Quality and Reliability of Technical Systems

Transcription

1 Quality and Reliability of Technical Systems

2 Springer Berlin Heidelberg New York Barcelona Budapest HongKong London Milan Paris Santa Clara Singapore Tokyo

3 A. Birolini Quality and Reliability of Technical Systems Theory, Practice, Management Second Edition with 120 Figures, 55 Tables and, 100 Examples, Springer

4 Prof. Dr. Alessandro Birolini ETH Zurich Swiss Federal Institute of Technology Reliability Laboratory ETH Zentrum, ETZ H Zurich Switzerland ISBN-13: > DOl: / " Cip data applied for Die Deutsche Bibliothek - CIP-Einheitsaufnahme Birolini. Alessandro: Quality and reliability of techical systems: theory. practice, management; with 55 tables and, 100 examples I A. Birolini ed. - Berlin; Heidelberg; New York; Barcelona; Budapest; Hong KOng; Milan; Paris; Santa Clara; Singapore; Tokyo: Springer, 1997 ISBN-I): 9711-)~'"979II5-9 This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilm or in other ways, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer-Verlag. Violations are liable for prosecution act under German Copyright Law. Springer-Verlag Berlin Heidelberg 1994 and 1997 Softcover reprint of the hardcover 2nd edition 1997 The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. Typesetting: Camera-ready by author; Cover design: Struve & Partner, Heidelberg SPIN:I Printed on acid -free paper

5 Preface High reliability, maintainability, and safety are expected from complex equipment and systems. To build these characteristics into an item, failure rate and failure mode analyses have to be performed early in the design and development phase, and be supported by design guidelines for reliability, maintainability, and software quality as well as by extensive design reviews. Before production, qualification tests of prototypes are necessary to ensure that quality and reliability targets have been reached. In the production phase, processes need to be selected and monitored to assure the required quality level. For many systems, availability requirements must also be satisfied. In these cases, stochastic processes can be used to investigate and optimize availability, including logistical support as well. Software often plays a dominant role, asking for specific software quality assurance activites during the design and development phase. This book presents the state of the art in the methods and procedures used for a cost and time effective quality and reliability assurance during the design, development, and production of equipment and systems. It takes into consideration that: 1. Quality and reliability assurance of complex equipment and systems requires that all engineers involved in a project undertake specific activities from the definition to the operating phase, which are performed concurrently to achieve the best performance, quality, and reliability for given cost and time schedule targets, conforming to Total Quality Management (TQM). 2. When designing and developing reliable equipment and systems, theoretical investigations have to be supplemented by practical considerations, especially with respect to dependencies between elements (parts), environmental and internal stresses (thermal, electrical, mechanical, climatic), interfacing of components and materials, protection against Electrostatic Discharge (ESD), Electromagnetic Compatibility (EMC), use of redundancy, etc. Thus, the book covers theory, practice, and management aspects. It addresses the needs of scientists and system oriented engineers (Chapters 2 and 6, Appendices A6 and A7), of engineers in development or production (Chapters 2 to 5, 7, 8 and Appendix A8), and of project and quality assurance managers (Chapter 1 and Appendices Al to A5). The present second edition is a updated and restructured revision of the first edition (1994), and includes present aspects like Total Quality Management, Concurrent Engineering, and Sustainable Development.

