1、BSI Standards PublicationRoot cause analysis (RCA)BS EN 62740:2015National forewordThis British Standard is the UK implementation of EN 62740:2015. It is identical to IEC 62740:2015.The UK participation in its preparation was entrusted to TechnicalCommittee DS/1, Dependability.A list of organization
2、s represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions ofa contract. Users are responsible for its correct application. The British Standards Institution 2015.Published by BSI Standards Limited 2015ISBN 978
3、 0 580 79741 5ICS 03.120.01Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 April 2015.Amendments/corrigenda issued since publicationDate Text affectedBRITISH ST
4、ANDARDBS EN 62740:2015EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 62740 April 2015 ICS 03.120.01 English Version Root cause analysis (RCA)(IEC 62740:2015) Analyse de cause initiale (RCA) (IEC 62740:2015) Ursachenanalyse (IEC 62740:2015) This European Standard was approved by CENELEC on 2015-03
5、-20. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obta
6、ined on application to the CEN-CENELEC Management Centre or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified t
7、o the CEN-CENELEC Management Centre has the same status as the official versions.CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
8、 Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,Turkey and the United Kingdom. European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotec
9、hniqueEuropisches Komitee fr Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2015 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members. Ref. No. EN 62740:2015 E EN 62740:2015 - 2 - Foreword The text of docum
10、ent 56/1590/FDIS, future edition 1 of IEC 62740, prepared by IEC/TC 56 “Dependability“ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 62740:2015. The following dates are fixed: latest date by which the document has to be implemented at national level by publication of a
11、n identical national standard or by endorsement (dop) 2015-12-20 latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2018-03-20 Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CENEL
12、EC and/or CEN shall not be held responsible for identifying any or all such patent rights. Endorsement notice The text of the International Standard IEC 62740:2015 was approved by CENELEC as a European Standard without any modification. In the official version, for Bibliography, the following notes
13、have to be added for the standards indicated: IEC 60300-1 NOTE Harmonized as EN 60300-1. IEC 61025 NOTE Harmonized as EN 61025. IEC 61649 NOTE Harmonized as EN 61649. IEC 61163-1 NOTE Harmonized as EN 61163-1. IEC 62508:2010 NOTE Harmonized as EN 62508:2010 (not modified). ISO/IEC 31010:2009 NOTE Ha
14、rmonized as EN 31010:2010 (not modified). BS EN 62740:2015- 3 - EN 62740:2015 Annex ZA (normative) Normative references to international publications with their corresponding European publications The following documents, in whole or in part, are normatively referenced in this document and are indis
15、pensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod), the re
16、levant EN/HD applies. NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here: www.cenelec.eu. Publication Year Title EN/HD Year IEC 60050 Series - International Electrotechnical Vocabulary (IEV) - - BS EN 62740:2015 2 IEC 62740:2015 IEC
17、2015 CONTENTS INTRODUCTION . 8 1 Scope 9 2 Normative references 9 3 Terms, definitions and abbreviations . 9 3.1 Terms and definitions 9 3.2 Abbreviations 12 4 RCA Overview 12 5 The RCA process 13 5.1 Overview. 13 5.2 Initiation 14 5.3 Establishing facts 15 5.4 Analysis 17 5.4.1 Description 17 5.4.2
18、 The analysis team . 18 5.5 Validation 19 5.6 Presentation of results 19 6 Selection of techniques for analysing causes . 20 6.1 General . 20 6.2 Selection of analysis techniques . 20 6.3 Useful tools to assist RCA. 21 Annex A (informative) Summary and criteria of commonly used RCA techniques . 22 A
19、.1 General . 22 A.2 RCA techniques 22 A.3 Criteria 23 Annex B (informative) RCA models 26 B.1 General . 26 B.2 Barrier analysis . 26 B.2.1 Overview . 26 B.2.2 Strengths and limitations . 27 B.3 Reasons model (Swiss cheese model) . 27 B.3.1 Overview . 27 B.3.2 Strengths and limitations . 28 B.4 Syste
