EN 50126

Rail­way Appli­ca­ti­ons - The Spe­ci­fi­ca­ti­on and Demons­tra­ti­on of Relia­bi­li­ty, Avai­la­bi­li­ty, Main­taina­bi­li­ty and Safety

As experienced engineering partner, we are professionals in defining requirements, performing RAMS management and for the demonstration of reliability and safety in railway applications.

EN 50126 repres­ents, with the par­al­lel appli­ca­ble stan­dards EN 50128/EN 50657 and EN 50129, the area-specific adapt­a­ti­on of the basic safe­ty stan­dard EN 61508 for the rail­way indus­try. The stan­dard EN 50126, which is man­da­to­ry accor­ding to the IRIS (Inter­na­tio­nal Rail­way Indus­try Stan­dard) regu­la­ti­ons, appli­es to all areas of rail­way tech­no­lo­gy. It is requi­red for train pro­tec­tion and signal­ing (signal­ing tech­no­lo­gy), to rol­ling stock and to fixed installations.

The stan­dard deals with the defi­ni­ti­on and veri­fi­ca­ti­on of RAMS for all rail­way appli­ca­ti­ons and at all levels in all rele­vant life cycle phases.

EN 50126 is pri­ma­ri­ly inten­ded for use by rail­way com­pa­nies and rail­way sup­pli­ers. Howe­ver, it has a gene­ric con­tent that it can also be used for other areas out­side of rail­way appli­ca­ti­ons with regard to a sys­te­ma­tic RAMS/LCC spe­ci­fi­ca­ti­on and verification.

Nachweis EN 50126 RAMS Sicherheit Validierung generischer Sicherheitsnachweis spezifischer Sicherheitsnachweis Validierungsbericht EN 50128 EN 50129

Since the update in 2017, EN 50126 has con­sis­ted of two parts:

  • Part 1: Gene­ric RAMS Process 
  • Part 2: Sys­tems Approach to Safety

Part 1 defi­nes the terms behind the acro­nym RAMS and covers the gene­ric aspects of the RAMS life­cy­cle. For this pur­po­se, the RAMS-related tasks are defi­ned in the indi­vi­du­al life cycle pha­ses and a sys­te­ma­tic pro­cess for deter­mi­ning RAMS requi­re­ments is described.

Part 2 covers the safety-related gene­ric aspects of the RAMS life­cy­cle and asso­cia­ted pro­ce­du­res and tools, and pro­vi­des an under­stan­ding of the sys­tems approach to safe­ty. Ins­truc­tions and pro­ce­du­res are presented.

Both parts do not con­tain RAMS tar­get values in detail, requi­re­ments or solu­ti­ons for spe­ci­fic appli­ca­ti­ons. It also does not include any rules or pro­ces­ses for cer­ti­fi­ca­ti­on or the appr­oval process.

RAMS life cycle according to EN 50126 

rams en 50126 standard life cycle method phases

Important standards in relation to EN 50126

General basis standards

ISO/TS 22163, EN 61508, EN 60300

Important standards, which complement EN 50126

EN 50128, EN 50129, EN 50562, EN 50657, EN 50159

We help you with the planning, analysis, verification and validation of the necessary RAMS tasks in all life cycle phases. 

For you as a sup­pli­er, we take over the pre­pa­ra­ti­on of RAMS plans, the imple­men­ta­ti­on of risk ana­ly­ses, the pro­du­cing of RAMS fore­casts, the RAM and safe­ty veri­fi­ca­ti­on inclu­ding the docu­men­ta­ti­on of the ful­fill­ment of the RAMS veri­fi­ca­ti­on tasks as well as the validation.

We sup­port you as the ope­ra­tor with the sys­tem spe­ci­fi­ca­ti­on and with the pre­pa­ra­ti­on of the RAMS requi­re­ments, with the iden­ti­fi­ca­ti­on of hazards and the risk deter­mi­na­ti­on in con­nec­tion with the fail­ure and impact ana­ly­sis and with the quan­ti­fi­ca­ti­on of the risk that is still tolerable. 

In the ope­ra­ti­on and main­ten­an­ce phase, we offer you sui­ta­ble solu­ti­ons for the con­ti­nuous recor­ding of the RAMS-related per­for­mance of the systems.

As an exter­nal part­ner, we gua­ran­tee the inde­pen­dence of the roles requi­red by EN 50126-2.

