Requirements, Formal Verification and Model transformations of an Agent-based System: A CASE STUDY

One of the most challenging tasks in software specifications engineering for a multi-agent system is to ensure correctness. As these systems have high concurrency, often have dynamic environments, the formal specification and verification of these systems along with step-wise refinement from abstract to concrete concepts play major role in system correctness. Our objectives are the formal specification, analysis with respect to functional as well as non-functional properties by step-wise refinement from abstract to concrete specifications and then formal verification of these specifications. A multi-agent system is concurrent system with processes working in parallel with synchronization between them. We have worked on Gaia multi-agent method along with finite state process based finite automata techniques and as a result we have defined the formal specifications of our system, checked the correctness and verified all possible flow of concurrent executions of these specifications. Our contribution consists in transforming requirement specifications based on organizational abstractions into executable formal verification specifications based on finite automata. We have considered a case study of our multi-agent system to exemplify formal specifications and verification. Keywords: Multi-Agent System, Agent Models and Architecture, Gaia multi-agent method, Formal methods, Formal verification, Finite State Process (FSP), Labelled Transition System (LTS), Labelled Transition System Analyzer (LTSA), Safety property, Liveness propert

Requirements, Formal Verification and Model transformations of an Agent-based System: A CASE STUDY

One of the most challenging tasks in software specifications engineering for a multi-agent system is to ensure correctness. As these systems have high concurrency, often have dynamic environments, the formal specification and verification of these systems along with step-wise refinement from abstract to concrete concepts play major role in system correctness. Our objectives are the formal specification, analysis with respect to functional as well as non-functional properties by step-wise refinement from abstract to concrete specifications and then formal verification of these specifications. A multi-agent system is concurrent system with processes working in parallel with synchronization between them. We have worked on Gaia multi-agent method along with finite state process based finite automata techniques and as a result we have defined the formal specifications of our system, checked the correctness and verified all possible flow of concurrent executions of these specifications. Our contribution consists in transforming requirement specifications based on organizational abstractions into executable formal verification specifications based on finite automata. We have considered a case study of our multi-agent system to exemplify formal specifications and verification.Comment: 16 pages; Computer Engineering and Intelligent Systems http://www.iiste.org - ISSN 2222-1719 (Paper) ISSN 2222-2863 (Online) - Vol.5, No.3, 201

Generic Expression in B of the Influence/Reaction Model: Specifying and Verifying Situated Multi-Agent Systems

This paper addresses the formal specification and verification of situated multi-agent systems that can be formulated within the influence-reaction model as proposed in 1996 by Ferber & Muller. In this framework our objective is to prove the correctness of reactive multi-agent systems with respect to a certain formal specification or property, using formal methods. This is an important step to bring multi-agent systems to high quality standards as required for critical applications encountered in domains such as transport systems. A generic B writing of systems instantiating the influence reaction model is proposed, using patterns of specification. An illustration is then presented on the formal specification of a system operating electrical vehicles under precise automatic control at close spacings to form a platoon. The papers ends with considerations about further improvements of the framework, involving simulation and study of the properties of the system

Towards Validating a Platoon of Cristal Vehicles using CSP||B

24 pagesInternational audienceThe complexity of specification development and verification of large systems has to be mastered. In this paper a specification of a real case study, a platoon of Cristal vehicles is developed using the combination, named CSP||B, of two well-known formal methods. This large -- both distributed and embedded -- system typically corresponds to a multi-level composition of components that have to cooperate. We show how to develop and verify the specification and check some properties in a compositional way. We make use of previous theoretical results on CSP||B to validate this complex multi-agent system

Towards Validating a Platoon of Cristal Vehicles using CSP||B

24 pagesInternational audienceThe complexity of specification development and verification of large systems has to be mastered. In this paper a specification of a real case study, a platoon of Cristal vehicles is developed using the combination, named CSP||B, of two well-known formal methods. This large -- both distributed and embedded -- system typically corresponds to a multi-level composition of components that have to cooperate. We show how to develop and verify the specification and check some properties in a compositional way. We make use of previous theoretical results on CSP||B to validate this complex multi-agent system

Model checking multi-agent systems

A multi-agent system (MAS) is usually understood as a system composed of interacting autonomous agents. In this sense, MAS have been employed successfully as a modelling paradigm in a number of scenarios, especially in Computer Science. However, the process of modelling complex and heterogeneous systems is intrinsically prone to errors: for this reason, computer scientists are typically concerned with the issue of verifying that a system actually behaves as it is supposed to, especially when a system is complex. Techniques have been developed to perform this task: testing is the most common technique, but in many circumstances a formal proof of correctness is needed. Techniques for formal verification include theorem proving and model checking. Model checking techniques, in particular, have been successfully employed in the formal verification of distributed systems, including hardware components, communication protocols, security protocols. In contrast to traditional distributed systems, formal verification techniques for MAS are still in their infancy, due to the more complex nature of agents, their autonomy, and the richer language used in the specification of properties. This thesis aims at making a contribution in the formal verification of properties of MAS via model checking. In particular, the following points are addressed: • Theoretical results about model checking methodologies for MAS, obtained by extending traditional methodologies based on Ordered Binary Decision Diagrams (OBDDS) for temporal logics to multi-modal logics for time, knowledge, correct behaviour, and strategies of agents. Complexity results for model checking these logics (and their symbolic representations). • Development of a software tool (MCMAS) that permits the specification and verification of MAS described in the formalism of interpreted systems. • Examples of application of MCMAS to various MAS scenarios (communication, anonymity, games, hardware diagnosability), including experimental results, and comparison with other tools available