Thierry Lecomte

Thierry Lecomte
ClearSy System Engineering

Engineer

About

51
Publications
11,788
Reads
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370
Citations
Introduction
I am currently in charge of R&D at CLEARSY, French SME specialized in safety critical systems. My activities are related to the development of formal/formally proven CASE tools, formal modelling and data / configuration validation. https://orcid.org/0000-0001-8977-4827
Featured research
Chapter
Full-text available
The railways have a quite long modelling history, covering many technical aspects from infrastructure to rolling stock, train movement, maintenance, etc. These models are mostly separate and operated independently by various stakeholders and with diverse objectives. This article presents some of the various digital modelling activities, including formal ones, that are undertaken by the railway industry, for design, development, validation, qualification, and exploitation. It also introduces trends toward regrouping models to obtain more significant results together with a larger scope, prefiguring digital twins.
Article
Full-text available
The CLEARSY Safety Platform (CSSP) was designed to ease the development of safety critical systems and to reduce the overall costs (development, deployment, and certification) under the pressure of the worldwide market. A smart combination of hardware features (double processor) and formal method (B method and code generators) was used to produce a SIL4-ready platform where safety principles are built-in and cannot be altered by the developer. Summarizing a 5-year return of experience in the effective application in the railways, this article explains how this approach is a game-changer and tries to anticipate the future of this platform for safety critical systems. In particular, the education of future engineers and the seamless integration in existing engineering processes with the support of Domain Specific Languages are key topics for a successful deployment in other domains. DSL like Robosim to program mobile robots and relay circuits to design railway signalling systems are connected to the platform.
Preprint
Full-text available
Industrial applications involving formal methods are still exceptions to the general rule. Lack of understanding, employees without proper education, difficulty to integrate existing development cycles, no explicit requirement from the market, etc. are explanations often heard for not being more formal. Hence the feedback provided by industry to academics is not as constructive as it might be. Summarizing a 25-year return of experience in the effective application of a formal method - namely B and Event-B - in diverse application domains (railways, smartcard, automotive), this article makes clear why and where formal methods have been applied, explains the added value obtained so far, and tries to anticipate the future of these two formalisms for safety critical systems.
Preprint
Full-text available
The CLEARSY Safety Platform (CSSP) was designed to ease the development of safety critical systems and to reduce the overall costs (development, deployment, and certification) under the pressure of the worldwide market. A smart combination of hardware features (double processor) and formal method (B method and code generators) was used to produce a SIL4-ready platform where safety principles are built-in and cannot be altered by the developer. Summarizing a 5-year return of experience in the effective application in the railways, this article explains how this approach is a game-changer and tries to anticipate the future of this platform for safety critical systems. In particular, the education of future engineers and the seamless integration in existing engineering processes with the support of Domain Specific Languages are key topics for a successful deployment in other domains. DSL like Robosim to program mobile robots and relay circuits to design railway signalling systems are connected to the platform.
Additional affiliations
October 2012 - present
ClearSy System Engineering
Position
  • BWare
Description
  • This project is aimed at providing a mechanized framework to support the automated verification of proof obligations coming from the development of industrial applications using the B method.
October 2012 - present
ClearSy System Engineering
Position
  • DEPARTS
Description
  • Design Patterns for Real-Time and Safe Applications. Enable an easier system-level certification. Project funded by French Government: "Investissement d'Avenir - Briques génériques du logiciel embarqué"
May 2011 - present
ClearSy System Engineering
Position
  • Cercles-2
Description
  • Proof of composition of SCADE/LUSTRE models with B / Event-B. Development of a generic, retargetable proof obligation generator.
Education
September 1988 - August 1989
Université de Technologie de Compiègne
Field of study
  • Pattern Recognition, Artificial Intelligence
September 1985 - August 1989
IMT Lille Douai
Field of study
  • Robotics

