guide him or her through the questioning process. Furthermore, through an example it follows the application of the FMEA methodology from a boundary diagram to a process FMEA.

In addition this edition incorporates:

New definitions from the SAE J1739 September 2000 revision

Recognition that environment and attribute FMEA may be an option

Updated glossary

As in the first edition, we have tried to make each of the chapters and appendices independent of each other. Therefore, the reader may find some overlap in the discussion of each type of the FMEA. This overlap is by design, as we have tried to demonstrate that the FMEA methodology—no matter where it starts—is a connecting thread. That thread is emphasized through the linkages of the FMEA in Chapter 17 and Appendices H and I with several examples. To be sure, if one does all the steps, they will indeed have an excellent design—but not a perfect design, as perfection belongs in the domain of God. On the other hand, if all the steps are not followed then there is a possibility that marginal success may follow.

A final point. Figure 2.6 shows the relationship of the four types of the FMEA. However, Chapter 9 is devoted to machine FMEA, and in Chapter 14 we make references to environmental and attribute FMEA. This is not an oversight on our part, rather the fundamental issues of machine, environmental, and attribute FMEA is nothing more that a variation of design FMEA. Consequently, they do not appear on Figure 2.6. There is no contradiction and there should not be any confusion about it.

Acknowledgments

In any endeavor, more than one person is responsible for carrying the task to completion. The efforts resulting in this book are no exception. Many people have contributed to the production of this book, either directly or indirectly.

As in the first edition, I want to thank:

Prentice Hall for giving me permission to use some of the material from Reliability Engineering Handbook (Volumes 1 and 2) by Dimitri Kececioglu, and Logistics Engineering and Management, 3rd edition, by Benjamin S. Blanchard.

SAE and Dr. Alvin S. Weinstein for giving me permission to use and summarize some of the materials on product liability from the seminar material given by SAE under the title Product Liability and the Engineer, SAE publication #82002.

Shepard’s/McGraw-Hill Inc. for allowing me to use some data from Products Liability: Design and Manufacturing Defects by Lewis Bass.

Mr. D. Lazor and Mr. B. Schwartz Jr. from Ford Motor Company for giving me the opportunity to work on an FMEA; and the corporate quality department at Ford for their permission to use some of the early data on FMEA.

Motorola Company for permitting use of some failures found in the semiconductor industry from Reliability and Quality Handbook, 1992 edition.

The NLN and Jones and Bartlett Publishers for giving me permission to summarize some of the chapters dealing with Law of Reliability from Legal Aspects of Health Care Administration by G. Pozgar.

Mr. H. Cardenas from Texas Instruments for discussing issues and concerns in that industry.

J. Baker from LifeScan Company, Mr. S. Hall from Hewlett-Packard, E. J. Dammeyer from Sandoz Pharmaceuticals, and M. G. Peterson from Ford Motor Company for discussing issues that deal with specific trouble spots in utilizing an FMEA.

Judges J. Kandrevas and T. Chionos and attorney A. Golematis for reviewing and helping in the compilation of the reliability section and the legal references.

ASQ for granting permission for adapting the ISO 9000:2000 clauses to the new chapter.

National Safety Council for permitting us to show the Cowboy after OSHA published in the National Safety News, (1972). Vol. 106, No. 1 by J. N. Devin.

To all the participants of my public seminars over the years, I owe a large thank you for offering suggestions and specific failures, causes, and effects. I have included as many as possible. Without the participants’ comments and input, this book would not have been possible.

I also want to thank Mr. R. Munro and editors of this book for reviewing and offering suggestions for improvement.

Introduction

In the past 100 years or so, the United States has been the envy of the world. This country has been the leader in almost every major innovation people have made. The historical trend has been positive indeed. But what about the future? Should the status quo be retained? Is there anything to worry about? Can the leadership for tomorrow be guaranteed by following past successes?

Yes, indeed the United States wants to be among the leaders; it wants to be better; its citizens want to work smart and be efficient. But with leadership and general betterment comes change—change in behavior and technology. The old ways served workers well but not anymore. The following saying describes the situation best.

