oSIST prEN IEC 62506:2023

Methods for product accelerated testing

Verfahren für beschleunigte Produktprüfungen

Méthodes d'essais accélérés de produits

Metode za pospešeno preskušanje proizvodov

General Information

• Status: Not Published
• Public Enquiry End Date: 31-Jan-2023
• ICS: 03.120.01 - Quality in general
• ICS: 19.020 - Test conditions and procedures in general
• ICS: 21.020 - Characteristics and design of machines, apparatus, equipment
• Technical Committee: I11 - Imaginarni 11
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 18-Nov-2022
• Due Date: 07-Apr-2023
• Ref Project: prEN IEC 62506:2022 - Methods for product accelerated testing

RELATIONS

• Revised: SIST EN 62506:2014 - Methods for product accelerated testing
• Effective Date: 04-Jun-2020

Standards Content (sample)

SLOVENSKI STANDARD
oSIST prEN IEC 62506:2023
01-januar-2023
Metode za pospešeno preskušanje proizvodov
Methods for product accelerated testing
Verfahren für beschleunigte Produktprüfungen
Méthodes d'essais accélérés de produits
Ta slovenski standard je istoveten z: prEN IEC 62506:2022
ICS:
03.120.01 Kakovost na splošno Quality in general
19.020 Preskuševalni pogoji in Test conditions and
postopki na splošno procedures in general
21.020 Značilnosti in načrtovanje Characteristics and design of
strojev, aparatov, opreme machines, apparatus,
equipment
oSIST prEN IEC 62506:2023 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN IEC 62506:2023
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oSIST prEN IEC 62506:2023
56/1966/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 62506 ED2
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2022-11-11 2023-02-03
SUPERSEDES DOCUMENTS:
56/1889/CD, 56/1897B/CC
IEC TC 56 : DEPENDABILITY
SECRETARIAT: SECRETARY:
United Kingdom Ms Stephanie Lavy
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:
Other TC/SCs are requested to indicate their interest, if
any, in this CDV to the secretary.
FUNCTIONS CONCERNED:
EMC ENVIRONMENT QUALITY ASSURANCE SAFETY

SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING

Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft
for Vote (CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
CENELEC online voting system.

This document is still under study and subject to change. It should not be used for reference purposes.

Recipients of this document are invited to submit, with their comments, notification of any relevant patent rights of

which they are aware and to provide supporting documentation.
TITLE:
Methods for product accelerated testing
PROPOSED STABILITY DATE: 2025
NOTE FROM TC/SC OFFICERS:

Copyright © 2022 International Electrotechnical Commission, IEC. All rights reserved. It is permitted to download this

electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee positions.

You may not copy or "mirror" the file or printed version of the document, or any part of it, for any other purpose without

permission in writing from IEC.
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1 CONTENTS

2 FOREWORD ............................................................................................................................. 5

3 INTRODUCTION ...................................................................................................................... 7

4 1 Scope ................................................................................................................................... 8

5 2 Normative references .......................................................................................................... 8

6 3 Terms, definitions, symbols and abbreviations .................................................................. 9

7 3.1 Terms and definitions ........................................................................................... 9

8 3.2 Symbols and abbreviated terms .......................................................................... 11

9 4 General description of the accelerated test methods ......................................................... 12

10 4.1 Cumulative damage model ................................................................................. 12

11 4.2 Classification, methods and types of test acceleration ....................................... 14

12 4.2.1 General .............................................................................................. 14

13 4.2.2 Type A: qualitative accelerated tests ................................................ 15

14 4.2.3 Type B: quantitative accelerated tests .............................................. 15

15 4.2.4 Type C: quantitative time and event compressed tests ..................... 16

16 5 Accelerated test models .................................................................................................... 17

17 5.1 Type A, qualitative accelerated tests .................................................................. 17

18 5.1.1 Highly accelerated limit tests (HALT) ............................................. 17

19 5.1.2 Highly accelerated stress test (HAST) .............................................. 21

20 5.1.3 Highly accelerated stress screening/audit (HASS/HASA) ............... 21

21 5.1.4 Engineering aspects of HALT and HASS ........................................ 22

22 5.2 Type B and C – Quantitative accelerated test methods ...................................... 23

