EN 61508-7:2010

Functional safety of electrical/electronic/programmable electronic safety-related systems - Part 7: Overview of techniques and measures

IEC 61508-7:2010 contains an overview of various safety techniques and measures relevant to IEC 61508-2 and IEC 61508-3.The references should be considered as basic references to methods and tools or as examples, and may not represent the state of the art. This edition constitutes a technical revision. It has been subject to a thorough review and incorporates many comments received at the various revision stages. NEW! Also available:  IEC Standards+ 61508:2010, containing all parts, together with a commented Redline version. Changes made in this 2nd edition are highlighted and commented by a leading world expert.

Funktionale Sicherheit sicherheitsbezogener elektrischer/elektronischer/programmierbarer elektronischer Systeme - Teil 7: Überblick über Verfahren und Maßnahmen

Sécurité fonctionnelle des systèmes électriques/électroniques/électroniques programmables relatifs à la sécurité - Partie 7: Présentation de techniques et mesures

La CEI 61508-7:2010 contient une présentation de différentes techniques et mesures de sécurité pertinentes pour la CEI 61508-2 et la CEI 61508-3. Il convient que les références citées soient considérées comme des références fondamentales des méthodes et outils, ou comme des exemples; elles peuvent ne pas représenter la technologie de pointe. Cette deuxième édition annule et remplace la première édition publiée en 1998 dont elle constitue une révision technique. Elle a fait l'objet d'une révision approfondie et intègre de nombreux commentaires reçus lors des différentes phases de révision.

Funkcijska varnost električnih/elektronskih/elektronsko programirljivih varnostnih sistemov - 7. del: Pregled tehnik in ukrepov (IEC 61508-7:2010)

1.1 Ta del IEC 61508 vsebuje pregled različnih varnostnih tehnik in ukrepov, pomembnih za IEC 61508-2 in IEC 61508-3.
Reference je treba obravnavati kot osnovne reference za metode in orodja ali kot primere in morda ne predstavljajo zadnjega stanja.
1.2 IEC 61508-1, IEC 61598-2, IEC 61508-3 in IEC 61508-4 so osnovne varnostne objave, čeprav ta status ne velja v okviru nezapletenih varnostnih sistemov E/E/PE (glej točko 3.4.3 IEC 61508-4). Kot osnovne varnostne objave so namenjeni temu, da jih uporabljajo tehnični odbori pri pripravi standardov v skladu z načeli, opredeljenimi v Vodilu IEC 104 in Vodilu ISO/IEC 51. IEC 61508-1, IEC 61508-2, IEC 61508-3 in IEC 61508-4 se lahko tudi uporabijo kot samostojne objave. Horizontalno varnostno delovanje tega mednarodnega standarda ne velja za medicinsko opremo v skladu s serijo IEC 60601.
1.3 Ena od odgovornosti tehničnega odbora je, če je primerno, da uporabi temeljne varnostne objave pri pripravi svojih objav. V tem okviru zahteve, preskusne metode ali preskusni pogoji te temeljne varnostne objave ne veljajo, razen če se objave, ki so jih pripravili tehnični odbori, nanje izrecno sklicujejo ali jih vključujejo.
1.4 Slika 1 prikazuje celoten okvir za dele od 1 do 7serije IEC 61508 in nakazuje vlogo IEC 61508-7 pri doseganju funkcijske varnosti varnostnih sistemov E/E/PE.

General Information

• Status: Published
• Publication Date: 27-May-2010
• Withdrawal Date: 30-Apr-2013
• ICS: 25.040.40 - Industrial process measurement and control
• ICS: 35.240.50 - IT applications in industry
• Technical Committee: CLC/TC 65X - Industrial-process measurement, control and automation
• Drafting Committee: IEC/SC 65A - IEC_SC_65A
• Parallel Committee: IEC/SC 65A - IEC_SC_65A
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 28-May-2010
• Completion Date: 28-May-2010
• Ref Project: SIST EN 61508-7:2011 - Functional safety of electrical/electronic/programmable electronic safety-related systems - Part 7: Overview of techniques and measures (IEC 61508-7:2010)

Relations

• Replaces: EN 61508-7:2001 - Functional safety of electrical/electronic/programmable electronic safety-related systems - Part 7: Overview of techniques and measures
• Effective Date: 28-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
01-maj-2011
1DGRPHãþD
SIST EN 61508-7:2007
)XQNFLMVNDYDUQRVWHOHNWULþQLKHOHNWURQVNLKHOHNWURQVNRSURJUDPLUOMLYLKYDUQRVWQLK
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Functional safety of electrical/electronic/programmable electronic safety-related systems
- Part 7: Overview of techniques and measures (IEC 61508-7:2010)
Funktionale Sicherheit sicherheitsbezogener
elektrischer/elektronischer/programmierbarer elektronischer Systeme - Teil 7: Überblick
über Verfahren und Maßnahmen (IEC 61508-7:2010)
Sécurité fonctionnelle des systèmes électriques/électroniques/électroniques
programmables relatifs à la sécurité - Partie 7: Présentation de techniques et mesures
(CEI 61508-7:2010)
Ta slovenski standard je istoveten z: EN 61508-7:2010
ICS:
25.040.40 Merjenje in krmiljenje Industrial process
industrijskih postopkov measurement and control
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 61508-7
NORME EUROPÉENNE
May 2010
EUROPÄISCHE NORM
ICS 25.040.40; 35.240.50 Supersedes EN 61508-7:2001

