EN 62502:2010

SLOVENSKI STANDARD
01-januar-2011
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Analysis techniques for dependability - Event tree analysis (ETA) (IEC 62502:2010)
Verfahren zur Analyse der Zuverlässigkeit - Ereignisbaumanalyse (ETA) (IEC
62502:2010)
Techniques d'analyse de la sûreté de fonctionnement - Analyse par arbre d'événement
(AAE) (CEI 62502:2010)
Ta slovenski standard je istoveten z: EN 62502:2010
ICS:
21.020 =QDþLOQRVWLLQQDþUWRYDQMH Characteristics and design of
VWURMHYDSDUDWRYRSUHPH machines, apparatus,
equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 62502
NORME EUROPÉENNE
November 2010
EUROPÄISCHE NORM
ICS 21.020
English version
Analysis techniques for dependability -
Event tree analysis (ETA)
(IEC 62502:2010)
Techniques d'analyse de la sûreté de Verfahren zur Analyse
fonctionnement - der Zuverlässigkeit -
Analyse par arbre d'événement (AAE) Ereignisbaumanalyse (ETA)
(CEI 62502:2010) (IEC 62502:2010)

This European Standard was approved by CENELEC on 2010-11-01. 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 obtained on
application to the Central Secretariat 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
to the Central Secretariat 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Management Centre: Avenue Marnix 17, B - 1000 Brussels

© 2010 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 62502:2010 E
Foreword
The text of document 56/1380/FDIS, future edition 1 of IEC 62502, prepared by IEC TC 56,
Dependability, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as
EN 62502 on 2010-11-01.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent
rights.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
(dop) 2011-08-01
national standard or by endorsement
– latest date by which the national standards conflicting
(dow) 2013-11-01
with the EN have to be withdrawn
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 62502:2010 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
[12] ISO/IEC 31010 NOTE  Harmonized as EN 31010.
[13] IEC 60300-3-1:2003 NOTE  Harmonized as EN 60300-3-1:2004 (not modified).
[15] IEC 60812:2006 NOTE  Harmonized as EN 60812:2006 (not modified)
[16] IEC 61078:2006 NOTE  Harmonized as EN 61078:2006 (not modified)
[17] IEC 61165:2006 NOTE  Harmonized as EN 61165:2006 (not modified)
[18] IEC 61508 series NOTE  Harmonized in EN 61508 series (not modified)
[19] IEC 61511-3:2003 NOTE  Harmonized as EN 61511-3:2004 (not modified)
[20] IEC 61703:2001 NOTE  Harmonized as EN 61703:2002 (not modified)
[22] IEC 62429:2007 NOTE  Harmonized as EN 62429:2008 (not modified)
[23] IEC 62508:2010 NOTE  Harmonized as EN 62508:2010 (not modified)
1) 2)
[24] IEC 62551 NOTE  Harmonized as EN 62551 (not modified)
__________
1)
To be published.
2)
At draft stage.
- 3 - EN 62502:2010
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Publication Year Title EN/HD Year

IEC 60050-191 1990 International Electrotechnical Vocabulary - -
(IEV) -
Chapter 191: Dependability and quality of
service
IEC 61025 2006 Fault Tree Analysis (FTA) EN 61025 2007

IEC 62502 ®
Edition 1.0 2010-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Analysis techniques for dependability – Event tree analysis (ETA)

Techniques d’analyse de la sûreté de fonctionnement – Analyse par arbre
d’événement (AAE)
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
X
CODE PRIX
ICS 21.020 ISBN 978-2-88912-212-7
– 2 – 62502 © IEC:2010
CONTENTS
FOREWORD.4
INTRODUCTION.6
1 Scope.7
2 Normative references .7
3 Terms, definitions, abbreviations and symbols.7
3.1 Terms and definitions .7
3.2 Abbreviations and symbols.8
3.2.1 Abbreviations .8
3.2.2 Symbols .9
4 General description .9
5 Benefits and limitations of ETA.11
5.1 Benefits.11
5.2 Limitations.11
6 Relationship with other analysis techniques.12
6.1 Combination of ETA and FTA .12
6.2 Layer of protection analysis (LOPA) .13
6.3 Combination with other techniques .13
7 Development of event trees .14
7.1 General .14
7.2 Steps in ETA .14
7.2.1 Procedure.14
7.2.2 Step 1: Definition of the system or activity of interest.15
7.2.3 Step 2: Identification of the initiating events of interest .15
7.2.4 Step 3: Identification of mitigating factors and physical phenomena.16
7.2.5 Step 4: Definition of sequences and outcomes, and their
quantification.16
7.2.6 Step 5: Analysis of the outcomes.17
7.2.7 Step 6: Uses of ETA results.17
8 Evaluation .18
8.1 Preliminary remarks .18
8.2 Qualitative analysis – Managing dependencies.18
8.2.1 General .18
8.2.2 Functional dependencies .19
8.2.3 Structural or physical dependencies .20
8.3 Quantitative analysis .22
8.3.1 Independent sequence of events .22
8.3.2 Fault tree linking and boolean reduction .23
9 Documentation .24
Annex A (informative) Graphical representation .26
Annex B (informative) Examples .27
Bibliography.41

Figure 1 – Process for development of event trees .
Figure 2 – Simple graphical representation of an event tree.18
Figure 3 – Functional dependencies in event trees .20

62502 © IEC:2010 – 3 –
Figure 4 – Modelling of structural or physical dependencies.21
Figure 5 – Sequence of events .22
Figure 6 – Fault tree linking .23
Figure A.1 – Frequently used graphical representation for event trees .26
Figure B.1 – Event tree for a typical fire incident in a diesel generator building.28
Figure B.2 – Simplified event tree for a fire event .29
Figure B.3 – Level-crossing system (LX).31
Figure B.4 – ETA for the level-crossing system.33
Figure B.5 – Simple example .36
Figure B.6 – Fault Tree for the Failure of System 1.36
Figure B.7 – Fault Tree for the Failure of System 2.37
Figure B.8 – Modified event tree .38
Figure B.9 – Event tree with "grouped faults" .39

Table A.1 – Graphical elements .26
Table B.1 – Symbols used in Annex B .29
Table B.2 – System overview.31
Table B.3 – Risk reduction parameters for accidents from Figure B.4 .34

– 4 – 62502 © IEC:2010
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ANALYSIS TECHNIQUES FOR DEPENDABILITY –
EVENT TREE ANALYSIS (ETA)
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardizatio
...