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

CLEARSY is upgrading a safety system for the Marseille subway

13 February 2026 | Railway

CLEARSY has begun work on a new contract with the Régie des Transports Métropolitains (RTM) of Marseille to upgrade the […]

CLEARSY equips ECOTRAIN with a latest-generation communication system between the track and the train

10 February 2026 | ERTMS

Several light rail projects, such as ECOTRAIN, unveiled at the end of 2025, are emerging. In this context, CLEARSY innovates […]

Training: CLEARSY has once again been awarded Qualiopi certification

5 February 2026 | Company

The Qualiopi quality certification has been awarded by AFNOR to CLEARSY for the following category: Training activities. This recognition enables […]

CLEARSY supervises smoke extraction for the new Line C of the Toulouse Metro.

3 February 2026 | Fire safety

CLEARSY is developing the smoke extraction supervision system for the new Line C of the Toulouse metro. CLEARSY supplies EIFFAGE […]

How can Artificial Intelligence and railway safety be reconciled?

30 January 2026 | R&D

Software safety analyses require knowledge of their algorithms, while Machine Learning (ML) models remain software ‘black boxes’. However, there is […]