If you always do what you always did, you will always get what you always got.

What the United States has is not good enough anymore as world competition increases. The United States must improve or it will be left behind to those who will pursue technological and quality improvements for their products and/or services. Stated in simple terms: This country must change.

As with any transformation, this change brings uncertainty and risk. The recognition that all well-managed companies are interested in preventing or at least minimizing risk in their operations is the concept of risk management analysis. Bass (1986) showed this concern of risk in Figure I.1. The requirements for performing such analysis may be extensive and demanding. The elimination, control, or reduction of risk is a total commitment by the entire organization, and it is more often than not the responsibility of the engineering department.

Figure I.1 Loss control sequence.

Adopted from Bass, L. 1986. Products Liability: Design and Manufacturing Defects. Colorado Springs, Colo.: Shepard's/McGraw-Hill. Used with Permission.

The focus of identifying and/or analyzing the risks may be due to a variety of reasons, such as customer requests, continual improvement philosophy, and competition. This is shown in Figure I.2.

Figure I.2 Pressures leading to overall perception of risks.

The risk analysis has a fundamental purpose of answering the following two questions (Stamatis 1989, 1991, 1992):

What can go wrong?

If something does go wrong, what is the probability of it happening, and what is (are) the consequence(s)?

To answer these questions, problems used to be examined. Of course, by focusing on problems it was assumed that somebody was to blame, and action was taken.

Today, that paradigm has changed. The focus is on prevention. A comparison of the shift in thinking follows.

This book addresses the issue of risk elimination by focusing on the failure mode and effect analysis (FMEA). FMEA is a specific methodology to evaluate a system, design, process, or service for possible ways in which failures (problems, errors, risks, concerns) can occur.

For each of the failures identified (whether known or potential), an estimate is made of its occurrence, severity, and detection. At that point, an evaluation is made of the necessary action to be taken, planned, or ignored. The emphasis is to minimize the probability of failure or to minimize the effect of failure.

This simple but straightforward approach can be technical (quantitative) or nontechnical (qualitative). In either case, the focus is on the risk one is willing to take. By definition, the FMEA becomes a systematic technique using engineering knowledge, reliability, and organizational development techniques; in other words, teams to optimize the system, design, process, product, and/or service (Stamatis 1991a).

The complication of the approach always depends on the complexity of the problem as defined by the following (Juran and Gryna 1980):

Safety—Injury is the most serious of all failure effects. In fact, in some cases it is of unquestionable priority. At this point it must be handled either with a hazard analysis and/or failure mode and critical analysis (FMCA).

Effects on downtime—What problems are affecting yield? How is that effect being monitored? What type of testing is available? Is the testing appropriate? How are repairs made? Are the repairs appropriate? Is preventive maintenance part of quality planning? Can the repairs be made while the machine is off-line or should they be made while the machine is operating? Is corrective action actively pursued?

Repair planning—Repair time; maintainability; repair costs; repair tools; recommendation(s) for changes in specifications in fit, form, and function. The Shingo (Poka-Yoke) approach, design of experiments (DOE), or design for manufacturability (DFM) may be considered for this problem.

Access—What hardware items must be removed to gain access to the failed component? This area will be of great importance as environmental laws and regulations are introduced and/or changed to reflect world conditions for disassembly, removal, and disposal.

To carry this methodology to its proper conclusion there are at least four prerequisites that must be understood and followed.

All problems are not the same. Not all problems are equally important. This is perhaps the most fundamental concept in the entire FMEA methodology. Unless a priority of problems (as a concept) is recognized, workers are likely to be contenders for chasing fires. They will respond to the loudest request and/or the problem of the moment. (In other words, they will manage by emergency.) In no uncertain terms, workers must recognize and believe in the principle of the vital few as opposed to the trivial many (Pareto principle). The FMEA will help identify this priority.

The customer must be known. Before one undertakes the responsibitity of conducting an FMEA it is imperative that the customer be defined. Traditionally, the definition of customer is thought of as the end user. That, however, may be a simplified approach; indeed a definition that may not apply to the problem. A customer also may be viewed as the subsequent or downstream operation as well as a service operation (Ford 1992). In some cases, the customer may be the operation itself.