6 VI Tools (methods and procedures) are presented in such a way that they can be tailored to cover the needs from very high down to less stringent reliability, maintainability, availability, or safety requirements. Reliability theory, reliability engineering, and hardware quality assurance are carefully considered, in particular with respect to the modeling of repairable systems using Markov and semi-regenerative processes, the investigation of the predicted reliability, the fulfillment of design guidelines, and qualification tests for components and assemblies. The development of approximate expressions for the reliability and availability of complex repairable systems is considered in depth. Basic design rules for software quality assurance are given. Investigation of fault tolerant systems with hardware and software is a rei. new discipline and is confined here to some basic considerations. To improve readability, topics related to management and mathematical foundations are given in Appendices (AI to A9). As a whole, the book has been used many years (first German edition 1985) as a text book for about 120 hour courses spread over three semesters for graduate students at the ETH Zurich. The first of these courses, focusing on Chapters 1, 2, and 5, with an introduction to Chapters 3, 4, 6, 7, and 8 should belong today to the curriculum of every engineering degree, particularly in electrical and mechanical engineering as well as in computer science. Moreover, the book has been used extensively for courses aimed at engineers in industry (often as a three day course). The book is based on over 20 years experience, half of which was gained by the author in industry. Recent results obtained at the Reliability Laboratory (RL) of the Swiss Federal Institute of Technology (ETH) Zurich have been integrated in Chapters 3, 5, 6, and 8. Many friends have improved the content of this book by commenting on some sections and chapters. To all of them and to the Springer Verlag, I would like to express my best thanks. Zurich, April 1997 Alessandro Birolini

7 Contents 1 Basic Concepts, Quality and Reliability Assurance of Complex Equipment and Systems 1.1 Introduction Basic Concepts Reliability Failure Failure Rate Maintenance, Maintainability Logistical Support Availability Safety, Risk, and Risk Acceptance Quality Cost and System Effectiveness Product Liability Historical Development Quality and Reliability Assurance Tasks for Complex Equipment and Systems Basic Quality and Reliability Assurance Rules Elements of a Total Quality Management System Quality and Reliability Assurance Handbook Motivation and Training Reliability Analysis During the Design Phase Introduction Predicted Reliability of Equipment and Systems with Simple Structures Required Function Reliability Block Diagram Operating Conditions at Component Level, Stress Factors Failure Rate of Electronic Components Reliability of One-Item Structures Reliability of Series-Parallel Structures Items without Redundancy Concept of Redundancy Parallel Models SerieslParailel Structures Majority Redundancy Part Count Method Reliability of Systems with Complex Structures Key Item Method Bridge Structures ReI. Block Diagram in which Elements Appear More than Once Successful Path Method

8 vm Contents State Space Method Boolean Function Method Parallel Models with Constant Failure Rates and Load Sharing Elements With More Than One Failure Mode Fault Tolerant Structures. 2.4 Reliability Allocation. 2.5 Mechanical Reliability Failure Mode Analysis Reliability Aspects in Design Reviews Qualification Tests for Components and Assemblies. 3.1 Selection Criteria for Electronic Components Environment Performance Parameters Technology Manufacturing Quality Long-Term Behavior of Performance Parameters Reliability Qualification Tests for Complex Electronic Components Electrical Test of Complex ICs Characterization of Complex ICs Environmental and Special Tests of Complex ICs Reliability Tests Failure Modes, Failure Mech., and Failure Analysis of Electronic Components Failure Modes of Electronic Components Failure Mechanisms of Electronic Components Failure Analysis of Electronic Components Qualification Tests for Electronic Assemblies Maintainability Analysis Maintenance, Maintainability 4.2 Maintenance Concept Fault Detection and Isolation Equipment and System Partitioning User Documentation Training of Operating and Maintenance Personnel User Logistical Support Maintainability Aspects in Design Reviews. 4.4 Predicted Maintainability Calculation of MITRS' Calculation of MITPMS ' Basic Models for Spare Part Provisioning Centralized Logistical Support, Nonrepairable Spare Parts Decentralized Logistical Support, Nonrepairable Spare Parts Repairable Spare Parts Cost Considerations