Depending on your role in the project, we offer you the following services: 

Concept phase – risk assessment (RAMS phases 1-5)
  • iden­ti­fy­ing the RAMS effects of the sys­tem concept 
  • iden­ti­fy­ing RAMS requi­re­ments for simi­lar systems
  • iden­ti­fy­ing the RAMS-related stra­tegy and RAMS-related goals
  • estab­li­shing of the RAMS plan and the vali­da­ti­on plan
  • faci­li­ta­ti­on of the RAMS risk analysis
  • estab­li­shing the RAMS requi­re­ments specification
  • estab­li­shing and updating the hazard log accor­ding to CSM-RA and the RAMS manage­ment report
Implementation and demonstration of compliance with the RAMS requirements (RAMS phases 5-10)
  • updating RAMS and vali­da­ti­on plan
  • updating RAMS analysis
  • per­forming RAM and safe­ty demonstration
  • updating the RAMS manage­ment report
  • estab­li­shing the RAMS vali­da­ti­on report 
  • defi­ni­ti­on and coor­di­na­ti­on of the appli­ca­ti­on con­di­ti­ons for the sys­tem (SRAC)
  • updating the hazard log
Operation, maintenance and decommissioning (RAMS phases 11-12)
  • imple­men­ta­ti­on and main­ten­an­ce of a FRACAS process
  • con­ti­nuous report­ing on RAM per­for­mance and evaluation
  • eva­lua­ti­on of the RAMS-related impacts of decom­mis­sio­ning and disposal
  • updating the operator’s hazard log

Questions and answers about the implementation of EN 50126

Which RAMS documents need to be created and updated during the life cycle?

The basis for RAMS manage­ment over the enti­re life cycle is the com­bi­ned RAMS plan. The veri­fi­ca­ti­on in rela­ti­on to the RAMS requi­re­ments is usual­ly divi­ded into three docu­ments due to the dif­fe­rent objec­ti­ves and con­tent: the RAM veri­fi­ca­ti­on report and the safe­ty case as well as the vali­da­ti­on report.

Depen­ding on the scope and com­ple­xi­ty of the pro­ject, the first two veri­fi­ca­ti­ons can also include the results of the RAMS manage­ment pro­cess for each life cycle phase.

Kee­ping a sepa­ra­te RAMS manage­ment report has pro­ven to be a via­ble solu­ti­on to avoid dupli­ca­ti­on and discrepancy.

set of RAMS documents ram proof verification safety case railway application rams planning engineering partner service

What is the RAM verification report for? 

The RAM veri­fi­ca­ti­on report docu­ments the fea­si­bi­li­ty of the requi­red RAM pro­per­ties of the sys­tem under con­side­ra­ti­on. The rele­vant sys­tem requi­re­ments for envi­ron­men­tal con­di­ti­ons, sup­p­ly sys­tems, sto­cking of spare parts and main­ten­an­ce are con­side­red accordingly.

The methods FMEA, FMECA, FTA are pri­ma­ri­ly used as tools for RAM veri­fi­ca­ti­on. The results show in an ana­ly­ti­cal way under which con­di­ti­ons the deter­mi­ned RAM para­me­ters are met.

The RAM cal­cu­la­ti­ons are based on input values ​​which, if pos­si­ble, are spe­ci­fied and con­firm­ed by the manu­fac­tu­r­ers of the com­pon­ents used.

If no manu­fac­tu­rer infor­ma­ti­on is available, sui­ta­ble refe­rence values ​​from com­pa­ra­ti­ve pro­jects or expert esti­ma­tes are used as an appro­xi­ma­te solu­ti­on. All input values ​​are che­cked by the respon­si­ble experts with regard to plau­si­bi­li­ty, trans­fera­bi­li­ty and appli­ca­bi­li­ty to the sys­tem under consideration.

What content does the safety case for railway applications include?

The safe­ty case asses­ses whe­ther the sys­tem under con­side­ra­ti­on is sui­ta­ble for mee­ting the quan­ti­ta­ti­ve and qua­li­ta­ti­ve safe­ty tar­gets from the safe­ty requi­re­ments based on cur­rent aspects in accordance with the inten­ded appli­ca­ti­on con­di­ti­ons. The veri­fi­ca­ti­on focu­ses on the sys­te­ma­tic reco­gni­ti­on and clas­si­fi­ca­ti­on of all hazards that can be fore­seen under nor­mal cir­cum­s­tances and the deter­mi­na­ti­on or eva­lua­ti­on of the sys­tem risk for each hazard as well as the deri­va­ti­on of sui­ta­ble risk reduc­tion measures.

The results of the safe­ty ana­ly­zes are docu­men­ted in a hazard log.

