IEC 61508-5-2010 Functional safety of electrical electronic programmable electronic safety-related systems - Part 5 Examples of methods for the determination of.pdf

1、 IEC 61508-5 Edition 2.0 2010-04 INTERNATIONAL STANDARD NORME INTERNATIONALE Functional safety of electrical/electronic/programmable electronic safety-related systems Part 5: Examples of methods for the determination of safety integrity levels Scurit fonctionnelle des systmes lectriques/lectroniques

2、/lectroniques programmables relatifs la scurit Partie 5: Exemples de mthodes pour la dtermination des niveaux dintgrit de scurit IEC 61508-5:2010 THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2010 IEC, Geneva, Switzerland All rights reserved. Unless otherwise specified, no part of this publicati

3、on may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either IEC or IECs member National Committee in the country of the requester. If you have any questions about IEC copyright or have an enqu

4、iry about obtaining additional rights to this publication, please contact the address below or your local IEC member National Committee for further information. Droits de reproduction rservs. Sauf indication contraire, aucune partie de cette publication ne peut tre reproduite ni utilise sous quelque

5、 forme que ce soit et par aucun procd, lectronique ou mcanique, y compris la photocopie et les microfilms, sans laccord crit de la CEI ou du Comit national de la CEI du pays du demandeur. Si vous avez des questions sur le copyright de la CEI ou si vous dsirez obtenir des droits supplmentaires sur ce

6、tte publication, utilisez les coordonnes ci-aprs ou contactez le Comit national de la CEI de votre pays de rsidence. IEC Central Office 3, rue de Varemb CH-1211 Geneva 20 Switzerland Email: inmailiec.ch Web: www.iec.ch About the IEC The International Electrotechnical Commission (IEC) is the leading

7、global organization that prepares and publishes International Standards for all electrical, electronic and related technologies. About IEC publications The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the latest edition, a corrigenda

8、or an amendment might have been published. Catalogue of IEC publications: www.iec.ch/searchpub The IEC on-line Catalogue enables you to search by a variety of criteria (reference number, text, technical committee,). It also gives information on projects, withdrawn and replaced publications. IEC Just

9、 Published: www.iec.ch/online_news/justpub Stay up to date on all new IEC publications. Just Published details twice a month all new publications released. Available on-line and also by email. Electropedia: www.electropedia.org The worlds leading online dictionary of electronic and electrical terms

10、containing more than 20 000 terms and definitions in English and French, with equivalent terms in additional languages. Also known as the International Electrotechnical Vocabulary online. Customer Service Centre: www.iec.ch/webstore/custserv If you wish to give us your feedback on this publication o

11、r need further assistance, please visit the Customer Service Centre FAQ or contact us: Email: csciec.ch Tel.: +41 22 919 02 11 Fax: +41 22 919 03 00 A propos de la CEI La Commission Electrotechnique Internationale (CEI) est la premire organisation mondiale qui labore et publie des normes internation

12、ales pour tout ce qui a trait llectricit, llectronique et aux technologies apparentes. A propos des publications CEI Le contenu technique des publications de la CEI est constamment revu. Veuillez vous assurer que vous possdez ldition la plus rcente, un corrigendum ou amendement peut avoir t publi. C

13、atalogue des publications de la CEI: www.iec.ch/searchpub/cur_fut-f.htm Le Catalogue en-ligne de la CEI vous permet deffectuer des recherches en utilisant diffrents critres (numro de rfrence, texte, comit dtudes,). Il donne aussi des informations sur les projets et les publications retires ou rempla

14、ces. Just Published CEI: www.iec.ch/online_news/justpub Restez inform sur les nouvelles publications de la CEI. Just Published dtaille deux fois par mois les nouvelles publications parues. Disponible en-ligne et aussi par email. Electropedia: www.electropedia.org Le premier dictionnaire en ligne au

15、monde de termes lectroniques et lectriques. Il contient plus de 20 000 termes et dfinitions en anglais et en franais, ainsi que les termes quivalents dans les langues additionnelles. Egalement appel Vocabulaire Electrotechnique International en ligne. Service Clients: www.iec.ch/webstore/custserv/cu

16、stserv_entry-f.htm Si vous dsirez nous donner des commentaires sur cette publication ou si vous avez des questions, visitez le FAQ du Service clients ou contactez-nous: Email: csciec.ch Tl.: +41 22 919 02 11 Fax: +41 22 919 03 00 IEC 61508-5 Edition 2.0 2010-04 INTERNATIONAL STANDARD NORME INTERNATI

17、ONALE Functional safety of electrical/electronic/programmable electronic safety-related systems Part 5: Examples of methods for the determination of safety integrity levels Scurit fonctionnelle des systmes lectriques/lectroniques/lectroniques programmables relatifs la scurit Partie 5: Exemples de mt

18、hodes pour la dtermination des niveaux dintgrit de scurit INTERNATIONAL ELECTROTECHNICAL COMMISSION COMMISSION ELECTROTECHNIQUE INTERNATIONALE X ICS 25.040.40 PRICE CODE CODE PRIX ISBN 978-2-88910-528-1 Registered trademark of the International Electrotechnical Commission Marque dpose de la Commissi

19、on Electrotechnique Internationale 2 61508-5 IEC:2010 CONTENTS FOREWORD.3 INTRODUCTION.5 1 Scope.7 2 Normative references .9 3 Definitions and abbreviations9 Annex A (informative) Risk and safety integrity General concepts.10 Annex B (informative) Selection of methods for determining safety integrit