This is important because when using the term customer from an FMEA perspective, the definition plays a major role in addressing problems and their solutions. For example, as a general rule, in the design FMEA the customer is viewed as the end user, but in the process FMEA the customer is viewed as the next operation in line.

This next operation may be the end user, but it does not have to be. After the customer has been defined as external, intermediate, internal, or self, it cannot be changed (at least for the problem at hand) without some surprise ramifications. Those ramifications will affect the definition and consequences of the problem.

The function must be known. It is imperative that the function, purpose, and objective of what is to be accomplished be known. Otherwise the result is wasting time, and the effort is focused on redefining the problem based on situations. If necessary, the extra time must be taken to ensure that everyone concerned understands the function, purpose, and objective of what is to be accomplished.

One must be prevention oriented. Unless continual improvement is the force that drives the FMEA, the efforts of conducting an FMEA will be static. The FMEA will be conducted only to satisfy customers and/or market requirements to the letter rather than the spirit of the requirements. (Unfortunately, this is a common problem in implementation of an FMEA program). This is a myopic perspective and as such the spirit of improvement will be lost. The emphasis will be on speed—Let us get it done, as soon as possible and move to the next one. Remember, there is a correlation between time and quality. The following diagram shows the relationship.

The moral of the diagram is that it is impossible to have all three factors at the same time. A company must decide which type of product it wants. After the decision is made, it develops that niche in the market. The television commercial for Paul Masson’s wines exemplifies the notion of quality versus time versus price: We will sell no wine before its time.

The push for this continual improvement makes the FMEA a dynamic document, changing as the system, design, process, product, and/or service changes with the intent always to make a better system, design, process, product, and/or service. Therefore, all FMEAs are living documents.

Why Conduct An FMEA?

The propensity of managers and engineers to minimize the risk in a particular system, design, process, and/or service has forced an examination of reliability engineering, not only to minimize the risk, but also to define that risk whenever possible. Some of the forces for defining risks were shown in Figure I.2.

These risks can be measured by reliability engineering and/or statistical analysis. Because of their complexity, however, the FMEA has extracted the basic principles without the technical mathematics. (See Appendix A for specific formulae and techniques.) It also has provided a tool that anybody committed to continual improvement can utilize.

Statistical process control (SPC) is another tool that provides the impetus for implementation of an FMEA, especially for a process and service FMEA. SPC provides information about the process in regard to changes. These changes are called common and special causes. From an FMEA perspective, the common causes may be considered as failures that are the result of inherent failure mechanisms; as such, they can affect the entire population. In this case, the common cause may raise additional questions and/or concerns so that further examination of the system or design may be in order (Denson 1992).

Conversely, special causes are considered as failures that result from part defects and/or manufacturing problems; they can affect a relatively small population. In this case, there is cause for examining the process (Denson 1992).

Customer requisition strongly influences the motivation to perform an FMEA. For example, all major automobile companies in their supplier certification standards even before the international standards (such as, Ford— Q101, General Motors—Targets for Excellence, Chrysler—Pentastar) required an FMEA program for their suppliers (Chrysler 1986; Ford 1992; General Motors 1988). The same is true with other industries (such as semiconductor, computer, government, aerospace, and medical device). Through product liability, courts may also require some substantiation as to what level of reliability products and/or services perform (Bass 1986).

International standards such as the ISO 9000 series may define the program of documentation in design (Stamatis 1992; see also Chapter 13). For example, the product liability directive of the European Commission (EC) 1985 stipulates that manufacturers of a product will be held liable, regardless of fault or negligence, if a person is harmed or an object is damaged by a faulty or defective product. (This includes exporters into the European Union [EU] market.) This liability directive essentially reverses the burden of proof of fault from the injured to the producer. For more details see Chapters 13 and 14. (Hagigh 1992; Kolka, Link, and Scott 1992; Kolka and Scott 1992; Linville 1992). In addition, ISO/TS 16949 Section 7 (2002-03-01) is abundantly clear of the FMEA requirement.

