Mireille Larnac

Formal Representation and Proof of the Interpreted Sequential Machine Model

The Interpreted Sequential Machine (ISM) model handles a new approach for modeling and formal verification of discrete complex systems.

Temporal and Functional Verification of a Symbolic Representation of Complex Systems

The complexity of systems requires that validation methods are set in the designing phase as well as during their use or maintenance. We propose a modelling approach of the system which allows us to bring into play some methods for the validation of temporal and functional properties. The model that we have defined, called Interpreted Sequential Machine, is based on the concept of Sequential Machine and avoids the main limitation (combinatorial explosion of the number of states when introducing any new data) by separating the purely sequential part of the system from the data and the operations on the data. The validation of the complex system thus modelled consists in: expressing the behaviour of the system by a set of symbolic, logicotemporal formulAE, carrying out automatic proof procedures on these formulAE.

Temporal logics for analyzing the behavior of systems

The task of anticipating the behavior of a system requires to have a model as a basis for reasoning. This statement raises several questions and problems, especially concerning the knowledge the user has got of the system, and his ability to describe the aspects of the system he wants to study. This point also involves that some models are available, and consequently, that some associated methods for predicting the future evolution exist. Furthermore, the description or modeling is sometimes reduced to an observation of the reactions of outputs when inputs are applied, or can be more detailed. Moreover, there exists a large range of ways to handle and represent the “time” factor. The choice can be determining for the possible reasoning processes. This paper discusses these aspects and presents a particular solution for systems described from a discrete time point of view.

Simplification of Proof Procedures Based on the Path Condition Concepts

The formal proof of properties of a system first requires the expression of the behavior of the system into a formal language.

User defined multi-criteria added-value for enterprise processes analysis

Managers need to model and analyze the enterprise processes from different points of view in order to measure their efficiency. The paper focuses on an enterprise modeling approach allowing us to describe and analyze the influence of an activity in a process. The modeling method is based on the definition of a set of criteria related to the users efficiency estimators. The analysis is decomposed into three levels allowing us to qualify qualitatively and quantitatively the studied process.

Temporal proof of the behavior of sequential machines

The methodology presented in this paper concerns formal modeling and verification of discrete systems. Indeed, the behavior of a system, which needs to be analyzed, is described thanks to a finite state machine based model. Translating the behavior of such a model into a formal system then allows us to carry out some proofs of properties. In order to take time into account, temporal logic has been chosen. Using this formal framework, it is possible to formally manipulate a set of temporal logic formulae which represent the system in order to verify that the system fulfils some requirements (concerning security, quality, etc.) which can be expressed as temporal logic formulae. It has been necessary to develop a formal tool for proving some of these properties which need to study the influence of the present situation on the future evolution of the system: the Temporal Boolean Difference.

Modelling and Analysis of Complex Industrial Systems

Abstract This paper presents an approach well-suited to model and analyse behaviour of complex industrial systems confronted with hazardous events. An industrial complex system (process or factory organisation) is described using several entities and relations. The obtained model will be translated into Petri Nets for structural analysis and into Interpreted Sequential Machine for verifying temporal and dynamic properties. This composite approach has been developed within a common research project for the control of hazardous events in production systems.

Integrated and Reactive Part Routing Policies for Manufacturing Systems

Abstract This paper presents a new approach for modelling and formal analysis of discrete complex systems. The problematics addressed by this methodology concerns the analysis of complex systems, such as industrial production cells, or the organisation of production processes within an industrial plant. This approach is based on the collaboration of the Interpreted Sequential Machine (ISM) and a user-friendly description model (CANVAS Model).