Publications

Publications (51)
Chapter
Full-text available
The railways have a quite long modelling history, covering many technical aspects from infrastructure to rolling stock, train movement, maintenance, etc. These models are mostly separate and operated independently by various stakeholders and with diverse objectives. This article presents some of the various digital modelling activities, including f...
Chapter
During the last five years, Event-B formal modelling has been successfully applied to various railway systems to demonstrate safety early in the design process or once systems are in operation. This approach is aimed at formalising a safety reasoning instead of modelling every bit of the system. This approach is intrinsically fit to scale up to lar...
Chapter
The CLEARSY Safety Platform (CSSP) is both a hardware and software platform aimed at developing safety critical applications. A smart combination of hardware features (double processor) and formal method (B method and code generators) was used to produce a SIL4-ready platform where safety principles are built-in. A first version, SK0, was released...
Chapter
The B-Method has an interesting history, where language and tools have evolved over the years. This not only led to considerable research and progress in the area of formal methods, but also to numerous industrial applications, in particular in the railway domain. We present a survey of the industrial usage of the B-Method since the first toolset i...
Chapter
Industrial applications involving formal methods are still exceptions to the general rule. Lack of understanding, employees without proper education, difficulty to integrate existing development cycles, no explicit requirement from the market, etc. are explanations often heard for not being more formal. This article reports some experience about a...
Article
Full-text available
The CLEARSY Safety Platform (CSSP) was designed to ease the development of safety critical systems and to reduce the overall costs (development, deployment, and certification) under the pressure of the worldwide market. A smart combination of hardware features (double processor) and formal method (B method and code generators) was used to produce a...
Chapter
The CLEARSY Safety Platform (CSSP) is aimed at easing the development and the deployment of safety critical applications, up to the safety integrity level 4 (SIL4). It relies on the smart integration of the B formal method, redundant code generation and compilation, and a hardware platform that ensures a safe execution of the software. This paper e...
Preprint
Full-text available
Developing safety critical applications often require rare human resources to complete successfully while off-the-shelf block solutions appear difficult to adapt especially during short-term projects. The CLEARSY Safety Platform fulfils a need for a technical solution to overcome the difficulties to develop SIL3/SIL4 system with its technology base...
Preprint
Full-text available
Industrial applications involving formal methods are still exceptions to the general rule. Lack of understanding, employees without proper education, difficulty to integrate existing development cycles, no explicit requirement from the market, etc. are explanations often heard for not being more formal. Hence the feedback provided by industry to ac...
Preprint
Full-text available
Industrial applications involving formal methods are still exceptions to the general rule. Lack of understanding, employees without proper education, difficulty to integrate existing development cycles, no explicit requirement from the market, etc. are explanations often heard for not being more formal. This article reports some experience about a...
Preprint
Full-text available
The CLEARSY Safety Platform (CSSP) was designed to ease the development of safety critical systems and to reduce the overall costs (development, deployment, and certification) under the pressure of the worldwide market. A smart combination of hardware features (double processor) and formal method (B method and code generators) was used to produce a...
Article
Full-text available
A Revolution for developing of safety critical application Developing safety critical applications often requires rare human resources to complete successfully while off-the-shelf block solutions appear difficult to adapt especially during short-term projects. Developed during the R&D project FUI LCHIP[5], the CLEARSY Safety Platform fulfills a nee...
Conference Paper
Full-text available
Industrial applications involving formal methods are still exceptions to the general rule. Lack of understanding, employees without proper education, difficulty to integrate existing development cycles, no explicit requirement from the market, etc. are explanations often heard for not being more formal. This article reports some experience about a...
Presentation
Full-text available
Presentation of the Ate lier B proof system: - intro to the B method - proof system - improvements given at the occasion of the Escola de Informática Teórica e Métodos Formais (ETMF) (http://www.sbmf2018.ufba.br/)
Chapter
Full-text available
Developing safety critical systems is a very difficult task. Such systems require talented engineers, strong experience and dedication when designing the safety principles of these systems. Indeed it should be demonstrated that no failure or combination of failures may lead to a catastrophic situation where people could be injured or could die beca...
Conference Paper
Full-text available
Industrial applications involving formal methods are still exceptions to the general rule. Lack of understanding, employees without proper education, difficulty to integrate existing development cycles, no explicit requirement from the market, etc. are explanations often heard for not being more formal. Hence the feedback provided by industry to ac...
Book
This volume constitutes the proceedings of the Second International Conference on Reliability, Safety and Security of Railway Systems, RRSRail 2017, held in Pistoia, Italy, in November 2017. The 16 papers presented in this volume were carefully reviewed and selected from 34 submissions. They are organized in topical sections named: communication ch...
Presentation
Full-text available
What happened with B and Atelier B during its 20-year life - from industry point of view
Conference Paper
We describe INTO-CPS, a project that aims to realise the goal of integrated tool chains for the collaborative and multidisciplinary engineering of dependable Cyber-Physical Systems (CPSs). Challenges facing model-based CPS engineering are described, focussing on the semantic diversity of models, management of the large space of models and artefacts...
Conference Paper
Full-text available
Safety-critical systems and software require particular care when their parameters have to be verified and validated, as any mistake may lead to a catastrophic scenario during their operating use. A recent technique, called formal data validation, enables an improvement in the level of confidence of the verifica-tion/validation process by associati...
