Virginie Wiels

The Landing Gear System Case Study

This document presents a landing gear system. It describes the system and provides some of its requirements. We propose this case study as a benchmark for techniques and tools dedicated to the verification of behavioral properties of systems.

Toward a wider use of formal methods for aerospace systems design and verification

Nowadays, it is well accepted that the development of critical systems involves the use of formal methods. One of the major fields where these methods made a lot of progress are the avionics, aerospace and more generally transport areas. Several methods, tools and techniques have been applied for the development of such systems in different parts of the world, and they have been actually put into practice during the development of specific aircraft programs. The aim of this introductory article and of this STTT special issue is to propose a brief overview of the state-of-the-art of current researches in formal methods applied to the development of avionics and aerospace systems and more broadly to take stock of the integration of formal methods in the aerospace industry.

ABZ 2014: The Landing Gear Case Study

This paper describes the modeling, done using the Event-B notation, of the aircraft landing gear case study that is proposed in a special track of the ABZ’2014 Conference. In the course of our development, we discovered some problems in our initial modeling approach. This has led us to propose a second approach and then a third one. Each approach is more efficient than the previous one in terms of proof obligations (roughly speaking: 2000, 1000, 500). All this will be described in this paper. We also try to go beyond this specific case study and give some thoughts about large industrial modeling.

The landing gear case study: challenges and experiments

Embedded critical systems need to be validated very thoroughly; it usually results in very long and onerous test phases. Formal techniques, in particular formal specification languages and associated proof tools, could be an advantageous alternative, or at least a good complement and allow a significant reduction of test phases. However, for these techniques to be used in practice, one issue to consider is their efficiency and scalability on complex industrial systems.Case studies have played an essential role in the history of formal methods. They have allowed to illustrate the application of formal techniques for modelling and verification, to compare different methods in terms of expressivity, performance and easiness of use. They have also permitted to enact the progress made by these methods.Dagstuhl seminar 9523 is about the famous Steam Boiler case study in 1995 had a lot of impact on the formal methods community. This case study allowed the assessment of formal techniques, the comparison of different formal techniques, the identification of areas for future work.

Thematic track: formal languages and methods for designing and verifying complex embedded systems

Nowadays, it is well accepted that the develop- ment of critical systems involves the use of formal methods. One of the major fields where these methods made a lot of progress are the avionics, aerospace, transport areas, telecom, etc. These systems are responsible for various functions, such as navigation, guidance, stability, power management, board/ground communications, passenger entertainment.... Moreover, their complexity is continuously growing.

Formal Modelling of Avionics Systems. An Approach Based on Category Theory and the EXPRESS Modelling Language

In previous work, we defined a component oriented framework dedicated to the specification of embedded systems in the aeronautics domain. A component is defined as a formal entity with three internal layers together with a collection of models defined in domain-oriented views. A categorical framework has been proposed to provide a unified representation of the component calculus as well as the various formal models used for the analysis of the system. In this paper, we present an implementation of this categorical framework using the EXPRESS data modelling language. EXPRESS is used to give an operational representation of the formalization, which is quite different from classical implementations of category theory based approaches.

Un cadre formel pour la spécification multivue de systèmes avioniques

This paper presents a component oriented framework dedicated to the specification of embedded systems in the aeronautics domain. A component is defined as a formal entity with three internal layers (hardware, operating system, applicative functions) together with a collection of models defined in different domain-oriented views. A categorical and institutional framework is proposed to provide a unified representation of the component calculus as well as the various formal models used for the analysis of the system. The framework and associated methodology are illustrated on a case study.