9 Contents IX 5 Design Guidelines for Reliability, Maintainability, and Software Quality Design Guidelines for Reliability Derating Cooling Moisture Electromagnetic Compatibility, ESD Protection Components and Assemblies Component Selection Component Use PCB and Assembly Design PCB and Assembly Manufacturing Storage and Transportation Particular Guidelines for IC Design and Manufacturing. 5.2 Design Guidelines for Maintainability General Guidelines Testability Accessibility, Exchangeability Operation, Adjustment Design Guidelines for Software Quality Guidelines for Software Defect Prevention Configuration Management Guidelines for Software Testing Software Quality Growth Models Reliability and Availability of Repairable Systems Introduction and General Assumptions One-Item Structure One-Item Structure New at Time t = O Reliability Function Point Availability Average Availability Interval Reliability Special Kinds of Availability One-Item Structure New at Time t = 0 and with Constant Failure Rate A One-Item Structure with Arbitrary Initial Conditions at Time t = Asymptotic Behavior Steady-State Behavior Systems without Redundancy Series Structure with Constant Failure and Repair Rates Series Structure with Constant Failure and Arbitrary Repair Rates Series Structure with Arbitrary Failure and Repair Rates l-out-of-2 Redundancy l-out-of-2 Redundancy with Constant Failure and Repair Rates l-out-of-2 Redundancy with Constant Failure and Arbitrary Repair Rates l-out-of-2 Redundancy with Const. Failure Rate only in the Reserve State k-out-of-n Redundancy k-out-of-n Warm Redundancy Constant Failure and Repair Rates k-out-of-n Active Redundancy with Const. Failure and Arbitrary Repair Rates Simple SerieslParallel Structures

10 x Contents 6.7 Approximate Expressions for Large SerieslParallel Structures Introduction Application to a Practical Example Systems with Complex Structure General Considerations Computer Aided Reliability and Availability Prediction Influence of Imperfect Switching Influence of Preventive Maintenance One-item Repairable Structure l-out-of-2 Active Redundancy with Hidden Failures in one Element Statistical Quality Control and Reliability Tests Statistical Quality Control Estimation of a Defective Probability p Simple Two-sided Sampling Plans for the Demonstration of a Probability p Simple Two-sided Sampling Plans Sequential Tests One-sided Sampling Plans for the Demonstration of a Probability p Statistical Reliability Tests Estimation and Demonstration of a Reliability or Availability Value Estimation and Demonstration of a Constant Failure Rate A. or MTBF = 1/ A Estimation of a constant Failure Rate A. or of MTBF = 11 A Simple Two-sided Test for the Demonstration of A. or MTBF = 1/ A Simple One-sided Test for the Demonstration of A. or MTBF = 1/ A Statistical Maintainability Tests Estimation of an MITR Demonstration of an MITR. 7.4 Accelerated Testing Goodness-of-fit Tests Kolmogorov-Smimov Test Chi-square Test Quality and Reliability Assurance During the Production Phase. 8.1 Basic Activities Testing and Screening of Electronic Components Testing of Electronic Components Screening of Electronic Components Testing and Screening of Electronic Assemblies. 8.4 Test and Screening Strategies, Economic Aspects Basic Considerations Quality Cost Optimization Procedure to handle first deliveries. 8.5 Reliability Growth

11 Contents XI At Terms and Definitions A2 Quality and Reliability Standards..311 A2.1 Introduction.' A2.2 Requirements in the Industrial Field. A2.3 Requirements in the Aerospace, Defense, and Nuclear Fields A3 Definition and Realization of Quality and Reliability Requirements..315 A3.1 Definition of Quality and Reliability Requirements... A3.2 Realization of Quality and Reliabilty Requirements... A3.3 Elements of a Quality and Reliability Assurance Program A3.3.1 Project Organization, Planning, and Scheduling.322 A3.3.2 Quality and Reliability Requirements A3.3.3 Reliability and Safety Analyses A3.3.4 Selection and Qualific. of Components, Materials, and Manuf. Processes. 324 A3.3.5 Configuration Management A3.3.6 Quality Tests A3.3.7 Quality Data Reporting System A4 Checklists for Design Reviews A4.! System Design Review A4.2 Preliminary Design Reviews (Assembly Level) A4.3 Critical Design Review (System Level) AS Requirements for Quality Data Reporting Systems..334 A6 Basic Probability Theory A6.! Field of Events. A6.2 Concept of Probability A6.3 Conditional Probability, Independence. A6.4 Fundamental Rules of Probability Theory A6.4.! Addition Theorem for Mutually Exclusive Events. A6.4.2 Multiplication Theorem for Two Independent Events A6.4.3 Multiplication Theorem for Arbitrary Events. A6.4.4 Addition Theorem for Arbitrary Events. A6.4.5 Theorem of Total Probability. A6.5 Random Variables, Distribution Functions A6.6 Numerical Parameters of Random Variables A6.6.! Expected Value (Mean). A6.6.2 Variance. A6.6.3 Modal Value, Quantile, Median. A6.7 Multidimensional Random Variables, Conditional Distributions. A6.8 Numerical Parameters of Random Vectors A6.8.1 Covariance Matrix, Correlation Coefficient. A6.8.2 Further Properties of Expected Value and Variance. A6.9 Distribution of the Sum ofindep. Positive Random Variables and of 'trnin' 'tmax !

