CLEARSY

Safety software and systems designer

The CLEARSY company

CLEARSY was founded on January 1, 2001 by the team of engineers responsible for the industrialisation of the formal modelling tool called Atelier B, used in the railway sector to produce safety software.

CLEARSY: safety systems engineering

We are a French SME, specialised in the realisation of safety systems and software from level SIL1 to SIL4. We develop complex systems by ensuring their design, their validation, verification and safety study, right up to their commissioning.

CLEARSY produces safe systems and software in the railway, automotive, military, space and nuclear fields.

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Presentation

News

Simulation for the ERTMS of the Future

4 June 2026 | ERTMS

As part of the ongoing development of the ERTMS standard, the European Union Agency for Railways (ERA) is studying the […]

Safe validation of railway track topology

4 June 2026 | Railway

To operate driverless metros at full capacity, it all starts… with data. The digital representation of the railway infrastructure creates […]

Tailor-made automatic train stop system

26 May 2026 | Offers

Stadler is supplying RATP with maintenance trains that must be fully compatible with the Paris network’s signaling system. The goal is to ensure the proper functioning of the automatic train stop system when trains pass through restricted signals, in order to enhance the safety of […]

Common Criteria standard: proving security through Formal Methods

25 May 2026 | Microelectronics

CLEARSY supports major companies in the microelectronics industry with certification under the Common Criteria, an international standard (ISO/IEC 15408) that serves as a […]