1、PUBLISHED DOCUMENTPD CLC/TR 50126-2:2007Railway applications The specification and demonstration of Reliability, Availability, Maintainability and Safety (RAMS) Part 2: Guide to the application of EN 50126-1 for safetyICS 45.020g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g
2、53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58PD CLC/TR 50126-2:2007This Published Document was published under the authority of the Standards Policy and Strategy Committee on 30 April 2007 BSI 2007ISBN 978 0 580 50488
3、 4National forewordThis Published Document was published by BSI. It is the UK implementation of CLC/TR 50126-2:2007. The UK participation in its preparation was entrusted to Technical Committee GEL/9, Railway electrotechnical applications.A list of organizations represented on GEL/9 can be obtained
4、on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Amendments issued since publicationAmd. No. Date CommentsTECHNICAL REPORTCLC/TR 50126-2RAPPORT TECHNIQUETECHNISCHER BERICHTFebruary 2
5、007CENELECEuropean Committee for Electrotechnical StandardizationComit Europen de Normalisation ElectrotechniqueEuropisches Komitee fr Elektrotechnische NormungCentral Secretariat: rue de Stassart 35, B - 1050 Brussels 2007 CENELEC - All rights of exploitation in any form and by any means reserved w
6、orldwide for CENELEC members.Ref. No. CLC/TR 50126-2:2007 EICS 45.020English versionRailway applications -The specification and demonstration of Reliability, Availability,Maintainability and Safety (RAMS) -Part 2: Guide to the application of EN 50126-1 for safetyApplications ferroviaires -Spcificati
7、on et dmonstrationde la fiabilit, de la disponibilit,de la maintenabilitet de la scurit (FDMS) -Partie 2:Guide pour lapplicationde lEN 50126-1 la scuritBahnanwendungen -Spezifikation und Nachweisder Zuverlssigkeit, Verfgbarkeit,Instandhaltbarkeit, Sicherheit (RAMS) -Teil 2: Leitfaden zur Anwendungde
8、r EN 50126-1 fr SicherheitThis Technical Report was approved by CENELEC on 2007-01-22.CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, theCzech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,Li
9、thuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,Sweden, Switzerland and the United Kingdom.ForewordThe European Standard EN 50126-1:1999, which was prepared jointly by the Technical CommitteesCENELEC TC 9X, Electric and electronic application
10、s for railways, and CEN TC 256, Railway applications,under mode 4 co-operation, deals with the specification and demonstration of Reliability, Availability,Maintainability and Safety (RAMS) for railway applications.A guide to the application of EN 50126-1 for safety of railway systems (this CLC/TR 5
11、0126-2) and a guide forthe application to EN 50126-1 for rolling stock RAM (CLC/TR 50126-3:2006) have been produced to forminformative parts of EN 50126-1:1999. Whilst this CLC/TR 50126-2 is applicable to all railway systems,including rolling stock, CLC/TR 50126-3:2006 is applicable to rolling stock
12、 RAM only.This Technical Report, which was prepared by WG 8 of the Technical Committee CENELEC TC 9X, formsan informative part of EN 50126-1:1999 and contains guidelines for the application of EN 50126-1 for thesafety of railway systems.The text of the draft was submitted to the vote and was approve
13、d by CENELEC as CLC/TR 50126-2 on2007-01-22.-CLC/TR 50126-2:2007ContentsIntroduction.8 1 Scope.9 2 References.11 3 Definitions and abbreviations.12 3.1 Guidance on the interpretation of terms and definitions used in EN 50126-1 .12 3.2 Additional safety terms.15 3.3 Abbreviations.17 4 Guidance on bod
14、ies/entities involved and concepts of system hierarchy and safety.17 4.1 Introduction.17 4.2 Bodies/entities involved in a system.18 4.3 Concepts of system hierarchy.18 4.3.1 Rail transport system environment and system hierarchy .19 4.4 Safety concepts.19 4.4.1 Hazard perspective .19 4.4.2 Risk.21
15、4.4.3 Risk normalising .22 5 Generic risk model for a typical railway system and check list of common functional hazards .23 5.1 Introduction.23 5.2 Generic risk model .23 5.3 Risk assessment process.24 5.3.1 Introduction.24 5.3.2 Generic process .24 5.4 Application of the risk assessment process .2
16、8 5.4.1 Depth of analysis.29 5.4.2 Preliminary hazard analysis .29 5.4.3 Qualitative and Quantitative assessment.30 5.4.4 Use of historical data.31 5.4.5 Sensitivity analysis .32 5.4.6 Risk assessment during life cycle phases.32 5.5 Check-list of common functional hazards and hazard identification .
17、33 5.5.1 Introduction.33 5.5.2 Hazard grouping structures.34 5.5.3 Check-list of Hazards.35 6 Guidance on application of functional safety, functional safety requirements and SI targets,risk apportionment and application of SILs.36 6.1 Introduction.36 6.2 Functional and technical safety.36 6.2.1 Sys
18、tem characteristics .36 6.2.2 Railway system structure and safety requirements .37 6.2.3 Safety related functional and technical characteristics and overall system safety .37 CLC/TR 50126-2:20076.3 General considerations for risk apportionment .38 6.3.1 Introduction.38 6.3.2 Approaches to apportionm
19、ent of safety targets .38 6.3.3 Use of THRs.40 6.4 Guidance on the concept of SI and the application of SILs .40 6.4.1 Safety integrity.40 6.4.2 Using SI concept in the specification of safety requirements.42 6.4.3 Link between THR and SIL .46 6.4.4 Controlling random failures and systematic faults
20、to achieve SI.46 6.4.5 Use and misuse of SILs .49 6.5 Guidance on fail-safe systems .51 6.5.1 Fail-safe concept .51 6.5.2 Designing fail-safe systems.52 7 Guidance on methods for combining probabilistic and deterministic means for safetydemonstration .54 7.1 Safety demonstration .54 7.1.1 Introducti
21、on.54 7.1.2 Detailed guidance on safety demonstration approaches.54 7.1.3 Safety qualification tests.65 7.2 Deterministic methods.65 7.3 Probabilistic methods .65 7.4 Combining deterministic and probabilistic methods.65 7.5 Methods for mechanical and mixed (mechatronic) systems .66 8 Guidance on the
22、 risk acceptance principles.67 8.1 Guidance on the application of the risk acceptance principles .67 8.1.1 Application of risk acceptance principles .67 8.1.2 The ALARP principle.68 8.1.3 The GAMAB (GAME) principle.69 8.1.4 Minimum Endogenous Mortality (MEM) safety principle (EN 50126-1, Clause D.3)
23、 .70 9 Guidance on the essentials for documented evidence or proof of safety (Safety case) .71 9.1 Introduction.71 9.2 Safety case purpose.72 9.3 Safety case scope .72 9.4 Safety case levels .72 9.5 Safety case phases .74 9.6 Safety case structure.75 9.7 Safety assessment .78 9.7.1 The scope of the safety assessor .78 9.7.2 The independence of a safety assessor .78 9.7.3 Competence of the safety assessor.79 9.8 Interfacing with existing systems.79 9.8.1 Systems developed according to the EN 50126-1 process .79 9.8.2 System proven in use.79 9.8.3 Unproven systems.
