Abstract. Component-Based Software Engineering (CBSE) is one of the approaches to master the development of large scale software. In this setting, the verification concern is still a challenge. The current work addresses the composability of components and their services. A component model (Kmelia) is introduced; an associated formalism, simple but expressive is introduced; it describes the services as extended LTSs and their structuring as components. The composability of components is defined on the basis of the composability of services. To ensure the correctness of component composition, we check that an assembly is possible via the checking of the composability of the linked services, and their behavioural compatibility. In order to mechanize our approach, the services and the components are translated into the Lotos formalism. Finally the Lotos CADP toolbox is used to perform experiments.

Abstract. In this paper, we present a generic approach to integrate datatypes expressed using formal specification languages within state diagrams. Our main motivations are (i) to be able to model dynamic aspects of complex systems with graphical user-friendly languages, and (ii) to be able to specify in a formal way and at a high abstraction level the datatypes pertaining to the static aspects of such systems. The dynamic aspects may be expressed using state diagrams (such as UML or SDL ones) and the static aspects may be expressed using either algebraic specifications or state oriented specifications (such as Z or B). Our approach introduces a flexible use of datatypes. It also may take into account different semantics for the state diagrams.

16 p.International audienceThe Kmelia abstract component model is extended to allow the description of component compositions with multipart interactions leading to simultaneous communications between more than two services. Shared services are defined to explicitly control multipart interactions. Accordingly the communication actions of \kmelia are extended. The formal definitions of the \kmelia model, the composition of components via their services and their analysis are revisited to integrate the extension of the model. An example illustrates the need and the usage of shared services

The imprecision of the definitions of UML2.0 sequence diagrams, given by the Object Management Group (OMG), does not allow the obtention of all the possible valid behaviours for a given distributed system, when communicating objects are independent. We choose the causal semantics, which is suitable for this kind of systems; we propose its extension to support complex behaviours, expressed with combined fragments. We propose the implementation of our approach with Event-B in order to check later on some properties of safety, liveness and fairness.