BSI - PREN 50126-4
Railway applications - The Specification and Demonstration of Reliability, Availability, Maintainability and Safety (RAMS) - Part 4: Functional Safety - Electrical/Electronic/Programmable electronic systems
|Publication Date:||1 October 2012|
|ICS Code (Railway engineering in general):||45.020|
|ICS Code (Electric traction equipment):||29.280|
This part of EN 50126
• is intended to apply to all safety-related electronic (E/E/PE)
• is applicable to safety-related electronic systems (including sub-systems and hardware) for railway applications;
• is primarily applicable to systems/sub-systems/
- either that the hardware is not relied on for safety,
- or that the hardware can be relied on for those functions which relate to safety;
- to the specification, architecture, design, construction,
implementation, integration, manufacturing, installation,
acceptance, operation, maintenance and modification/extensi
- to generic sub-systems and hardware (both
• addresses railway specifics;
• does not define
- RAMS targets, quantities, requirements or solutions for specific railway applications
- rules or processes pertaining to the certification of railway products against the requirements of this standard
- an approval process by the safety authority;
• does not specify requirements for ensuring system security.
This part of EN 50126 is applicable
• to the specification and demonstration of safety for all railway applications and at all levels of such an application, as appropriate, from complete railway systems to major systems and to individual and combined sub-systems and hardware components within these major systems, including those containing software; in particular:
- to new systems
- to new systems integrated into existing systems in operation prior to the creation of this standard, although it is not generally applicable to other aspects of the existing system;
- for modifications of existing systems in operation prior to the creation of this standard, although it is not generally applicable to other aspects of the existing system.
- at all relevant phases of the life cycle of an application;
- for use by railway duty holders, railway suppliers, assessors and safety authorities.
Application of EN 50126-4 follows from SIL allocation to
NOTE Guidance on the applicability is given in the requirements of this standard.
Existing systems compliant with any version of former EN 50126, EN 50128 or EN 50129 shall not be subject of reconsideration and are considered as compliant with this standard.
Railway applications mean Command, Control & Signalling, Rolling Stock and Fixed Installations for Railways (e.g. Electric Power Supply).