IEC 61508-7-2010 Functional safety of electrical electronic programmable electronic safety-related systems - Part 7 Overview of techniques and measures《电气、电子、程序可控的电子安全相关系统的功能性安全.第7部分 技术和措施概述》.pdf

1、 IEC 61508-7Edition 2.0 2010-04INTERNATIONAL STANDARD NORME INTERNATIONALEFunctional safety of electrical/electronic/programmable electronic safety-related systems Part 7: Overview of techniques and measures Scurit fonctionnelle des systmes lectriques/lectroniques/lectroniques programmables relatifs

2、 la scurit Partie 7: Prsentation de techniques et mesures IEC61508-7:2010 THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2010 IEC, Geneva, Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic

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16、 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 61508-7Edition 2.0 2010-04INTERNATIONAL STANDARD NORME INTERNATIONALEFunctional safety of electrical/electronic/programmable electronic sa

17、fety-related systems Part 7: Overview of techniques and measures Scurit fonctionnelle des systmes lectriques/lectroniques/lectroniques programmables relatifs la scurit Partie 7: Prsentation de techniques et mesures INTERNATIONAL ELECTROTECHNICAL COMMISSION COMMISSION ELECTROTECHNIQUE INTERNATIONALE

18、XGICS 25.040.40; 35.240.50 PRICE CODECODE PRIXISBN 978-2-88910-530-4 Registered trademark of the International Electrotechnical Commission Marque dpose de la Commission Electrotechnique Internationale 2 61508-7 IEC:2010 CONTENTS FOREWORD.3 INTRODUCTION.5 1 Scope.7 2 Normative references .9 3 Definit

19、ions and abbreviations9 Annex A (informative) Overview of techniques and measures for E/E/PE safety-related systems: control of random hardware failures (see IEC 61508-2)10 Annex B (informative) Overview of techniques and measures for E/E/PE safety related systems: avoidance of systematic failures (

20、see IEC 61508-2 and IEC 61508-3) 27 Annex C (informative) Overview of techniques and measures for achieving software safety integrity (see IEC 61508-3).54 Annex D (informative) A probabilistic approach to determining software safety integrity for pre-developed software .107 Annex E (informative) Ove

21、rview of techniques and measures for design of ASICs .112 Annex F (informative) Definitions of properties of software lifecycle phases.126 Annex G (informative) Guidance for the development of safety-related object oriented software132 Bibliography134 Index 137 Figure 1 Overall framework of IEC 6150

22、8.8 Table C.1 Recommendations for specific programming languages .86 Table D.1 Necessary history for confidence to safety integrity levels .107 Table D.2 Probabilities of failure for low demand mode of operation 108 Table D.3 Mean distances of two test points 109 Table D.4 Probabilities of failure f

23、or high demand or continuous mode of operation .110 Table D.5 Probability of testing all program properties .111 Table F.1 Software Safety Requirements Specification 126 Table F.2 Software design and development: software architecture design 127 Table F.3 Software design and development: support too

24、ls and programming language.128 Table F.4 Software design and development: detailed design 128 Table F.5 Software design and development: software module testing and integration.129 Table F.6 Programmable electronics integration (hardware and software)129 Table F.7 Software aspects of system safety

25、validation .130 Table F.8 Software modification.130 Table F.9 Software verification.131 Table F.10 Functional safety assessment 131 Table G.1 Object Oriented Software Architecture.132 Table G.2 Object Oriented Detailed Design133 Table G.3 Some Oriented Detailed terms.133 61508-7 IEC:2010 3 INTERNATI

26、ONAL ELECTROTECHNICAL COMMISSION _ FUNCTIONAL SAFETY OF ELECTRICAL/ELECTRONIC/ PROGRAMMABLE ELECTRONIC SAFETY-RELATED SYSTEMS Part 7: Overview of techniques and measures FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all nat

27、ional 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, Technic

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33、n shall be clearly indicated in the 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

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35、l injury, property damage or other 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 refere

36、nces cited in this publication. Use 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 i

37、dentifying any or all such patent rights. International Standard IEC 61508-7 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 2000. Thi

38、s edition constitutes a technical revision. This edition has been subject to a thorough review and incorporates many comments received at the various revision stages. 4 61508-7 IEC:2010 The text of this standard is based on the following documents: FDIS Report on voting 65A/554/FDIS 65A/578/RVDFull

39、information on the voting for the 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 Functiona

40、l safety of electrical / electronic / 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 dat

41、a related to the specific publication. At this date, the publication will be reconfirmed, withdrawn, replaced by a revised edition, or amended. 61508-7 IEC:2010 5 INTRODUCTION Systems comprised of electrical and/or electronic elements have been used for many years to perform safety functions in most

42、 application sectors. Computer-based 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,

43、 it is essential that those responsible 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 progr

44、ammable electronic (E/E/PE) elements 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 produc

45、t and application sector international 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 21, 22 and 37). In most situations, safety is achieved by a number of

46、systems which rely on many technologies (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

47、 all the safety-related systems making 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.

48、It is recognized that there is a great 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 sp

49、ecific to the application. This International 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, thr