Implementation of the CENELEC EN 50128:2011 standard - software for rail transportation

Initially, the safety of rail systems was based on control of signalling. With automatic systems such as metros (see line 14 of the Paris metro and/or the VAL – automatic light vehicle – at Charles de Gaulle airport), software plays a key role in safety management. The 2001 version of the CENELEC EN 50128 standard was drawn up to define the context in which software safety can be managed. This version of the standard benefited from the commissioning of several software-based systems (SACEM, SAET-METEOR, etc.).

Since this version, use of the software has been extended to all parts of the rail industry (driver assistance, door management, traction management, sensor parameter management, etc.), and new issues such as maintenance and deployment had to be taken into account. Software maintenance is not just a question of correcting anomalies, but also of controlling the evolution of a whole range of equipment, which can be deployed in different systems.

The creation of a software application relies on the use of complex tools which can have an impact on the executable (code generators, compilers, etc.) and/or on verification (test environment, programming rule verification tool, etc.). This is why it is necessary to qualify the tools used. Note that this notion of qualification has been introduced in all the standards that have been updated (DO 178 : C, ISO 26262, IEC 61508).