English version
Functional safety of electrical/electronic/programmable electronic safety-
related systems -
Part 7: Overview of techniques and measures
(IEC 61508-7:2010)
Sécurité fonctionnelle des systèmes Funktionale Sicherheit sicherheitsbezogener
électriques/électroniques/électroniques elektrischer/elektronischer/programmierbarer
programmables relatifs à la sécurité - elektronischer Systeme -
Partie 7: Présentation de techniques Teil 7: Überblick über Verfahren
et mesures und Maßnahmen
(CEI 61508-7:2010) (IEC 61508-7:2010)

This European Standard was approved by CENELEC on 2010-05-01. 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 61508-7:2010 E
Foreword
The text of document 65A/554/FDIS, future edition 2 of IEC 61508-7, prepared by SC 65A, System
aspects, of IEC TC 65, Industrial-process measurement, control and automation, was submitted to the
IEC-CENELEC parallel vote and was approved by CENELEC as EN 61508-7 on 2010-05-01.
This European Standard supersedes EN 61508-7:2001.
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
national standard or by endorsement (dop) 2011-02-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2013-05-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 61508-7:2010 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:
[1] IEC 60068-1:1988 NOTE  Harmonized as EN 60068-1:1994 (not modified).
[2] IEC 60529:1989 NOTE  Harmonized as EN 60529:1991 (not modified).
[3] IEC 60812:2006 NOTE  Harmonized as EN 60812:2006 (not modified).
[4] IEC 60880:2006 NOTE  Harmonized as EN 60880:2009 (not modified).
[5] IEC 61000-4-1:2006 NOTE  Harmonized as EN 61000-4-1:2007 (not modified).
[6] IEC 61000-4-5:2005 NOTE  Harmonized as EN 61000-4-5:2006 (not modified).
[8] IEC 61025:2006 NOTE  Harmonized as EN 61025:2007 (not modified).
[9] IEC 61069-5:1994 NOTE  Harmonized as EN 61069-5:1995 (not modified).
[10] IEC 61078:2006 NOTE  Harmonized as EN 61078:2006 (not modified).
[11] IEC 61131-3:2003 NOTE  Harmonized as EN 61131-3:2003 (not modified).
[12] IEC 61160:2005 NOTE  Harmonized as EN 61160:2005 (not modified).
[13] IEC 61163-1:2006 NOTE  Harmonized as EN 61163-1:2006 (not modified).
[14] IEC 61164:2004 NOTE  Harmonized as EN 61164:2004 (not modified).
[15] IEC 61165:2006 NOTE  Harmonized as EN 61165:2006 (not modified).
[16] IEC 61326-3-1:2008 NOTE  Harmonized as EN 61326-3-1:2008 (not modified).
[17] IEC 61326-3-2:2008 NOTE  Harmonized as EN 61326-3-2:2008 (not modified).
[18] IEC 81346-1:2009 NOTE  Harmonized as EN 81346-1:2009 (not modified).

- 3 - EN 61508-7:2010
[21] IEC 61511 series NOTE  Harmonized in EN 61511 series (not modified).
[22] IEC 62061:2005 NOTE  Harmonized as EN 62061:2005 (not modified).
[23] IEC 62308:2006 NOTE  Harmonized as EN 62308:2006 (not modified).
[37] IEC 61800-5-2 NOTE  Harmonized as EN 61800-5-2.
[38] IEC 60601 series NOTE  Harmonized in EN 60601 series (partially modified).
[39] IEC 60068-2-1 NOTE  Harmonized as EN 60068-2-1.
[40] IEC 60068-2-2 NOTE  Harmonized as EN 60068-2-2.
[41] ISO 9000 NOTE  Harmonized as EN ISO 9000.
[42] IEC 61508-1:2010 NOTE  Harmonized as EN 61508-1:2010 (not modified).
[43] IEC 61508-2:2010 NOTE  Harmonized as EN 61508-2:2010 (not modified).
[44] IEC 61508-3:2010 NOTE  Harmonized as EN 61508-3:2010 (not modified).
[45] IEC 61508-6:2010 NOTE  Harmonized as EN 61508-6:2010 (not modified).
__________
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 61508-4 2010 Functional safety of EN 61508-4 2010
electrical/electronic/programmable electronic
safety-related systems -
Part 4: Definitions and abbreviations

IEC 61508-7 ®
Edition 2.0 2010-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Functional safety of electrical/electronic/programmable electronic safety-related
systems –
Part 7: Overview of techniques and measures

Sécurité fonctionnelle des systèmes électriques/électroniques/électroniques
programmables relatifs à la sécurité –
Partie 7: Présentation de techniques et mesures

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
XG
CODE PRIX
ICS 25.040.40; 35.240.50 ISBN 978-2-88910-530-4
– 2 – 61508-7 © IEC:2010
CONTENTS
FOREWORD.3
INTRODUCTION.5
1 Scope.7
2 Normative references .9
3 Definitions and abbreviations.9
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 (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) Overview 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
software.132
Bibliography.134
Index .137

Figure 1 – Overall framework of IEC 61508.8

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 for 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 tools 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 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 Design.133
Table G.3 – Some Oriented Detailed terms .133

61508-7 © IEC:2010 – 3 –
INTERNATIONAL 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 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 Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements 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 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,
...