1、 EIA STANDARD Reliability Growth - Statistical Test and Estimation Methods EIA 61164 (IEC 61164:2004 Ed.2.0, IDT) May 2017 EIA 61164 ANSI/EIA 61164-2017 Approved: May 11, 2017 NOTICE EIA Engineering Standards and Publications are designed to serve the public interest through eliminating misunderstan
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5、r Publication. This EIA Standard is identical (IDT) with the International Standard IEC Publication 61164:2004: Reliability Growth - Statistical Test and Estimation Methods. This document is the EIA Standard EIA 61164 Edition 2.0: Reliability Growth - Statistical Test and Estimation Methods. The tex
6、t, figures and tables of IEC 61164:2004 are used in this Standard with the consent of the IEC and the American National Standards Institute (ANSI). The IEC copyrighted material has been reproduced with permission from ANSI. The IEC Foreword and Introduction are not part of the requirements of this s
7、tandard but are included for information purposes only. This Standard does not purport to address all safety problems associated with its use or all applicable regulatory requirements. It is the responsibility of the user of this Standard to establish appropriate safety and health practices and to d
8、etermine the applicability of regulatory limitations before its use. (From Standards Proposal No. 5372.04, formulated under the cognizance of the EIA Dependability Standards Committee). Published by Electronic Components Industry Association 2017 Standards any IEC National Committee interested in th
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14、re that they have the latest edition of this publication. 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its technical committees and IEC National Committees for any personal injury, property damage or other damage of a
15、ny nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications. 8) Attention is drawn to the Normative references cited in this publication. Use of the ref
16、erenced publications is indispensable for the correct application of this publication. 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights. IEC shall not be held responsible for identifying any or all such patent rights. Inte
17、rnational Standard IEC 61164 has been prepared by IEC technical committee 56: Dependability. This second edition cancels and replaces the first edition, published in 1995, and constitutes a technical revision. The main changes with respect to the previous edition are listed below: addition of two st
18、atistical models for reliability growth planning and tracking in the product design phase; statistical methods for the reliability growth programme in the design phase of IEC 61014; addition of the discrete reliability growth model for the test phase; addition of the fixed number of faults model for
19、 the test phase; clarification of the symbols used for various models; addition of real life examples for most of the statistical models; numerical correction of tables in the reliability growth test example. EIA 61164 Page 2 This standard should be used in conjunction with IEC 61014. This bilingual
20、 version (2012-03) corresponds to the monolingual English version, published in 2004-03. The text of this standard is based on the following documents: FDIS Report on voting 56/920/FDIS 56/939/RVD Full information on the voting for the approval of this standard can be found in the report on voting i
21、ndicated in the above table. The French version of this standard has not been voted upon. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. The committee has decided that the contents of this publication will remain unchanged until 2011. At this date, the publicati
22、on will be reconfirmed; withdrawn; replaced by a revised edition, or amended. IMPORTANT The colour inside logo on the cover page of this publication indicates that it contains colours which are considered to be useful for the correct understanding of its contents. Users should therefore print this d
23、ocument using a colour printer. EIA 61164 Page 3 INTRODUCTION This International Standard describes the power law reliability growth model and related projection model and gives step-by-step directions for their use. There are several reliability growth models available, the power law model being on
24、e of the most widely used. This standard provides procedures to estimate some or all of the quantities listed in Clauses 4, 6 and 7 of IEC 61014. Two types of input are required. The first one is for reliability growth planning through analysis and design improvements in the design phase in terms of
25、 the design phase duration, initial reliability, reliability goal, and planned design improvements, along with their expected magnitude. The second input, for reliability growth in the project validation phase, is for a data set of accumulated test times at which relevant failures occurred, or were
26、observed, for a single system, and the time of termination of the test, if different from the time of the final failure. It is assumed that the collection of data as input for the model begins after the completion of any preliminary tests, such as environmental stress screening, intended to stabiliz
27、e the products initial failure intensity. Model parameters estimated from previous test results may be used to plan and predict the course of future reliability growth programmes, provided the conditions are similar. Some of the procedures may require computer programs, but these are not unduly comp
28、lex. This standard presents algorithms for which computer programs should be easy to construct. EIA 61164 Page 4 RELIABILITY GROWTH STATISTICAL TEST AND ESTIMATION METHODS 1 Scope This International Standard gives models and numerical methods for reliability growth assess-ments based on failure data
29、, which were generated in a reliability improvement programme. These procedures deal with growth, estimation, confidence intervals for product reliability and goodness-of-fit tests. 2 Normative references The following referenced documents are indispensable for the application of this document. For