20、ms models 28 B.5 Systems theoretic accident model and processes (STAMP) 29 B.5.1 Overview . 29 B.5.2 Strengths and limitations . 29 Annex C (informative) Detailed description of RCA techniques 30 C.1 General . 30 C.2 Events and causal factors (ECF) charting . 30 C.2.1 Overview . 30 C.2.2 Process . 3
21、1 C.2.3 Strengths and limitations . 31 C.3 Multilinear events sequencing (MES) and sequentially timed events plotting (STEP) 32 BS EN 62740:2015IEC 62740:2015 IEC 2015 3 C.3.1 Overview . 32 C.3.2 Process . 32 C.3.3 Strengths and limitations . 33 C.4 The why method 35 C.4.1 Overview . 35 C.4.2 Proces
22、s . 36 C.4.3 Strengths and limitations . 36 C.5 Causes tree method (CTM) . 36 C.5.1 Overview . 36 C.5.2 Process . 39 C.5.3 Strengths and limitations . 39 C.6 Why-because analysis (WBA) . 39 C.6.1 Overview . 39 C.6.2 Process . 42 C.6.3 Strengths and limitations . 42 C.7 Fault tree and success tree me
23、thod 42 C.7.1 Overview . 42 C.7.2 Process . 43 C.7.3 Strengths and limitations . 44 C.8 Fishbone or Ishikawa diagram . 44 C.8.1 Overview . 44 C.8.2 Process . 45 C.8.3 Strengths and limitations . 46 C.9 Safety through organizational learning (SOL) 46 C.9.1 Overview . 46 C.9.2 Process . 46 C.9.3 Stren
24、gths and limitations . 47 C.10 Management oversight and risk tree (MORT) 48 C.10.1 Overview . 48 C.10.2 Process . 48 C.10.3 Strengths and limitations . 48 C.11 AcciMaps 49 C.11.1 Overview . 49 C.11.2 Process . 49 C.11.3 Strengths and limitations . 51 C.12 Tripod Beta . 51 C.12.1 Overview . 51 C.12.2
25、 Process . 52 C.12.3 Strengths and limitations . 52 C.13 Causal analysis using STAMP (CAST) 53 C.13.1 Overview . 53 C.13.2 Process . 56 C.13.3 Strengths and limitations . 57 Annex D (informative) Useful tools to assist root cause analysis (RCA) . 58 D.1 General . 58 D.2 Data mining and clustering te
26、chniques 58 D.2.1 Overview . 58 D.2.2 Example 1 . 58 D.2.3 Example 2 . 58 BS EN 62740:2015 4 IEC 62740:2015 IEC 2015 D.2.4 Example 3 . 59 Annex E (informative) Analysis of human performance 60 E.1 General . 60 E.2 Analysis of human failure 60 E.3 Technique for retrospective and predictive analysis o
27、f cognitive errors (TRACEr) 61 E.3.1 Overview . 61 E.3.2 Process . 62 E.4 Human factors analysis and classification scheme (HFACS) . 63 E.4.1 Overview . 63 E.4.2 Process . 63 Bibliography 66 Figure 1 RCA process 14 Figure B.1 Broken, ineffective and missing barriers causing the focus event 26 Figure
28、 C.1 Example of an ECF chart 31 Figure C.2 Data in an event building block . 32 Figure C.3 Example of a time-actor matrix . 34 Figure C.4 Example of a why tree 35 Figure C.5 Symbols and links used in CTM 37 Figure C.6 Example of a cause tree . 38 Figure C.7 Example of a WBG . 41 Figure C.8 Example o
29、f a fault tree during the analysis . 43 Figure C.9 Example of a Fishbone diagram 45 Figure C.10 Example of a MORT diagram 48 Figure C.11 Example of an AcciMap 50 Figure C.12 Example of a Tripod Beta tree diagram . 52 Figure C.13 Control structure for the water supply in a small town in Canada 55 Fig
30、ure C.14 Example CAST causal analysis for the local Department of health 56 Figure C.15 Example CAST causal analysis for the local public utility operations management . 56 Figure E.1 Example of an TRACEr model 25 61 Figure E.2 Generation of internal error modes . 62 Figure E.3 Level 1: Unsafe acts
31、. 64 Figure E.4 Level 2: Preconditions 64 Figure E.5 Level 3: Supervision Issues 65 Figure E.6 Level 4: Organizational Issues 65 Table 1 Steps to RCA 13 Table A.1 Brief description of RCA techniques . 22 Table A.2 Summary of RCA technique criteria 23 Table A.3 Attributes of the generic RCA technique
32、s . 25 Table B.1 Examples of barriers 27 Table B.2 Example of the barrier analysis worksheet . 27 Table C.1 Direct and indirect causal factors . 47 BS EN 62740:2015IEC 62740:2015 IEC 2015 5 Table E.1 External error modes 63 Table E.2 Psychological error mechanisms 63 BS EN 62740:2015 8 IEC 62740:201
33、5 IEC 2015 INTRODUCTION Root cause analysis (RCA) refers to any systematic process that identifies factors that contributed to a particular event of interest (focus event). RCA is performed with the understanding that events are addressed by understanding the root causes, rather than the immediately
34、 obvious symptoms. RCA aims to reveal root causes so that either the likelihood of them occurring, or their impact if they do occur, can be changed. An important distinction to make is that RCA is used to analyse a focus event that has occurred and therefore analyses the past (a posteriori). However
