Reliability Engineering

Preface xv 1 Reliability Engineering in the Twenty-First Century 1 1.1 What Is Quality? 1 1.2 What Is Reliability? 2 1.3 Quality, Customer Satisfaction, and System Effectiveness 6 1.4 Performance, Quality, and Reliability 7 1.5 Reliability and the System Life Cycle 8 1.6 Consequences of Failure 12 1.7 Suppliers and Customers 16 1.8 Summary 16 Problems 17 2 Reliability Concepts 19 2.1 Basic Reliability Concepts 19 2.2 Hazard Rate 26 2.3 Percentiles Product Life 33 2.4 Moments of Time to Failure 35 2.5 Summary 39 Problems 40 3 Probability and Life Distributions for Reliability Analysis 45 3.1 Discrete Distributions 45 3.2 Continuous Distributions 51 3.3 Probability Plots 77 3.4 Summary 83 Problems 84 4 Design for Six Sigma 89 4.1 What Is Six Sigma? 89 4.2 Why Six Sigma? 90 4.3 How Is Six Sigma Implemented? 91 4.4 Optimization Problems in the Six Sigma Process 98 4.5 Design for Six Sigma 103 4.6 Summary 108 Problems 108 5 Product Development 111 5.1 Product Requirements and Constraints 112 5.2 Product Life Cycle Conditions 113 5.3 Reliability Capability 114 5.4 Parts and Materials Selection 114 5.5 Human Factors and Reliability 115 5.6 Deductive versus Inductive Methods 117 5.7 Failure Modes, Effects, and Criticality Analysis 117 5.8 Fault Tree Analysis 119 5.9 Physics of Failure 128 5.10 Design Review 131 5.11 Qualification 132 5.12 Manufacture and Assembly 134 5.13 Analysis, Product Failure, and Root Causes 137 5.14 Summary 138 Problems 138 6 Product Requirements and Constraints 141 6.1 Defi ning Requirements 141 6.2 Responsibilities of the Supply Chain 142 6.3 The Requirements Document 144 6.4 Specifi cations 144 6.5 Requirements Tracking 146 6.6 Summary 147 Problems 147 7 Life-Cycle Conditions 149 7.1 Defining the Life-Cycle Profile 149 7.2 Life-Cycle Events 150 7.3 Loads and Their Effects 152 7.4 Considerations and Recommendations for LCP Development 160 7.5 Methods for Estimating Life-Cycle Loads 165 7.6 Summary 166 Problems 167 8 Reliability Capability 169 8.1 Capability Maturity Models 169 8.2 Key Reliability Practices 170 8.3 Summary 175 Problems 175 9 Parts Selection and Management 177 9.1 Part Assessment Process 177 9.2 Parts Management 185 9.3 Risk Management 188 9.4 Summary 190 Problems 191 10 Failure Modes, Mechanisms, and Effects Analysis 193 10.1 Development of FMMEA 193 10.2 Failure Modes, Mechanisms, and Effects Analysis 195 10.3 Case Study 201 10.4 Summary 205 Problems 206 11 Probabilistic Design for Reliability and the Factor of Safety 207 11.1 Design for Reliability 207 11.2 Design of a Tension Element 208 11.3 Reliability Models for Probabilistic Design 209 11.4 Example of Probabilistic Design and Design for a Reliability Target 211 11.5 Relationship between Reliability, Factor of Safety, and Variability 212 11.6 Functions of Random Variables 215 11.7 Steps for Probabilistic Design 219 11.8 Summary 219 Problems 220 12 Derating and Uprating 223 12.1 Part Ratings 223 12.2 Derating 225 12.3 Uprating 239 12.4 Summary 245 Problems 246 13 Reliability Estimation Techniques 247 13.1 Tests during the Product Life Cycle 247 13.2 Reliability Estimation 249 13.3 Product Qualifi cation and Testing 250 13.4 Case Study: System-in-Package Drop Test Qualifi cation 263 13.5 Basic Statistical Concepts 276 13.6 Confi dence Interval for Normal Distribution 279 13.7 Confidence Intervals for Proportions 282 13.8 Reliability Estimation and Confidence Limits for Success-Failure Testing 283 13.9 Reliability Estimation and Confidence Limits for Exponential Distribution 287 13.10 Summary 292 Problems 292 14 Process Control and Process Capability 295 14.1 Process Control System 295 14.2 Control Charts 299 14.3 Benefi ts of Control Charts 316 14.4 Average Outgoing Quality 317 14.5 Advanced Control Charts 323 14.6 Summary 325 Problems 326 15 Product Screening and Burn-In Strategies 331 15.1 Burn-In Data Observations 332 15.2 Discussion of Burn-In Data 333 15.3 Higher Field Reliability without Screening 334 15.4 Best Practices 335 15.5 Summary 336 Problems 337 16 Analyzing Product Failures and Root Causes 339 16.1 Root-Cause Analysis Processes 341 16.2 No-Fault-Found 351 16.3 Summary 373 Problems 374 17 System Reliability Modeling 375 17.1 Reliability Block Diagram 375 17.2 Series System 376 17.3 Products with Redundancy 381 17.4 Complex System Reliability 393 17.5 Summary 401 Problems 402 18 Health Monitoring and Prognostics 409 18.1 Conceptual Model for Prognostics 410 18.2 Reliability and Prognostics 412 18.3 PHM for Electronics 414 18.4 PHM Concepts and Methods 417 18.5 Monitoring and Reasoning of Failure Precursors 420 18.6 Implementation of PHM in a System of Systems 429 18.7 Summary 431 Problems 431 19 Warranty Analysis 433 19.1 Product Warranties 434 19.2 Warranty Return Information 435 19.3 Warranty Policies 436 19.4 Warranty and Reliability 437 19.5 Warranty Cost Analysis 439 19.6 Warranty and Reliability Management 448 19.7 Summary 449 Problems 449 Appendix A: Some Useful Integrals 451 Appendix B: Table for Gamma Function 453 Appendix C: Table for Cumulative Standard Normal Distribution 455 Appendix D: Values for the Percentage Points talpha,nu of the t-Distribution 457 Appendix E: Percentage Points chi2alpha ,nu of the Chi-Square Distribution 461 Appendix F: Percentage Points for the F-Distribution 467 Bibliography 473 Index 487