23 5.2.1 Purpose of quantitative accelerated testing ...................................... 23

24 5.2.2 Physical basis for the quantitative accelerated Type B test

25 methods ............................................................................................. 23

26 5.2.3 Type C tests, time (C ) and event (C ) compression ....................... 24

1 2

27 5.3 Failure mechanisms and test design ................................................................... 26

28 5.4 Determination of stress levels, profiles and combinations in use and test –

29 stress modelling .................................................................................................. 27

30 5.4.1 General .............................................................................................. 27

31 5.4.2 Step-by-step procedure ..................................................................... 27

32 5.5 Multiple stress acceleration methodology – Type B tests .................................. 27

33 5.6 Single and multiple stress acceleration for Type B tests .................................... 30

34 5.6.1 Single stress acceleration methodology ............................................ 30

35 5.6.2 Stress models with stress varying as a function of time – Type

36 B tests ............................................................................................... 37

37 5.6.3 Stress models that depend on repetition of stress applications

38 – Fatigue models ............................................................................... 39

39 5.6.4 Other acceleration models – Time and event compression .............. 40

40 5.7 Acceleration of quantitative reliability tests ....................................................... 41

41 5.7.1 Reliability requirements, goals, and use profile ............................... 41

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42 5.7.2 Reliability demonstration or life tests ............................................... 43

43 5.7.3 Testing of components for a reliability measure .............................. 53

44 5.7.4 Reliability measures for components and systems/items ................. 54

45 5.8 Accelerated reliability compliance or evaluation tests ....................................... 54

46 5.9 Accelerated reliability growth testing................................................................. 56

47 5.10 Guidelines for accelerated testing ....................................................................... 56

48 5.10.1 Accelerated testing for multiple stresses and the known use

49 profile ................................................................................................ 56

50 5.10.2 Level of accelerated stresses ............................................................. 57

51 5.10.3 Accelerated reliability and verification tests .................................... 57

52 6 Accelerated testing strategy in product development ....................................................... 57

53 6.1 Accelerated testing sampling plan ...................................................................... 57

54 6.2 General discussion about test stresses and durations .......................................... 58

55 6.3 Testing components for multiple stresses ........................................................... 59

56 6.4 Accelerated testing of assemblies ....................................................................... 59

57 6.5 Accelerated testing of systems ........................................................................... 59

58 6.6 Analysis of test results ........................................................................................ 59

59 7 Limitations of accelerated testing methodology ............................................................... 60

60 Annex A (informative) Highly accelerated limit test (HALT)................................................ 61

61 Annex B (informative) Accelerated reliability compliance and growth test design ............... 66

62 Annex C (informative) Comparison between HALT and conventional accelerated

63 testing ........................................................................................Error! Bookmark not defined.

64 Annex D (informative) Estimating the activation energy, E ................................................. 74

65 Annex E (informative) Calibrated accelerated life testing (CALT) ........................................ 76

66 Annex F (informative) Example on how to estimate empirical factors .................................. 78

67 Annex G (informative) Determination of acceleration factors by testing to failure ............... 82

68 Bibliography ............................................................................................................................. 87

70 Figure 1 – Probability density functions (PDF) for cumulative damage, degradation,

71 and test types ............................................................................................................................ 13

72 Figure 2 – Relationship of PDFs of the item strength vs. load in use ...................................... 18

73 Figure 3 – How uncertainty of load and strength affects the test policy .................................. 19

74 Figure 4 – PDFs of operating and destruct limits as a function of applied stress .................... 20

75 Figure 5 – Line plot for Arrhenius reaction model .................................................................. 34

76 Figure 6 – Plot for determination of the activation energy ...................................................... 35

77 Figure 7 – Multiplier of the test stress duration for demonstration of required reliability

78 for compliance or reliability growth testing ..............................Error! Bookmark not defined.

79 Figure 8 – Multiplier of the duration of the load application for the desired reliability .. Error!

80 Bookmark not defined.

81 Figure B.1 – Reliability as a function of multiplier k and for combinations of

82 parameters a and b .....................................................................Error! Bookmark not defined.

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83 Figure B.2 – Determination of the multiplier k .........................Error! Bookmark not defined.

