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

Safety at the core of Interoperability – New York City subway, MTA

3 April 2026 | Railway

The Metropolitan Transportation Authority (MTA) has adopted the CLEARSY Data Solver ! In complex rail environments such as New York […]

CLEARSY enables ETCS upgrades to be tested before their actual deployment

2 April 2026 | ERTMS

In the European ETCS Level 2 rail system, train movements are supervised by control centers known as RBCs (Radio Block […]

CLEARSY RS4 safety relay is now even easier to integrate

24 March 2026 | Component

CLEARSY is evolving its range of SIL 4 certified safety relays (compliant with EN 50129). As safe and reliable as […]

Over 1,000 safety controllers deployed by CLEARSY

19 March 2026 | Component

The CLEARSY Safety Platform, based on a dual-core safety architecture, has just surpassed the milestone of 1,000 controllers deployed worldwide […]

CLEARSY at the ERTMS 2026 conference in Valenciennes

18 March 2026 | ERTMS

CLEARSY is a leading provider of simulation and testing tools compliant with ERTMS standards, not only for Baseline 3 but […]

Modernising nuclear control and command systems: CLEARSY and D3E at work at the CEA in Marcoule

12 March 2026 | Energy/nuclear

CLEARSY is assisting the CEA Marcoule in modernising the control system for the Basic Nuclear Installation (INB): Multipurpose Intermediate Storage […]