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 accepted prior to the creation of this standard, but only to the extent and insofar as the new system with the new functionality is being integrated. It is otherwise not applicable to any unmodified aspects of the existing system; as far as reasonably practicable, to modifications and extensions of existing systems accepted prior to the creation of this standard, but only to the extent and insofar as existing systems are being modified. It is otherwise not applicable to any unmodified aspect 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, which remain unmodified. Railway applications means Command, Control & Signalling, Rolling Stock and Fixed Installations. Processes for the specification and demonstration of RAMS requirements are cornerstones of this standard. This European Standard promotes a common understanding and approach to the management of RAMS. The process defined by this European Standard assumes that railway duty holders and railway suppliers have business-level policies addressing Quality, Performance and Safety. The approach defined in this standard is consistent with the application of quality management requirements contained within the EN ISO 9001.