84 Figure B.3 – Determination of the growth rate .........................Error! Bookmark not defined.

85 Figure D.1 – Plotting failures to estimate the activation energy E ......................................... 75

86 Figure F.1 – Weibull graphical data analysis ........................................................................... 80

87 Figure F.2 – Scale parameter as a function of the temperature range ..... Error! Bookmark not

88 defined.

89 Figure F.3 – Probability of failure as a function of number of cycles ∆T = 50 °C ........... Error!

90 Bookmark not defined.

91 Figure G.1 – Weibull plot of the three data sets ....................................................................... 83

92 Figure G.2 – Scale parameters’ values fitted with a power lineError! Bookmark not defined.

94 Table 1 – Test types mapped to the development cycle ........................................................... 14

95 Table A.1 – Summary of HALT test results for a DC/DC converter ....................................... 63

96 Table A.2 – Summary of HALT results from a medical system .............................................. 64

97 Table A.3 – Summary of HALT results for a Hi-Fi equipment ............................................... 65

98 Table B.1 – Environmental stress conditions of an automotive electronic device .................. 68

99 Table B.2 – Item use parameters ...............................................Error! Bookmark not defined.

100 Table B.3 – Assumed item use profile ......................................Error! Bookmark not defined.

101 Table B.4 – Worksheet for determination of use times to failures ......... Error! Bookmark not

102 defined.

103 Table B.5 – Data for reliability growth plotting ........................Error! Bookmark not defined.

104 Table C.1 – Comparison between HALT and conventional accelerated testing............... Error!

105 Bookmark not defined.

106 Table F.1 − Probability of failure of test samples A and B ...................................................... 79

107 Table F.2 – Data transformation for Weibull plotting ..............Error! Bookmark not defined.

108 Table G.1 – Voltage test failure data for Weibull distribution ................................................. 82

109
110
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111 INTERNATIONAL ELECTROTECHNICAL COMMISSION
112 ____________
113
114 METHODS FOR PRODUCT ACCELERATED TESTING
115
116 FOREWORD

117 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national

118 electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions

119 concerning standardization in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes

120 International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter

121 referred to as “IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested in

122 the subject dealt with may participate in this preparatory work. International, governmental and non-governmental organizations liaising

123 with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for Standardization (ISO)

124 in accordance with conditions determined by agreement between the two organizations.

125 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international consensus of opinion on

126 the relevant subjects since each technical committee has representation from all interested IEC National Committees.

127 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National Committees in that sense.

128 While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate, IEC cannot be held responsible

129 for the way in which they are used or for any misinterpretation by any end user.

130 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the

131 maximum extent possible in their national and regional publications. Any divergence between any IEC Publication and the

132 corresponding national or regional publication shall be clearly indicated in the latter.

133 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity assessment services and,

134 in some areas, access to IEC marks of conformity. IEC is not responsible for any services carried out by independent certification

135 bodies.

136 6) All users should ensure that they have the latest edition of this publication.

137 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its technical

138 committees and IEC National Committees for any personal injury, property damage or other damage of any nature whatsoever, whether

139 direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this IEC

140 Publication or any other IEC Publications.

141 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable for the

142 correct application of this publication.

143 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

144 be held responsible for identifying any or all such patent rights.

145 International Standard IEC 62506 has been prepared by IEC technical committee 56:

146 Dependability.

147 Edition 2 correct a number of errors in Edition 1, mainly in Clause 5.7.2.3 and Annex B. A

148 number of calculation errors in the examples in Annex B and F have been corrected. Further

149 the references have been updated and the symbols have been revised.
150 Further the references have been updated.
151 The text of this standard is based on the following documents:
FDIS Report on voting
56/1503/FDIS 56/1513/RVD
152

153 Full information on the voting for the approval of this standard can be found in the report on

154 voting indicated in the above table.

155 This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

156
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157 The committee has decided that the contents of this publication will remain unchanged until the

158 stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to

159 the specific publication. At this date, the publication will be
160 • reconfirmed,
161 • withdrawn,
162 • replaced by a revised edition, or
163 • amended.
164

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 document using a colour printer.

165
166
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167 INTRODUCTION

168 Many reliability or failure investigation test methods have been developed and most of them are

169 currently in use. These methods are used to either determine product reliability or to identify

170 potential product failure modes, and have been considered effective as demonstrations of

171 reliability:
172 – fixed duration,
173 – sequential probability ratio,
174 – reliability growth tests,
175 – tests to failure, etc.

