The Certified Reliability

Engineer Handbook

Second Edition

Donald W. Benbow and Hugh W. Broome

ASQ Quality Press

Milwaukee, Wisconsin

Table of Contents

CD-ROM Contents ix

List ofFigures and Tables x

Preface xiii

Acknowledgments xiv

Part I Reliability Management

Chapter 1 A. Strategic Management 2

1. Benefits of Reliability Engineering 2

2. Interrelationship of Quality and Reliability 3

3. Role of the Reliability Function in the Organization 5

4. Reliability in Product and Process Development 6

5. Failure Consequence and Liability Management 9

6. Warranty Management 10

7. Customer Needs Assessment 12

8. Supplier Reliability 16

Chapter 2 B. Reliability Program Management 18

1. Terminology 18

2. Elements of a Reliability Program 21

3. Types of Risk 23

4. Product Lifecycle Engineering 25

5. Design Evaluation 30

6. Systems Engineering and Integration 32

Chapter 3 C. Ethics, Safety, and Liability 34

1. Ethical Issues 34

2. Roles and Responsibilities 35

3. System Safety 37

Part II Probability and Statistics for Reliability

Chapter 4 A. Basic Concepts 40

1. Statistical Terms 40

2. Basic Probability Concepts 42

3. Discrete and Continuous Probability Distributions 51

4. Poisson Process Models 62

5. Non-parametric Statistical Methods 63

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6. Sample Size Determination 67

7. Statistical Process Control (SPC) and Process Capability 70

Chapter 5 B. Statistical Inference 81

1. Point Estimates of Parameters 81

2. Statistical Interval Estimates 85

3. Hypothesis Testing (Parametric and Non-Parametric) 98

Part III Reliability in Design and Development

Chapter 6 A. Reliability Design Techniques 118

1. Environmental and Use Factors 118

2. Stress-Strength Analysis 119

3. FMEA and FMECA 120

4. Common Mode Failure Analysis 126

5. Fault Tree Analysis (FTA) and Success Tree Analysis (STA) 126

6. Tolerance and Worst-Case Analyses 130

7. Design of Experiments 132

8. Fault Tolerance 151

9. Reliability Optimization 152

10. Human Factors 153

11. Design for X (DFX) 155

12. Reliability Apportionment (Allocation) Techniques 156

Chapter 7 B. Parts and Materials Management 159

1. Selection, Standardization, and Reuse 159

2. Derating Methods and Principles 161

3. Parts Obsolescence Management 162

4. Establishing Specifications 163

Part IV Reliability Modeling and Predictions

Chapter 8 A. Reliability Modeling 168

1. Sources and Uses of Reliability Data 168

2. Reliability Block Diagrams and Models 170

3. Physics of Failure Models 181

4. Simulation Techniques 182

5. Dynamic Reliability 187

Chapter 9 B. Reliability Predictions 188

1. Part Count Predictions and Part Stress Analysis 188

2. Reliability Prediction Methods 191

Part V Reliability Testing

Chapter 10 A. Reliability Test Planning 194

1. Reliability Test Strategies 194

2. Test Environment 200

Table of Contents vii

Chapter 11 B. Testing During Development 202

1. Accelerated Life Tests (e.g., Single-Stress, Multiple-Stress, SequentialStress, Step-Stress) 202

2. Discovery Testing (e.g., HALT, Margin Tests, Sample Size of 1) 205

3. Reliability Growth Testing (e.g., Test, Analyze, and Fix (TAAF),

Duane) 207

4. Software Testing (e.g., White-Box, Black-Box, Operational Profile,

and Fault Injection) 209

Chapter 12 C. Product Testing 212

1. Qualification/Demonstration Testing (e.g., Sequential Tests, Fixed-

Length Tests) 212

2. Product Reliability Acceptance Testing (PRAT) 217

3. Ongoing Reliability Testing (e.g., Sequential Probability Ratio Test

[SPRT]) 217

4. Stress Screening (e.g., ESS, HASS, Burn-In Tests) 220

5. Attribute Testing (e.g., Binomial, Hypergeometric) 220

6. Degradation (Wear-to-Failure) Testing 224

Part VI Maintainability and Availability

Chapter 13 A. Management Strategies 226

1. Planning 226

2. Maintenance Strategies 228

3. Availability Tradeoffs 230

Chapter 14 B. Maintenance and Testing Analysis 232

1. Preventive Maintenance (PM) Analysis 232

2. Corrective Maintenance Analysis 233

3. Non-destructive Evaluation 234

4. Testability 236

5. Spare Parts Analysis 237

Part VII Data Collection and Use

Chapter 15 A. Data Collection 244

1. Types of Data 244

2. Collection Methods 245

3. Data Management 246

Chapter 16 B. Data Use 249

1. Data Summary and Reporting 249

2. Preventive and Corrective Action 255

3. Measures of Effectiveness 260

Chapter 17 C. Failure Analysis and Correction 264

1. Failure Analysis Methods 264

2. Failure Reporting, Analysis, and Corrective Action System (FRACAS)... 266

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Part VIII Appendices

Appendix A ASQ Certified Reliability Engineer Body of Knowledge 270

Appendix B ASQ Code of Ethics 279

Appendix C Control Limit Formulas 281

Appendix D Constants for Control Charts 282

Appendix E Areas under Standard Normal Curve 283

Appendix F F Distribution F0.i 285

Appendix G F Distribution F„.05 289

Appendix H F Distribution F0.01 293

Appendix I Chi Square Distribution 297

Appendix J Values of the t-Distribution 299

Appendix K Statistical Tolerance Factors for at Least 99 Percent of

the Population 301

Appendix L Critical Values for the Mann-Whitney Test 302

Appendix M Critical Values for Wilcoxon Signed Rank Test 303

Appendix N Poisson Distribution 304

Appendix O Binomial Distribution 306

Appendix P Exponential Distribution 308

Appendix Q Median Ranks 310

Appendix R 312

Glossary 323

References 335Index 337