Reliability Engineering

396 Pages·1993·10.1 MB·English

by  K. K. Aggarwal (auth.)

RELIABILITY ENGINEERING
TOPICS IN SAFETY, RELIABILITY AND QUALITY
VOLUME 3
Editor
A.Z. Keller, Department of Industrial Technology and Management,
University of Bradford, U.K.
Editorial Advisory board
P. Sander, Technical University of Eindhoven, The Netherlands
D.C. Barrie, Lakehead University, Ontario, Canada
R. Leitch, Royal Military College of Science (Cranfield), Shriverham, U.K.
Aims and Scope. Fundamental questions which are being asked these days of all
products, processes and services with ever increasing frequency are:
How safe?
How reliable?
How good is the quality?
In practice none of the three topics can be considered in isolation as they often
interact in subtle and complex fashions. The major objective of the series is to
cover the spectrum of disciplines required to deal with safety, reliability and
quality. The texts will be of a level generally suitable for final year, M.Sc and Ph.D
students, researchers in the above fields, practitioners, engineers, consultants and
others concerned with safety, reliability and quality.
In addition to fundamental texts, authoritative 'state of the art' texts on topics of
current interest will be specifically commissioned for inclusion in the series.
The special emphasis which will be placed on all texts will be, readability, clarity,
relevance and applicability.
The titles published in this series are listed at the end of this volume.
Reliability Engineering
by
K. K. AGGARWAL
Centre for Excellence in Reliability Engineering.
Regional Engineering College.
Kurukshetra. India
SPRINGER-SCIENCE+BUSINESS MEDIA, B.V.
Library of Congress Cataloging-in-Publication Data
Aggarwa 1. K. K.
Re1labl1lty englneerlng I K.K. Aggarwa1.
p. cm. -- (Toplcs In safety. re1 labl 11ty. and qua1lty v. 3)
Inc1udes blb1lographlca1 references (p. ) and Index.
ISBN 978-94-010-4852-1 ISBN 978-94-011-1928-3 (eBook)
DOI 10.1007/978-94-011-1928-3
1. Re1labl1lty (Englneerlng> I. Tlt1e. II. Serles.
TA168.A33 1993
620' .00452--dc20 93-33130
ISBN 978-94-010-4852-1
Printed an acid-free paper
AII Rights Reserved
© 1993 Springer Science+Business Media Dordrecht
Originally published by Kluwer Academic Publishers in 1993
Softcover reprint of the hardcover 1s t edition 1993
No part of the material protected by this copyright notice may be reproduced or
utilized in any form or by any means, electronic or mechanical,
including photocopying, recording or by any information storage and
retrieval system, without written permission from the copyright owner.
CONTENTS
Preface ix
Chapter 1 RELIABILITY FUNDAMENTALS 1
1.1 Introduction 1
1.2 Need for Reliability Engineering 2
1.3 Definition 4
1.4 Causes of Failures 7
1.5 Catastrophic Failures and Degradation Failures 9
1.6 Characteristic Types of Failures 11
1.7 Useful Life of Components 13
1.8 The Exponential Case of Chance Failures 15
1.9 Reliability Measures 19
1.10 Failure Data Analysis 25
Chapter 2 RELIABILITY MATHEMATICS 30
2.1 Fundamentals of Set Theory 30
2.2 Probability Theory 32
2.3 Random Variables 36
2.4 Discrete Distributions 37
2.5 Continuous Distributions 44
2.6 Stochastic Processes 50
2.7 Markov Chains 51
Chapter 3 RELIABILITY ANALYSIS OF SERIES PARALLEL
SYSTEMS 59
3.1 Introduction 59
3.2 Reliability Block Diagrams 60
3.3 Series Systems 62
3.4 Parallel Systems 67
3.5 Series Parallel Systems 70
3.6 K-out-of-M Systems 73
3.7 Open and Short Circuit Failures 75
3.8 Standby Systems 81
vi
Chapter 4 RELIABILITY ANALYSIS NONSERIES PARALLEL
SYSTEMS 87
4.1 Introduction 87
4.2 Path Determination 89
4.3 Boolean Algebra Methods 91
4.4 A Particular Method 93
4.5 Cut Set Approach 96
4.6 Delta-Star Method 97
4.7 Logical Signal Relations Method 100
4.8 Baye's Theorem Method 103
Chapter 5 RELIABILITY PREDICTION 107
5.1 Introduction 107
5.2 Purpose 108
5.3 Classification 109
5.4 Information Sources for Failure Rate Data 109
5.5 General Requirements 111
5.6 Prediction Methodologies 113
5.7 Software Prediction Packages 120
5.8 Role and Limitation of Reliability Prediction 121
Chapter 6 RELIABILITY ALLOCATION 122
6.1 Introduction 122
6.2 Subsystems Reliability Improvement 123
6.3 Apportionment for New Units 128
6.4 Criticality 135
Chapter 7 REDUNDANCY TECHNIQUES FOR RELIABILITY
OPTIMIZATION 140
7.1 Introduction 140
7.2 Signal Redundancy 141
7.3 Time Redundancy 142
7.4 Software Redundancy 142
7.5 Hardware Redundancy 143
vii
Chapter 8 MAINTAINABILITY AND AVAILABILITY 153
8.1 Introduction 153
8.2 Forms of Maintenance 155
8.3 Measures of Maintainability and Availability 157
8.4 Maintainability Function 162
8.5 Availability Function 163
8.6 Two Unit Parallel System with Repair 168
8.7 Preventive Maintenance 171
8.8 Provisioning of Spares 175
Chapter 9 RELIABILITY TESTING 178
9.1 Introduction 178
9.2 Kinds of Testing 179
9.3 Component Reliability Measurements 185
9.4 Parametric Methods 189
9.5 Confidence Limits 196
9.6 Accelerated Testing 201
9.7 Equipment Acceptance Testing 209
9.8 Reliability Growth Testing 211
Chapter 10 SOFTWARE RELIABILITY 216
10.1 Importance 216
10.2 Software Reliability and Hardware Reliability 218
10.3 Failures and Faults 219
10.4 Software Reliability 225
10.5 Software Reliability Models 228
10.6 Execution Time Component 232
10.7 Calendar Time Component 241
Chapter 11 RELIABILITY ANALYSIS OF SPECIAL SYSTEMS 246
11.1 Computer Communication Networks 246
