IEC_61508-1.pdf

61508-1 IEC:19971 Version 4.0 05/12/97COMMISSIONCEIELECTROTECHNIQUEIECINTERNATIONALE61508-1INTERNATIONALELECTROTECHNICALCOMMISSIONFunctional safety of electrical/electronic/programmable electronic safety-related systemsPart 1:General requirements61508-1 IEC:19972 Version 4.0 05/12/97ContentsForeword.5Introduction.61Scope.82Normative references.113Definitions and abbreviations.124Conformance to this standard.135Documentation.145.1Objectives.145.2Requirements.146Management of functional safety.166.1Objectives.166.2Requirements.167Overall safety lifecycle requirements.187.1General.187.2Concept.307.3Overall scope definition.307.4Hazard and risk analysis.317.5Overall safety requirements.337.6Safety requirements allocation.357.7Overall operation and maintenance planning.407.8Overall safety validation planning.417.9Overall installation and commissioning planning.427.10 Realisation:E/E/PES.437.11 Realisation:other technology.447.12 Realisation:external risk reduction facilities.447.13 Overall installation and commissioning.447.14 Overall safety validation.457.15 Overall operation,maintenance and repair.467.16 Overall modification and retrofit.487.17 Decommissioning or disposal.507.18Verification.518Functional safety assessment.538.1Objective.5361508-1 IEC:19973 Version 4.0 05/12/978.2Requirements.53Annex A(informative)Example documentation structure.56A.1General.56A.2Safety lifecycle document structure.57A.3Physical document structure.60A.4List of documents.62Annex B(informative)Competence of persons.63B.1Objective.63B.2General considerations.63Annex C(informative)Bibliography.63Figures1Overall framework of this standard.112Overall safety lifecycle.193E/E/PES safety lifecycle(in realisation phase).224Software safety lifecycle(in realisation phase).255Relationship of overall safety lifecycle to E/E/PES and software safety lifecycles.256Allocation of safety requirements to the E/E/PE safety-related systems,other technologysafety-related systems and external risk reduction facilities.387Example operations and maintenance activities model.478Example operation and maintenance management model.489Example modification procedure model.50A.1 Structuring information into document sets for user groups.61A.2 Structuring information for large complex systems and small low complexity systems.62Tables1Overall safety lifecycle:overview.262Safety integrity levels:target failure measures for a safety function,allocated to an E/E/PEsafety-related system operating in low demand mode of operation.383Safety integrity levels:target failure measures for a safety function,allocated to an E/E/PEsafety-related system operating in high demand or continuous mode of operation.384Minimum levels of independence of those carrying out functional safety assessment(overallsafety lifecycle phases 1 to 8 and 12 to 16 inclusive(see figure 2).5561508-1 IEC:19974 Version 4.0 05/12/975Minimum levels of independence of those carrying out functional safety assessment(overallsafety lifecycle phase 9-includes all phases of E/E/PES and software safety lifecycles(seefigures 2,3 and 4).55A.1 Example documentation structure for information related to the overall safety lifecycle.58A.2 Example documentation structure for information related to the E/E/PES safety lifecycle.59A.3 Example documentation structure for information related to the software safety lifecycle.6061508-1 IEC:19975 Version 4.0 05/12/97FUNCTIONAL SAFETY OF ELECTRICAL/ELECTRONIC/PROGRAMMABLEELECTRONIC SAFETY-RELATED SYSTEMSPart 1:General requirementsFOREWORD1)The IEC(International Electrotechnical Commission)is a worldwide organization for standardization comprising all nationalelectrotechnical committees(IEC national committees).The object of the IEC is to promote international cooperation on allquestions concerning standardization in the electrical and electronic fields.To this end and in addition to other activities,theIEC publishes international standards.Their preparation is entrusted to technical committees;any IEC national committeeinterested in the subject dealt with may participate in this preparatory work.International,governmental and non-governmentalorganizations liaising with the IEC also participate in this preparation.The IEC collaborates closely with the InternationalOrganization for Standardization(ISO)in accordance with conditions determined by agreement between the twoorganizations.2)The formal decisions or agreements of the IEC on technical matters,prepared by technical committees on which all thenational committees having a special interest therein are represented,express,as nearly as possible,an internationalconsensus of opinion on the subjects dealt with.3)They have the form of recommendations for international use published in the form of standards,technical reports or guidesand they are accepted by the national committees in that sense.4)In order to promote international unification,IEC national committees undertake to apply IEC international standardstransparently to the