Operational safety critical software methods in railways

Abstract

Railway Signalling manufactures design Safety-Critical Software for around ten years. This software is crucial for Interlocking Systems and Speed Control Systems. The techniques used by the Railways and the manufacturers were dissimilar in the past because of the heterogeneous of signalling equipments and exploitation rules among the countries. Recently some efforts have been done at the European level to harmonize the processes and methods for cross acceptance of safety-critical software between nations. The works of the IRSE Technical committee and the CEN/CENELEC WG A1 are presented. Formal Specifications and Formal proofs seem to be considered as one of the good techniques to use in that field. Some of the systems that we have produced using them are presented.