176 Such tests, although very useful, are usually lengthy, especially when the product reliability that

177 has to be demonstrated was high. The reduction in time-to-market periods as well as

178 competitive product cost, increase the need for efficient and effective accelerated testing. Here,

179 the tests are shortened through the application of increased stress levels or by increasing the

180 speed of application of repetitive stresses, thus facilitating a quicker assessment and growth of

181 product reliability through failure mode discovery and mitigation.
182 There are two distinctly different approaches to reliability activities:

183 – the first approach verifies, through analysis and testing, that there are no potential failure modes in

184 the product that are likely to be activated during the expected life time of the product under the

185 expected operating conditions and usage profile;

186 – the second approach estimates how many failures can be expected after a given time under the

187 expected operating conditions and usage profile.

188 Accelerated testing is a method appropriate for both cases, but used quite differently. The first

189 approach is associated with qualitative accelerated testing, where the goal is identification of

190 potential faults that eventually might result in product field failures. The second approach is

191 associated with quantitative accelerated testing where the product reliability may be estimated

192 based on the results of accelerated simulation testing that can be related back to the use of the

193 environment and usage profile.

194 Accelerated testing can be applied to multiple levels of items containing hardware or software.

195 Different types of reliability testing, such as fixed duration, sequential test-to-failure, success

196 test, reliability demonstration, or reliability growth/improvement tests can be candidates for

197 accelerated methods. This standard provides guidance on selected, commonly used

198 accelerated test types. This standard should be used in conjunction with statistical test plan

199 standards such as IEC 61123, IEC 61124, IEC 61649 and IEC 61710.

200 The relative merits of various methods and their individual or combined applicability in

201 evaluating a given system or item, should be reviewed by the product design team (including

202 reliability engineering) prior to selection of a specific test method or a combination of methods.

203 For each method, consideration should also be given to the test time, results produced,

204 credibility of the results, data required to perform meaningful analysis, life cycle cost impact,

205 complexity of analysis and other identified factors.

206 In this standard the term item is used as defined in IEC 60050-192 covering physical products

207 as well as software. Services are however not covered by this standard.
208
209
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210 METHODS FOR PRODUCT ACCELERATED TESTING
211
212
213
214 Scope

215 This International Standard provides guidance on the application of various accelerated test

216 techniques for measurement or improvement of item reliability. Identification of potential failure

217 modes that could be experienced in the use of an item and their mitigation is instrumental to

218 ensure dependability of an item.

219 The object of the methods is to either identify potential design weakness or provide information

220 on item reliability, or to achieve necessary reliability/availability improvement, all within a

221 compressed or accelerated period of time. This standard addresses accelerated testing of non-

222 repairable and repairable systems. It can be used for probability ratio sequential tests, fixed

223 duration tests and reliability improvement/growth tests, where the measure of reliability may

224 differ from the standard probability of failure occurrence.

225 This standard also extends to present accelerated testing or production screening methods that

226 would identify weakness introduced into the item by manufacturing error, which could

227 compromise item reliability.
228 Normative references

229 The following documents, in whole or in part, are normatively referenced in this document.

230 For dated references, only the edition cited applies. For undated references, the latest edition

231 of the referenced document (including any amendments) applies.

232 IEC 60050-192:2015/AMD1:2016 Standard | Amendment 1 - International Electrotechnical

233 Vocabulary (IEV) - Part 192: Dependability.
234
235 IEC 60068 (all parts), Environmental testing

236 IEC 60300-3-4, Dependability management – Part 3: Application guide-Section 4: Guide to the

237 specification of dependability requirements

238 IEC 60300-3-5, Dependability management – Part 3-5: Application guide – Reliability test

239 conditions and statistical test principles
240 IEC 60605-2, Equipment reliability testing – Part 2: Design of test cycles

241 IEC 60605-4: 2001 Standard | Equipment reliability testing - Part 4: Statistical procedures for

242 exponential distribution - Point estimates
243

244 IEC 60605-6: 2007 Equipment reliability testing - Part 6: Tests for the validity and estimation

245 of the constant failure rate and constant failure intensity
246 IEC 60721 (all parts), Classification of environmental conditions

