This document is applicable to safety-related electrical, electronic and programmable electronic systems (E/E/PES including subsystems and equipment) for electrical railway signalling systems for railway systems within the scope of Directive (EU) 2016/798 , unless they can be excluded from the scope of that Directive in accordance with Article 2(2) thereof.
This pre-standard provides guidance on how to derive safety requirements for railway signalling functions using the semi-quantitative method "Risk Score Matrix" by
- the structure of the method is described,
- the necessary parameters are defined,
- an exemplary system definition for generic functions of railway signalling is carried out (Annex A)
- safety requirements for these functions are derived by means of the chosen method - taking into account relevant framework conditions - as examples (Annex B),
- it is proven that the requirements for the design and application of semi-quantitative methods according to DIN V VDE V 0831 101 (VDE V 0831 101) are fulfilled (Annex C)
This pre-standard is applicable to functions of a system for which safety requirements can be determined and implemented in the form of a Tolerable Hazard Rate (THR) and a Safety Integrity Level (SIL). This prestandard determines exemplary safety requirements for generic functions. The transferability of these safety requirements to generic systems, subsystems and equipment as well as to specific applications is given, provided that it can be demonstrated on a project/application-specific basis that the framework conditions specified in this pre-standard are met.