11.2 Phased Mission Systems 250
11.3 Common Cause Failures 256
11.4 Reliability and Capacity Integration 268
viii
Chapter 12 ECONOMICS OF RELIABILITY ENGINEERING 272
12.1 Introduction 272
12.2 Reliability Costs 272
12.3 Effect of Reliability on Cost 274
12.4 Reliability Achievement Cost Models 276
12.5 Reliability Utility Cost Models 280
12.6 Availability Cost Models for Parallel Systems 284
12.7 Cost Effective Choice of Subsystems 285
12.8 Replacement Policies 288
Chapter 13 RELIABILITY MANAGEMENT 293
13.1 Introduction 293
13.2 Management Objectives 295
13.3 Top Management's Role in Reliability and Quality Control
Programs 297
13.4 Cost Effectiveness Considerations 299
13.5 The Management Matrix 301
13.6 Reliability and Quality Control Facilities and Equipment 304
13.7 Reliability Data 306
13.8 Training 311
Chapter 14 RELIABILITYAPPLICATIONS 316
14.1 Instrument Landing System 316
14.2 Banking System 329
PROBLEMS 335
ANSWERS TO ODD NUMBERED PROBLEMS 363
REFERENCES 367
SUBJECT INDEX 378
PREFACE
The growth of present day societies in population, transportation,
communication and technology points towards the use of larger and more
complex systems. It took man 250,000 years to arrive at agricultural
revolution; 25,000 years to arrive at industrial revolution; and only 150
years to attain the space age and we really do not know where will we go
from here. We know for certain, however, that the coming age will involve
the use of still larger and more complex systems.
The importance of reliability has assumed new dimensions in the recent
years primarily because of the complexity of larger systems and the
implications of their failure. Unreliability in the modern age of technology
besides causing the operational inefficiency and uneconomical maintenance
can also endanger human life. The transition towards thinking about
Reliability is obviously difficult because it requires a change of mentality; but
difficult does not mean impossible.
In its most wider sense, the word Reliability has a very important meaning:
Re-Liability which simply means that it is liability, not once but again and
again, from designers, manufacturers, inspectors, vendors to users and on
all those who are involved with a system in any way to make it reliable.
Much attention is being paid, more than ever before, to the quality and
reliability of engineering systems.
It is of course not easy to decide how much reliability is required and how
much one can afford to pay for it. However, Defence, Aeronautical, Space,
and Nuclear Power generation systems are some prime examples where
compromise with quality and reliability just cannot be made; for a
compromise here could mean much not only in terms of money but also the
loss of many precious lives.
ix
x
Author's 20 years of experience as Reliability Educator, Researcher and
Consultant made it abundantly clear that although every Industrial
Organisation desired to equip its Scientists, Engineers and Managers with
the knowledge of Reliability Concepts and Applications, yet this has not been
achieved. A detailed study reveals that the major bottlenecks for this
situation are the non-availability of qualified faculty for their continuing
education programs, the non-availability of reliability related courses at most
Universities or Schools, as well as the lack of availability of a good text. This
made the author to put his knowledge and experience in the form of the
present text book.
This text is intended to be useful for senior undergraduate and graduate
students in engineering schools as also for professional engineers, reliability
administrators and managers. It was difficult for the author to keep away
from the temptation of including many of his research papers published in
the reputed journals but a very concerted effort has been made to keep the
book ideally suitable for a first course or even for a novice in the discipline of
reliability engineering. This text has primarily emerged from the lecture notes
which the author used for delivering courses to the students at his Institution
and also several courses which were organized for the engineers in the
Industrial Organizations. The text has therefore, been class room tested till
the qualification of acceptance testing stage. A number of solved examples
have been added to make the subject clear during studies. Many problems
have also been given at the end so that the reader could voluntarily test
himself/herself. The answers to odd numbered problems have been given as
test verification.
Much of the subject matter for the text has been taken from the lecture
notes of the courses which the author co-ordinated for the benefit of
practising engineers. Some of the contributors to these lecture notes deserve
my special acknowledgment. These are: Professor Krishna Gopal,
Dr.V.K.Sharma, Ms.Shashwati and MS.Namrata of Regional Engineering
College, Kurukshetra; Professor N. Viswanadham, and Professor V. V. S. Sarma
of Indian Institute of Science, Bangalore; Shri A.K.Sinha and Shri P.K.Rao of
Centre for Reliability Engineering, Madras; Shri Siharan De and Shri
Chandragupta from Indian Space Research Organization. In addition to these
lecture notes, I have drawn very heavily from several books and papers
already published in the field of reliability engineering. It is my pleasure to
specially mention my obligation to Balagurusamy, Dhillon, Bazovsky, Ireson,