Val de Roissy

Development of SIL4 safety software for the fixed automatisms of the future Val de Roissy

Realization of the safety software with the B method

Siemens Transportation Systems (STS) has subcontracted with CLEARSY for the realization with B of the safety software for the automatisms of the future VAL de ROISSY: alarm control unit (UCA) and automatic section drivers (PADS) for Siemens.

This software represents approximately 150,000 ADA lines once completed. The software is classified as SIL4, according to standards IEC61508: EN50126, EN50128, EN50129.

A few figures

On the L1 VAL line inaugurated on 4th April 2007, 2 computers have been installed: the UCA and PADS (as many PADS as required – S for Section).

For the pads software:

• 186,440 lines for the AS Ada safety code (AS – Safety Application)
• 30,632 lines for the AS non safety-critical Ada code
• number of mathematical Proofs: 62,056
• number of B lines: 256,653 lines

For the UCA software:

• 50,085 lines for the AS Ada safety code
• 11,662 lines for the AS non safety-critical Ada code
• number of mathematical Proofs: 12,811
• number of B lines: 65,722 lines

The number of effective B lines is smaller than that announced as comments are taken into account, including remarks which guide refinement.

Publications and feedback

• Introduction document: article “using B as a high level programming language in an industrial project”
• Conférence ZB2005: présentation (transparents) “using B as a high level programming language in an industrial project”
• Météor: a successful application of B in a large project”, FM’99, Toulouse, France, 1999 – Behm P., Benoît P., Faivre A., Meynadier J.-M.
• VitalSoftware: formal method and coded processor – ERTS 2006 – 25-27 January 2006 – Toulouse – Dollé D.
• Formal Methods in Industry: achievements, Problems, Future – Jean Raymond Abrial Swiss Federal Institute of Technology Zurich