12 XII Contents A6.10 A6.11 Distribution Functions used in Reliability Analyses A Exponential Distribution A6.1O.2 Weibull Distribution A Gamma Distribution, Erlangian Distribution, and 'X} -Distribution. A Normal Distribution.. A6.1O.5 Lognormal Distribution. A6.1O.6 Uniform Distribution. A Binomial Distribution. A6.10.S Poisson Distribution. A Geometric Distribution A6.1O.1O Hypergeometric Distribution. Limit Theorems A Law of Large Numbers A Central Limit Theorem S S.37S.379.3S0 A7 Basic Stochastic Process Theory A 7.1 Introduction A7.2 Renewal Processes.... A7.2.1 Renewal Function, Renewal Density. A7.2.2 Recurrence Times..... A7.2.3 Asymptotic Behavior.... A7.2.4 Stationary Renewal Processes A7.2.5 Poisson Processes.. A 7.3 Alternating Renewal Processes.....3S4.3S4.3S7.3S S A7.4 Regenerative Processes A7.5 Markov Processes with Finitely Many States.404 A7.5.1 Markov Chains with Finitely Many States..404 A7.5.2 Markov Processes with Finitely Many States.406 A7.5.3 State Probabilities and Sojourn Times in a Given Class of States..415 A Method of Differential Equations A Method ofintegral Equations A Stationary State and Asymptotic Behavior.420 A7.5.4 Birth and Death Process A7.6 Semi-Markov Processes with Finitely Many States. A 7.7 Semi-regenerative Processes..... A7.S Nonregenerative Stochastic Processes. AS Basic Mathematical Statistics..'.... AS.l Empirical Methods AS.l.l Empirical Distribution Function. AS.l.2 Empirical Moments and Quantiles. AS.1.3 Further Applications of the Empirical Distribution Function AS.2 Parameter Estimation AS.2.1 Point Estimation AS.2.2 Interval Estimation AS Estimation of an Unknown Probability p. 44S AS Estimation of the Paramo A. of an Exp. Distribution for Fixed T. 452 AS Estimation of the Paramo A. of an Exp. Distribution for Fixed n. 453

13 Contents XIII AS.3 Testing Statistical Hypotheses AS.3.1 Testing an Unknown Probability p..... AS.3.l.1 Simple Two-sided Sampling Plan. AS Sequential Test AS Simple One-sided Sampling Plan. AS.3.2 Goodness-of-fit Tests for Completely Defined FO(t) AS.3.3 Goodness-of-fit Tests for FO(t) with Unknown Parameters. A9 Tables and Charts A9.1 Standard Normal Distribution A9.2 X2-Distribution (Chi-Square Distribution). A9.3 t-distribution (Student distribution)... A9.4 F Distribution (Fischer distribution)... A9.5 Table for the Kolmogorov-Smirnov Test. A9.6 Gamma function.. A9.7 Laplace Transform.... A9.S Probability Charts A9.S.1 Lognormal Probability Chart. A9.S.2 Weibull Probability Chart A9.S.3 Normal Probability Chart Acronyms References Index S S