Rele­vant ope­ra­ting and envi­ron­men­tal influen­ces, the safety-relevant appli­ca­ti­on con­di­ti­ons, as well as gene­ral working and appli­ca­ti­on con­di­ti­ons of tech­no­lo­gy and peo­p­le are considered.

The out­line pro­po­sed in EN 50129 is pro­ven for struc­tu­ring the safe­ty case, espe­ci­al­ly for rail­way applications.

safety case railway applications en 50129 structure chapter document

The respon­si­bi­li­ties for the RAMS manage­ment tasks in the life cycle depend on the respec­ti­ve RAMS phase. The operator/client bears the main respon­si­bi­li­ty for the first life cycle pha­ses up to and inclu­ding the deter­mi­na­ti­on of the sys­tem requi­re­ments, wher­eby the sup­pli­er, who, like the ope­ra­tor, has to start a com­pre­hen­si­ve risk ana­ly­sis in phase 3, must be invol­ved in this pro­cess at an early stage.

The respon­si­bi­li­ty of the sup­pli­er beg­ins with the archi­tec­tu­re and appor­ti­onment of the sys­tem requi­re­ments and ends with the sys­tem accep­tance, from which it chan­ges back to the ope­ra­tor and appli­es until decommissioning.

Depen­ding on the type and scope of the pro­ject and the tech­ni­cal sys­tem, there are other par­ties invol­ved in this pro­cess (e.g. inde­pen­dent experts and super­vi­so­ry authorities).

Sub­con­trac­tors and sup­pli­ers have simi­lar tasks to those of the main contractor. 

The fol­lo­wing tasks and acti­vi­ties of the RAMS manage­ment are par­ti­cu­lar­ly note­wor­t­hy:

  • Exe­cu­ti­on and con­so­li­da­ti­on of all rele­vant RAMS-related pro­ject activities 
  • Assig­ning RAMS-related tasks to the indi­vi­du­al mem­bers of the pro­ject team
  • For­ma­ti­on of expert teams (e.g. for FMEAs)
  • Coor­di­na­ti­on of sub­tasks bet­ween main and subcontractor 

What are the benefits of a strict RAMS management
according to EN 50126?

With a con­sis­tent imple­men­ta­ti­on of the RAMS manage­ment pro­cess in accordance with the spe­ci­fi­ca­ti­ons of EN 50126, a mini­miza­ti­on of the hazards and faults cau­sed by the sys­tems to be deve­lo­ped and used is ulti­m­ate­ly achieved.

In detail, suppliers and operators can achieve the following benefits depending on their areas of responsibility:
    • Ful­fill­ment of the spe­ci­fi­ca­ti­ons for the RAMS pro­cess wit­hout unneces­sa­ry use of resources
    • appro­pria­te con­side­ra­ti­on of safety-related aspects
    • effi­ci­ent management
    • Opti­miza­ti­on of main­ten­an­ce stra­te­gies and sto­cking of spare parts
    • Secu­red cost plan­ning and jus­ti­fi­ca­ti­on of RAMS-related bud­gets and investments
    • Important pre­re­qui­si­te for cer­ti­fi­ca­ti­on as to ISO/TS 22163 is ful­fil­led with RAMS-Management
    • Com­pa­ra­bi­li­ty and pro­cess transparency

What is the position of the RAMS standard EN 50126 on the Common Safety Methods (CSM-RA)?

The risk assess­ment pro­ce­du­re accor­ding to EU Regu­la­ti­ons 2015/1136 and 402/2013 (CSM-RA) must be appli­ed for safety-relevant chan­ges to rail­way sys­tems (tech­ni­cal chan­ges, orga­niza­tio­nal mea­su­res and chan­ges to regulations).

Tech­ni­cal chan­ges to a sys­tem that are imple­men­ted with the RAMS manage­ment pro­cess of the CENELEC stan­dard EN 50126 and the rele­vant stan­dards for sub­sys­tems (e.g. EN 50129/ EN 50128) are gene­ral­ly con­form to the CSM procedure.

Project Examples and References

For more than 20 years, we have been pro­vi­ding evi­dence and ana­ly­ses for all areas of rail­way appli­ca­ti­ons on behalf of our customers.

The spec­trum of orders ran­ges from the simp­le FMEA for sup­pli­ers to the long-term assump­ti­on of RAMS manage­ment for various rail­way tech­no­lo­gy trades in the Gott­hard Base Tun­nel and Ceneri Base Tun­nel projects.

Find out about our references!