20、y level requirements.21 Annex C (informative) ALARP and tolerable risk concepts .24 Annex D (informative) Determination of safety integrity levels A quantitative method 27 Annex E (informative) Determination of safety integrity levels Risk graph methods .30 Annex F (informative) Semi-quantitative me

21、thod using layer of protection analysis (LOPA) .38 Annex G (informative) Determination of safety integrity levels A qualitative method hazardous event severity matrix44 Bibliography46 Figure 1 Overall framework of the IEC 61508 series 8 Figure A.1 Risk reduction general concepts (low demand mode of

22、operation) .14 Figure A.2 Risk and safety integrity concept 14 Figure A.3 Risk diagram for high demand applications.15 Figure A.4 Risk diagram for continuous mode operation 16 Figure A.5 Illustration of common cause failures (CCFs) of elements in the EUC control system and elements in the E/E/PE saf

23、ety-related system.17 Figure A.6 Common cause between two E/E/PE safety-related systems 18 Figure A.7 Allocation of safety requirements to the E/E/PE safety-related systems, and other risk reduction measures 20 Figure C.1 Tolerable risk and ALARP.25 Figure D.1 Safety integrity allocation example for

24、 safety-related protection system.29 Figure E.1 Risk Graph: general scheme.33 Figure E.2 Risk graph example (illustrates general principles only).34 Figure G.1 Hazardous event severity matrix example (illustrates general principles only) .45 Table C.1 Example of risk classification of accidents .26

25、Table C.2 Interpretation of risk classes 26 Table E.1 Example of data relating to risk graph (Figure E.2).35 Table E.2 Example of calibration of the general purpose risk graph .36 Table F.1 LOPA report.40 61508-5 IEC:2010 3 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ FUNCTIONAL SAFETY OF ELECTRICAL/

26、ELECTRONIC/ PROGRAMMABLE ELECTRONIC SAFETY-RELATED SYSTEMS Part 5: Examples of methods for the determination of safety integrity levels FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees

27、(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 Repor

28、ts, 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 no

29、n- governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal decisions or agreements

30、of IEC on technical matters express, as nearly as possible, an international consensus of opinion on the relevant subjects since each technical committee has representation from all interested IEC National Committees. 3) IEC Publications have the form of recommendations for international use and are

31、 accepted by IEC National Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation by any end user. 4) In order to promote inter

32、national uniformity, IEC National Committees undertake to apply IEC Publications transparently to the maximum extent possible in their national and regional publications. Any divergence between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in t

33、he latter. 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any services carried out by independent certification bodies. 6) All user

34、s should ensure 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 othe

35、r damage of any 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. U

36、se of the referenced 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

37、 rights. International Standard IEC 61508-5 has been prepared by subcommittee 65A: System aspects, of IEC technical committee 65: Industrial-process measurement, control and automation. This second edition cancels and replaces the first edition published in 1998. This edition constitutes a technical

38、 revision. This edition has been subject to a thorough review and incorporates many comments received at the various revision stages. 4 61508-5 IEC:2010 The text of this standard is based on the following documents: FDIS Report on voting 65A/552/FDIS 65A/576/RVD Full information on the voting for th

39、e approval of this standard can be found in the report on voting indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2 A list of all parts of the IEC 61508 series, published under the general title Functional safety of electrical / electron

40、ic / programmable electronic safety-related systems, can be found on the IEC website. The committee has decided that the contents of this publication will remain unchanged until the stability date indicated on the IEC web site under “http:/webstore.iec.ch“ in the data related to the specific publica

41、tion. At this date, the publication will be reconfirmed, withdrawn, replaced by a revised edition, or amended. 61508-5 IEC:2010 5 INTRODUCTION Systems comprised of electrical and/or electronic elements have been used for many years to perform safety functions in most application sectors. Computer-ba

42、sed systems (generically referred to as programmable electronic systems) are being used in all application sectors to perform non-safety functions and, increasingly, to perform safety functions. If computer system technology is to be effectively and safely exploited, it is essential that those respo

43、nsible for making decisions have sufficient guidance on the safety aspects on which to make these decisions. This International Standard sets out a generic approach for all safety lifecycle activities for systems comprised of electrical and/or electronic and/or programmable electronic (E/E/PE) eleme

44、nts that are used to perform safety functions. This unified approach has been adopted in order that a rational and consistent technical policy be developed for all electrically-based safety-related systems. A major objective is to facilitate the development of product and application sector internat

45、ional standards based on the IEC 61508 series. NOTE 1 Examples of product and application sector international standards based on the IEC 61508 series are given in the Bibliography (see references 1, 2 and 3). In most situations, safety is achieved by a number of systems which rely on many technolog

46、ies (for example mechanical, hydraulic, pneumatic, electrical, electronic, programmable electronic). Any safety strategy must therefore consider not only all the elements within an individual system (for example sensors, controlling devices and actuators) but also all the safety-related systems maki

47、ng up the total combination of safety-related systems. Therefore, while this International Standard is concerned with E/E/PE safety-related systems, it may also provide a framework within which safety-related systems based on other technologies may be considered. It is recognized that there is a gre

48、at variety of applications using E/E/PE safety-related systems in a variety of application sectors and covering a wide range of complexity, hazard and risk potentials. In any particular application, the required safety measures will be dependent on many factors specific to the application. This Inte

49、rnational Standard, by being generic, will enable such measures to be formulated in future product and application sector international standards and in revisions of those that already exist. This International Standard considers all relevant overall, E/E/PE system and software safety lifecycle phases (for example, from initial concept, though design