Abstract This paper describes the Event-B modeling of the landing gear system of an aircraft whose the complete description can be found in [3]. This real-life case study has been proposed by the ABZ’2014 track that takes place in Toulouse, the European capital of the aeronautic industry. Our modeling is based on the Parnas and Madey’s 4-Variable Model that permits to consider the different parts of a system. These parts are incremently introduced using the Event-B refinement technique. The entire development has been carried out under the Rodin toolset. To validate and prove the different components, we use the Atelier B, SMT and ML provers which are plugged to Rodin.
Abstract This paper presents a stepwise formal development of the landing system of an aircraft. The formal models include the complex behaviour, temporal behaviour and sequence of operations of the landing gear system. The models are formalized in Event-B modeling language, and then the ProB model checker is used to verify the deadlock freedom and to validate the behaviour requirements by animating the formalized models. This case study is considered as a benchmark for techniques and tools dedicated to the verification of behavioural properties of the complex critical systems.
Abstract The paper presents an Abstract State Machine (ASM) specification of the Landing Gear System case study, and shows how the ASMETA framework can be used to support the modeling and analysis (validation and verification) activities for developing a rigorous and correct model in terms of ASMs. We exploit the two fundamental concepts of the ASM method, i.e., the notion of ground model and the refinement principle, and we achieve model development and model analysis by the combined use of formal methods for specification and for verification.
Abstract Formal specifications are widely used in the development of safety critical systems, as the Sensor Voting Module of the Landing Gear System. However, the conformance relationship between the formal specification and the concrete implementation must be checked. In this paper, we show a technique to formally link a Java class with its Abstract State Machine formal specification, and two approaches for checking their conformance: an offline model-based testing approach and an online runtime monitoring approach.
Abstract A case study problem based on a set of aircraft landing gear is examined in Hybrid Event-B (an extension of Event-B that includes provision for continuously varying behaviour as well as the usual discrete changes of state). Although tool support for Hybrid Event-B is currently lacking, the complexity of the case study provides a valuable challenge for the expressivity and modelling capabilities of the formalism. The size of the case study, and in particular, the number of overtly independent subcomponents that the problem domain contains, both significantly exercise the multi-machine and coordination capabilities of Hybrid Event-B, requiring the use of novel coordination mechanisms.
Abstract In this paper we present our formalisation of the ABZ landing gear case study in Event-B. The development was carried out using the Rodin platform and mainly used superposition refinement to structure the specification. To validate the model we complemented proof with animation and model checking. For the latter, we used the ProB animator and model checker. Graphical representation of the model turned out to be crucial in the development and validation of the model; this was achieved using a new version of BMotion Studio integrated into ProB 2.0.
Abstract Distributed systems and applications are becoming increasingly complex, due to factors such as dynamic topology, heterogeneity of components, failure detection. Therefore, they require effective techniques for guaranteeing safety, security and convergence. The self-⋆ systems are based on the idea of managing efficiently complex systems and architectures without user interaction. This paper presents a methodology for verifying distributed systems and ensuring safety and convergence requirements: Correct-by-construction and service-as-event paradigms are used for formalizing the system requirements using incremental refinement in Event B. Moreover, this paper describes a mechanized proof of correctness of the self-⋆ systems along with a case study related to the P2P-based self-healing protocol.
Abstract The B method is a formal specification method and a means of formal verification and validation of safety-critical systems such as railway systems. In this short paper, we use the B4MSecure tool to transform the UML models, fulfilling requirements of European Railway Traffic Management System (ERTMS) operating rules, into B specifications in order to formally validate them.
Abstract Alloy is a formal modeling language based on first-order relational logic, with no native support for specifying reactive systems. We propose an extension of Alloy to allow the specification of temporal formulas using LTL, and show how they can be verified by bounded model checking with the Alloy Analyzer.
Abstract In Computer Networks, several studies show that 50 to 80% of infrastructure downtime is caused by misconfiguration [1]. Current approaches are aimed to check the configuration of each device and detect conflicts, inconsistencies and bugs, other approaches focus on the specification of the intended behaviour of a network and the automatic configuration of each one of its elements [2].