35、, knowledge of the root causes of past events can lead to actions that generate improvements in the future. This International Standard is intended to reflect current good practices in the conduct of RCA. This standard is general in nature, so that it may give guidance across many industries and sit
36、uations. There may be industry specific standards in existence that establish preferred methodologies for particular applications. If these standards are in harmony with this publication, the industry standards will generally be sufficient. This standard is a generic standard and does not explicitly
37、 address safety or accident investigation although the methods described in this standard may be used for this purpose. BS EN 62740:2015IEC 62740:2015 IEC 2015 9 ROOT CAUSE ANALYSIS (RCA) 1 Scope This International Standard describes the basic principles of root cause analysis (RCA) and specifies th
38、e steps that a process for RCA should include. This standard identifies a number of attributes for RCA techniques which assist with the selection of an appropriate technique. It describes each RCA technique and its relative strengths and weaknesses. RCA is used to analyse the root causes of focus ev
39、ents with both positive and negative outcomes, but it is most commonly used for the analysis of failures and incidents. Causes for such events can be varied in nature, including design processes and techniques, organizational characteristics, human aspects and external events. RCA can be used for in
40、vestigating the causes of non-conformances in quality (and other) management systems as well as for failure analysis, for example in maintenance or equipment testing. RCA is used to analyse focus events that have occurred, therefore this standard only covers a posteriori analyses. It is recognized t
41、hat some of the RCA techniques with adaptation can be used proactively in the design and development of items and for causal analysis during risk assessment; however, this standard focuses on the analysis of events which have occurred. The intent of this standard is to describe a process for perform
42、ing RCA and to explain the techniques for identifying root causes. These techniques are not designed to assign responsibility or liability, which is outside the scope of this standard. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document an
43、d are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60050 (all parts), International Electrotechnical Vocabulary 3 Terms, definitions and abbreviat
44、ions For the purposes of this document, the definitions given in IEC 60050-192, as well as the following, apply. 3.1 Terms and definitions 3.1.1 cause circumstance or set of circumstances that leads to failure or success Note 1 to entry: A cause may originate during specification, design, manufactur
45、e, installation, operation or maintenance. SOURCE: IEC 60050-192:2014, 192-03-11 modified addition of the words “circumstance or” and “or success“ in the term BS EN 62740:2015 10 IEC 62740:2015 IEC 2015 3.1.2 causal factor condition, action, event or state that was necessary or contributed to the oc
46、currence of the focus event 3.1.3 contributory factor condition, action, event or state regarded as secondary, according to the occurrence of the focus event 3.1.4 event occurrence or change of a particular set of circumstances Note 1 to entry: An event can be one or more occurrences, and can have s
47、everal causes. Note 2 to entry: An event can consist of something not happening. Note 3 to entry: An event can sometimes be referred to as an “incident” or “accident”. SOURCE: ISO Guide 73:2009, 3.5.1.3, modified Deletion of Note 4 113.1.5 failure loss of ability to perform as required Note 1 to ent
48、ry: A failure of an item is an event that results in a fault of that item. Note 2 to entry: Qualifiers, such as catastrophic, critical, major, minor, marginal and insignificant, may be used to categorize failures according to the severity of consequences, the choice and definitions of severity crite
49、ria depending upon the field of application. Note 3 to entry: Qualifiers, such as misuse, mishandling and weakness, may be used to categorize failures according to the cause of failure. Note 4 to entry: This is failure of an item, not more generally of behaviour. SOURCE: IEC 60050-192:2014, 192-03-01, modified Introduction of new Note 4 3.1.6 failure mechanism process that leads to failure Note 1 to entry: The process may be physical, chemical,