Other benefits of conducting an FMEA include the following:

Helps define the most significant opportunity for achieving fundamental differentiation (Peters 1992). After all, there is only one organization that can distinguish itself as the cheapest in town. The rest have to depend on other attributes.

Improves the quality, reliability, and safety of the products or service. (Table I.1 shows that even 99.9 percent is not good enough in certain situations.)

Table I.1 Quality today.

Helps select alternatives (in system, design, process, and service) with high reliability and high safety potential during the early phases (Blanchard 1986).

Improves the company’s image and competitiveness.

Helps increase customer satisfaction.

Reduces product development time and costs.

Helps select the optimal system design.

Helps determine the redundancy of the system.

Helps identify diagnostic procedures.

Establishes a priority for design improvement actions.

Helps identify critical and or significant characteristics.

Helps in the analysis of new manufacturing and or assembly process.

Helps in the analysis of tasks, sequence, and or service.

Helps establish the forum for defect prevention.

Helps error identification and prevention.

Helps define the corrective action.

Ensures that all conceivable failures and their effects on operational success have been considered.

Lists potential failures and identifies the relative magnitude of their effects.

Provides the basis for the test program during development and final validation of the system, design, process, or service.

Develops early criteria for manufacturing, process, assembly, and service (Kececioglu 1991).

Provides historical documentation for future reference to aid in the analysis of field failures and consideration of design, process, and service changes.

Provides a forum for recommending and tracking risk-reducing actions.

Major technical advances.

Demanding customer requirements.

Intense shareholder pressure.

Global consolidation of alliances.

Continuing price and margin pressures.

Increasing sophistication of customers.

Economic challenges with design innovations/modifications.

The most important reason for conducting an FMEA is the need to improve. To receive all or some of the benefits of an FMEA program, the need to improve must be ingrained in the organization’s culture. If not, the FMEA program will not succeed. Therefore, a successful FMEA is both a company and a supplier requirement for world-class quality. Specifically, any FMEA can help in the following areas:

Superior competitive advantage

Best in class value

Quality performance

Sustainable cost advantage

Flawless launch

Superior organizational capability

Brings best of class design

Breakthrough technology

Moves fast

Superior culture

Can do attitude

Obsesses with continual improvement

Team spirit

Saying no the right way

References

———. 1992. ISO 9000 standards: Are they for real? Technology (Engineering Society of Detroit) (August): 13–17.

———. (2002). ISO/TS 16949. International Automotive Task Force. AIAG Edition.

Bass, L. 1986. Products liability: Design and manufacturing defects. Colorado Springs, CO: Shepard’s/McGraw-Hill.

Blanchard, B. S. 1986. Logistics engineering and management. 3d ed. Englewood Cliffs, NJ: Prentice Hall.

Chrysler Motors. 1986. Design feasibility and reliability assurance. In FMEA Highland Park, MI: Chrysler Motors Engineering Office.

Denson, W. K. 1992. The use of failure mode distributions in reliability analyses. RAC Newsletter (Reliability Analysis Center, a Department of Defense Information Analysis Center) (spring): 1–3.

Ford Motor Company. 1992. FMEA handbook. Dearborn, MI: Ford Motor Company, Engineering Materials and Standards.

General Motors. 1988. FMEA reference manual. Detroit, MI: General Motors Corporation, Reliability and Technology Department.

Hagigh, S. 1992. Obtaining EC product approvals after 1992: What American manufacturers need to know. Business America, 24 February.

Juran, J. M., and F. M. Gryna, Jr. 1980. Quality planning and analysis. New York: McGraw-Hill.

Kececioglu, D. 1991. Reliability engineering handbook, Vols. 1 and 2. Englewood Cliffs, NJ: Prentice Hall.

Kolka, J. W., D. M. Link, and G. G. Scott. 1992. Medical device directives: Certification, quality assurance, and liability. Fairfax, VA: CEEM Information Services.

Kolka, J. W., and G. G. Scott. 1992. Product liability and product safety directives. Fairfax, VA: CEEM Information Services.

Linville, D. 1992. Exporting