Book
This book constitutes the refereed proceedings of the 19th Brazilian Symposium on Formal Methods, SBMF 2016, which took place in Natal, Brazil, in November 2016. The 12 papers presented together with two invited talks were carefully reviewed and selected from 22 submissions. They are organized in the following topical sections: analysis and verifi...
Book
This book constitutes the refereed proceedings of the First International Conference on Reliability, Safety, and Security of Railway Systems, RSSRail 2016, held in Paris, France, in June 2016. The 15 revised full papers presented were carefully reviewed and selected from 36 initial submissions. The papers cover a wide range of topics including fai...
Conference Paper
Full-text available
This paper reports on the use of formal techniques to ensure as far as possible a safe decommissioning of a plant several decades after it was designed and built. Combination of supervised learning, formal modelling, model animation and model checking enabled the recovery of an almost lost specification and the design of a virtual supervision syste...
Conference Paper
Full-text available
In this talk we describe a multi-platform code generator for the B method. In particular, we present a translation procedure from a large subset of the B language for implementations towards LLVM source code. This translation is defined formally as a set of rules defined recursively on the abstract syntax for B implementations. It already handles m...
Chapter
The B method was introduced at the end of the 1980s to produce software that is correct by construction. This chapter discusses the uses of B method for control-command systems for controlling platform doors of metro trains, and safety of microelectronic components. For several years now, the RATP in France has used platform doors on metro platform...
Chapter
Atelier B has been used on many occasions in developing safety programs that are used for functions at the SSIL3 and SSIL4 levels. The RIMEL project7 involved the development of an automatic refinement tool known as B automatic refinement tool (BART), specifically designed for integration into Atelier B. The code generation phase is critical, as a...
Conference Paper
Full-text available
Refining a B specification into an implementation can be a complex and time consuming process. This process can usually be separated in two distinct parts: the specification part, where the refinement is used to introduce new properties and specification details, and the implementation, where refinement is used to convert a detailed B specification...
Article
Full-text available
This article presents industrial experience of validating large data sets against specification written using the B / Event-B mathematical language and the ProB model checker.
Article
Full-text available
For a long time, formal methods have ignored floating-point computations. About ten years ago this has changed, and today specification languages and tools are in use in research and preindustrial contexts. Better late than never: the B method, which has been the first formal method to prove real-size software, will soon be able to prove the correc...
Conference Paper
Full-text available
This article presents industrial experience of applying the B formal method in the industry, on diverse application fields (railways, automotive, smartcard, etc.). If the added value of such an approach has been demonstrated over the year, using a formal method is not the panacea and requires some precautions when introduced in an industrial develo...
Conference Paper
Full-text available
In this article we would like to present some recent applications of the B formal method to the development of safety critical system. These SIL3/SIL4 1 compliant systems have their functional specification based on a formal model. This model has been proved, guaranteeing a correct by construction behaviour of the system in absence of failure of it...
Conference Paper
Full-text available
In this article we would like to present some recent applications of the B formal method to the development of safety critical systems, namely platform screen door controllers. These SIL3/SIL4 1 compliant systems have their functional specification based on a formal model. This model has been proved, guaranteeing a correct by construction behaviour...
Article
Proving system properties such as fail-safety is a challenge for systems engineering since industrial automation is nowadays embedding intensive on-site and remote infotronics components engineered with increasing intuitive ease-of-use techniques. Since a fonnal proof of the complete safe-behaviour of the resulting ad-hoc system is not possible, th...
Chapter
The approach presented in this book relies on the unification of System specification environments for developing electronic Systems that are formally proven to be correct (correct-by-construction Systems). The key concept conveyed is the formal proof of System properties, which is carried out at every phase of the co-design cycle. The main idea is...
Chapter
Event B aims at providing a way to model Systems [1][2] that they are made of many parts interacting with a highly evolving (and sometimes hostile) environment. They also quite often involve several concurrent executing agents. They require a high degree of correctness. Finally, most of them are the result of a construction process which is spread...
Chapter
When specifying a system, the refinement process of the B method enables (inner part) and the interface (outer part) of a component, from its abstraction to its implementation, while verifying, by proof at each refinement step, that there is no contradiction between two successive refinement levels
Chapter
This chapter begins with an introduction to the main concepts of formal methods. Languages and tools for developing formal System modeis are also described, while the use of semi formal notations and their integration with formal methods is covered as well. At the end of the chapter, an overview of the current Status of formal methods in embedded S...
Article
This book presents the perspective of the project on a Paradigm Unifying System Specification Environments for proven Electronic design (PUS SEE) as conceived in the course of the research during 2002 -2003. The initial statement of the research was formulated as follows: The objective of PUSSEE is to introduce the formal proof of system properties...
Article
This article presents work related to event driven B that has been undertaken by ClearSy, in close collaboration with J.R. Abrial and Louis Mussat (DCSSI)
Article
Full-text available
ClearSy, in close collaboration with J.R. Abrial and Louis Mussat (DCSSI). The main objective has been to verify suitability of B for system modelling. Most of these activities have been funded by MATISSE project (IST-1999-11435).