247 IEC 60812, Analysis techniques for system reliability – Procedure for failure mode and effects

248 analysis (FMEA)
249 IEC 61014:2003, Programmes for reliability growth
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250 IEC 61123:2019 Reliability testing - Compliance test plans for success ratio

251 IEC 61124:2012, Reliability testing – Compliance tests for constant failure rate and constant

252 failure intensity

253 IEC 61163-1, Reliability stress screening – Part 1:Repairable assemblies manufactured in lots.

254
255 IEC 61163-2, Reliability stress screening – Part 2: Electronic components
256 IEC 61164:2004, Reliability growth – Statistical test and estimation methods
257 IEC 61649:2008, Weibull analysis

258 IEC 61709, Electronic components – Reliability – Reference conditions for failure rates and

259 stress models for conversion
260 IEC 61710, Power law model – Goodness-of-fit tests and estimation methods
261 IEC 62740:2015 Root cause analysis (RCA)

262 IEC/TR 62380, Reliability data handbook – Universal model for reliability prediction of

263 electronics components, PCBs and equipment

264 IEC 62429, Reliability growth – Stress testing for early failures in unique complex systems

265 Terms, definitions, symbols and abbreviations

266 For the purposes of this document, the term and definitions given in IEC 60050-192, as well as

267 the following, apply.

268 NOTE Symbols for reliability, availability and maintainability measures follow those of

269 IEC 60050-192:2015, where available.
270 3.1 Terms and definitions
271 3.1.1
272 activation energy
273 E

274 empirical factor for estimating the acceleration caused by a change in absolute temperature

275 Note 1 to entry: Activation energy is usually measured in electron volts per degree Kelvin.

276 3.1.2
277 detection screen
278 low stress level exposure to detect intermittent faults
279 3.1.3
280 event compression

281 increasing stress repetition frequency to be considerably higher levels than it is in the field

282 3.1.4
283 highly accelerated limit test
284 HALT

285 test or sequence of tests intended to identify the most likely failure modes of the product in a defined stress

286 environment
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287 Note 1 to entry: HALT is sometimes spelled out as the highly accelerated life test (as it was originally named in error).

288 However, as a non-measurable accelerated test, it does not provide information on life duration, but on the magnitude of

289 stress which represents the limit of the design.
290 3.1.5
291 highly accelerated stress audit
292 HASA

293 process monitoring tool where a sample from a production lot is tested to detect potential weaknesses in a

294 product caused by manufacturing
295 3.1.6
296 highly accelerated stress screening
297 HASS

298 screening intended to identify latent defects in a product caused by manufacturing process or control errors

299 3.1.7
300 item
301 subject being considered

302 Note 1 to entry: The item may be an individual part, component, device, functional unit, equipment, subsystem,

303 or system.

304 Note 2 to entry: The item may consist of hardware, software, people or any combination thereof.

305 Note 3 to entry: The item is often comprised of elements that may each be individually considered. See "sub-

306 item", definition 192-01-02 and "indenture level", definition 192-01-05.

307 Note 4 to entry: IEC 60050-191:1990 (now withdrawn; replaced by IEC 60050-192:2015) identified the term

308 “entity” as an English synonym, which is not true for all applications.

309 Note 5 to entry: The definition for item in IEC 60050-191:1990 (now withdrawn; replaced by IEC 60050-

310 192:2015) is a description rather than a definition. This new definition provides meaningful substitution throughout

311 this document. The words of the former definition form new note 1.
312 [SOURCE: IEC 60050-192:—, definition 192-01-01]
313 3.1.9
314 life time,
315 time interval from first use until user requirements are no longer met

316 NOTE 1 to entry: The end of life time is usually called failure of the component.

317

318 NOTE 2 to entry: The end of life is often defined as the time where a specified percentage of the components

319 have failed, for example stated as a B10 or L10 value for 10% accumulated failures.

320 3.1.10
321 precipitation screen

322 screening profile to precipitate, through failure, conversion of latent into revealed faults

323 3.1.11
324 step stress test
325 step stress test

326 test in which the applied stress is increased, after each specified interval, until failure occurs or a predetermined

327 stress level is reached
...