30、dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60050-191:1990, International Electrotechnical Vocabulary (IEV) Chapter 191: Dependability and quality of service IEC 60300-3-5:2001, Depend
31、ability management Part 3-5: Application guide Reliability test conditions and statistical test principles IEC 60605-4, Equipment reliability testing Part 4: Statistical procedures for exponential distribution Point estimates, confidence intervals, prediction intervals and tolerance intervals IEC 60
32、605-6, Equipment reliability testing Part 6: Tests for the validity of the constant failure rate or constant failure intensity assumptions IEC 61014:2003, Programmes for reliability growth 3 Terms and definitions For the purposes of this document, the terms and definitions of IEC 60050-191 and IEC 6
33、1014, together with the following terms and definitions, apply. 3.1 reliability goal desired level of reliability that the product should have at the end of the reliability growth programme 3.2 initial reliability reliability that is estimated for the product in earlier design stages before any pote
34、ntial failure modes or their causes have been mitigated by the design improvement 3.3 reliability growth model for the design phase mathematical model that takes into consideration potential design improvements, and their magnitude to express mathematically reliability growth from start to finish du
35、ring the design period EIA 61164 Page 5 3.4 average product failure rate average product failure rate calculated from its reliability as estimated for a predetermined time period NOTE The change in this failure rate as a function of time is a result of the modifications of the product design. 3.5 de
36、layed modification corrective modification, which is incorporated into the product at the end of a test NOTE A delayed modification is not incorporated during the test. 3.6 improvement effectiveness factor fraction by which the intensity of a systematic failure is reduced by means of corrective modi
37、fication 3.7 type I test time-terminated test reliability growth test which is terminated at a predetermined time, or test with data available through a time which does not correspond to a failure 3.8 type II test failure-terminated test reliability growth test which is terminated upon the accumulat
38、ion of a specified number of failures, or test with data available through a time which corresponds to a failure 4 Symbols For the purposes of this standard, the following symbols apply. a) For 6.1, Clauses A.1 and B.3: T product lifetime such as mission, warranty period or operational time TR0initi
39、al product reliability 0a initial average failure rate of product in design period td number of design modifications at any time during the design period D reliability growth rate resultant from fault mitigation D total number of implemented design improvements Dt total duration of the design period
40、 available for the design improvements t time variable during the design period from 0 to Dt ta average failure rate of product as a function of time during the design period DaGt goal average failure rate at the end of the design period Dt EIA 61164 Page 6 TRGreliability goal of the product to be a
41、ttained during design period TtR , reliability of product as a function of time and design improvements b) For 6.2, Clauses A.2 and B.4: TRGreliability goal of the product to be attained during design period Dt total duration of the design period D reliability growth rate during design period NS rat
42、e of non-systematic (or residual) failures D total number of predicted or implemented design improvements within design period to address weaknesses K total number of distinct classes of fault ikj , general purpose indicators kjp probability of j-th design weakness in fault class k resulting in fail
43、ure during the specified life of the product k expected number of design weaknesses in fault class k resulting in failure during the specified life of the product kD total number of predicted or implemented design improvements within design period to address faults in fault class k k failure rate of
44、 design weaknesses categorized in fault class k TRIinitial reliability at time T TR reliability of product as a function of T Gt expected time to reach reliability goal c) For 7.1.1, 7.1.2, Clauses 9, A.4, B.1, and B.2: D total number of design modifications carried out during product design period
45、to mitigate identified faults tDtotal duration of the design period available for potential design modifications t time variable (during design period 0 t tD) d(t) number of design modifications at any given time t during design period from 0 to tDDreliability growth rate during the design period a0
46、 initial average failure rate of a product in design EIA 61164 Page 7 a(t) product average failure rate variable as a function of time during the design period (0 to tD) R0(T) initial product reliability calculated for a time T (mission or other predetermined time) RG(T) product reliability goal to
47、be attained through design improvement, calculated for a predetermined time R(t) product reliability increase as a function of time and design improvements aG goal average failure rate T predetermined time during a product life (mission, warranty, life) scale parameter for the power law model shape
48、parameter for the power law model CV critical value for hypothesis test d number of intervals for grouped data analysis jiEEE , , mean and individual improvement effectiveness factors I number of distinct types of category B failures observed i, j general purpose indices KAnumber of category A failu
49、res KBnumber of category B failures iK number of i-th type category B failures observed: 1iBiKK M parameter of the Cramr-von Mises test (statistical) N number of relevant failures iN number of relevant failures in i-th interval N(T) accumulated number of failures up to test time T EN(T) expected accumulated number of failures up to test time T t(i1); t(i) endpoints of i-th interval of test time for grouped data analysis T current accumulated relevant test time iT accumulated relevant test time at the i-th