Network

Cited By

Projects

Projects (3)
Archived project
www.amass-ecsel.eu : AMASS will create and consolidate the de-facto European-wide open tool platform, ecosystem, and self-sustainable community for assurance and certification of Cyber-Physical Systems (CPS) in the largest industrial vertical markets including automotive, railway, aerospace, space, energy. The ultimate goal of AMASS is to lower certification costs for CPS in face of rapidly changing features and market needs. This will be achieved by establishing a novel holistic and reuse-oriented approach for architecture-driven assurance (fully compatible with standards such as AUTOSAR and IMA), multi-concern assurance (for co-analysis and co-assurance of e.g. security and safety aspects), and for seamless interoperability between assurance and engineering activities along with third-party activities (e.g. external assessments and supplier assurance).”
Project
LCHIP will provide a complete IDE able to automatically generate and prove bounded complexity software, and a low cost, safe execution platform, based on redundant PIC32 microcontrollers. A first public version of the complete environment is planned for Q3 2017.
Archived project
The aim of INTO-CPS project is to create an integrated “tool chain” for comprehensive Model-Based Design (MBD) of Cyber-Physical Systems (CPSs). The tool chain will support the multidisciplinary, collaborative modelling of CPSs from requirements, through design, down to realisation in hardware and software. This will enable traceability at all stages of the development.