EN 50126-1 EUROPEANSTANDARD NORMEEUROPEENNE EUROPAISCHE NORM October2017 ICS 29.280; 45.020 Supersedes EN 50126-1:1999 English Version Railway Applications - The Specification and Demonstration of Reliability, Availability, Maintainability and Safety (RAMS) - Part 1: Generic RAMS Process Applications ferroviaires - Specification et demonstration de Bahnanwendungen-SpezifikationundNachweisvon ia fiabilite, de la disponibilite, de la maintenabilite et de la Zuverlassigkeit, Verfugbarkeit, Instandhaltbarkeit und sécurite (FDMS) - Partie 1: Processus FMDS genérique Sicherheit (RAMS) - Teil 1: Generischer RAMS Prozess This European Standard was approved by CENELEC on 2017-07-03. 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. Management Centreorto 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 CEN-CENELEC Management Centre 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, iceland, Ireland, Itaiy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands,Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. European Committee for Electrotechnical Standardization Comité Europeen de Normalisation Electrotechnique Europaisches Komitee fir Elektrotechnische Normung CEN-CENELEC Management Centre:Avenue Marnix17,B-100o Brussels @ 2017 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members. Ref. No. EN 50126-1:2017 E EN 50126-1:2017 (E) Contents Page European foreword 6 Introduction Scope ... .8 2 Normative references .9 3 Terms and definitions 9 4 Abbreviations. .20 5 Railway RAMS. 20 5.1 Introduction 20 5.2 Multi-level System approach. 5.2.1 Concepts of system hierarchy . 5.2.2 System requirements and characteristics .. .22 5.2.3 Defining a system .. .23 5.3 Railway system overview.. .23 5.3.1 Introduction... 23 5.3.2 Stakeholders involved in a railway system 23 5.3.3 Railway system structure and apportionment of RAMS requirements .24 5.4 Railway RAMS and quality of service. 24 5.5 Elements of railway RAMS.. 5.6 Factors influencing railway RAMS. 27 5.6.1 General. .27 5.6.2 Classes of failures .27 5.6.3 Derivation of detailed railway specific influencing factors .27 5.6.4 Human factors . .32 5.7 Specification of railway RAMS requirements .34 5.7.1 General. .34 5.7.2 RAMS specification.. 5.8 Risk based approach ... 5.9 Risk reduction strategy . 5.9.1 Introduction.... 5.9.2 Reduction of risks related to safety .35 5.9.3 Reduction of risks related to RAM... ..36 6 Management of railway RAMS - general requirements .37 6.1 Introduction.. .37 6.2 Life cycle for the system under consideration. .37 6.3 Risk assessment... .45 6.4 Organisational requirements. .46 6.4.1 Introduction.. 46 6.4.2 Requirements. 47 6.5 Application of this standard and adaptability to project scope and size 6.5.1 General requirements .... 6.5.2 Case of complex systems with different hierarchical levels.. .49 6.5.3 Renewal within existing systems .. .50 2 EN 50126-1:2017 (E) 6.5.4 Re-use or adaptation of a system with previous acceptance. .50 6.6 General requirements on RAMS documentation 51 6.7 Verification and Validation . 6.7.1 Introduction. 6.7.2 Verification 6.7.3 Validation .52 6.8 Independent Safety Assessment .53 6.8.1 Objectives. .53 6.8.2 Activities .54 7 RAMS life cycle .55 7.1 General ..55 7.2 Phase 1: Concept ... ...55 7.2.1 Objectives. .55 7.2.2 Activities.. .56 7.2.3 Deliverables. .56