scope:

This part 1 of EN 50126 - considers RAMS, understood as reliability, availability, maintainability and safety and their interaction; - considers the generic aspects of the RAMS life-cycle. The guidance in this part is still applicable in the application of specific standards; - defines - a process, based on the system life-cycle and tasks within it, for managing RAMS; - a systematic process, tailorable to the type and size of system under consideration, for specifying requirements for RAMS and demonstrating that these requirements are achieved; - addresses railway specifics; - enables conflicts between RAMS elements to be controlled and managed effectively; - 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 1 of EN 50126 is applicable - to the specification and demonstration of RAMS 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 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; - to 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 and the railway suppliers. It is not required to apply this standard to existing systems including those systems already compliant with any version of former EN 50126, EN 50128 or EN 50129, which remain unmodified. Railway applications mean Command, Control & Signalling, Rolling Stock and Electric Power Supply for Railways (Fixed Installations). In this standard the term hardware refers to E/E/PE components or systems. If non E/E/PE hardware is meant, this is specifically mentioned.