Assembly of components based on interface automata and {UML} component model

International audienceWe propose an approach which combines component UML model and interface automata in order to assemble components and to verify their interoperability. We specify component based system architecture with component UML model, and component interfaces with interface automata. Interface automata is a common Input Output (I/O) automata-based formalism intended to specify the signature and the protocol level of component interfaces. We improve interface automata approach by component UML model, in order to consider system architecture, in component composition and interoperability verification methods. Therefore, we handle in interface automata, the connection between components, and the hierarchical connections between composite components and their subcomponents

Spécification et Validation d'un Contrôleur de Performances Sportives

International audienceCe papier a pour objectif de montrer l'intérêt d'utiliser les méthodes formelles pour spécifier et valider un système médical, nous utilisons les automates hiérarchiques pour modéliser ces systèmes. La sémantique utilisée est celle d'une structure de Kripke où les états sont valués par des propositions atomiques. Cette structure peut être de grande taille en nombre d'états. Par nature, les systèmes hiérarchiques sont définis de manière hiérarchique par un ensemble de sous systèmes en éclatant à chaque fois un ou plusieurs états en un ensemble d'automates. Dans cet article, nous proposons de vérifier des proporiétés, seulement sur ces sous-systèmes. Pour pallier au problème de l'explosion combinatoire et la vérification de propriétés, nous considérons que les sous systèmes concernés par la propriété à vérifier et en déduire sa vérification sur le système global. Les résultats sont illustrés sur l'exemple d'un contrôleur de performances sportives

Politiques d'adaptation pour la reconfiguration du composant de localisation

International audienceLes approches à base de composants sont intensivement étudiées dans le cadre des systèmes complexes. Ces approches visent à concevoir des systèmes et des applications par assemblage de composants préfabriqués, réutilisables et faciles à maintenir. Afin de répondre à des besoins spécifiques, une des approches est l'utilisation de politiques d'adaptation permettant de reconfigurer dynamiquement le modèle à composants par rapport au contexte de son environnement. Le travail présenté dans cet article repose sur un cadre formel permettant de décrire des politiques d'adaptation appliquées à un composant de localisation. Ce composant, que nous spécifions en Fractal, permet de fournir une position optimale, obtenue à partir de plusieurs positions fournies par plusieurs systèmes de localisation (GPS, Wifi). Nous définissons deux politiques d'adaptation pour ce composant et simulons son fonctionnement sur une extension de Fractal. Suite aux expérimentations, nous proposons une extension des politiques d'adaptation pour prendre en compte de nouveaux aspects non fonctionnels

Refinement of Interface Automata Strengthened by Action Semantics

International audienceInterface automata are light-weight models that capture the temporal interface behavior of software components. They have the ability to model both the input requirements and the output behavior of a component. They support the compatibility check between interface models to ensure a correct interaction between components and they adopt an alternating simulation approach to design refinement. In this paper, we extend our previous works on checking interface automata interoperability by adapting their alternating refinement relation to the action semantics. We show the relation between pre and post-conditions of transitions in the abstract version of an interface and their corresponding ones in its concrete version. We illustrate our extensions by a case study of the CyCab car component-based system

Adaptation des Protocoles des Composants par les Automates d'Interface

National audienceUn des objectifs de l'ingénierie des logiciels base de composants (CBSE) est de permettre la réutilisation des composants sans affecter leurs implémentations. Pour atteindre cet objectif, il est nécessaire de proposer des méthodes et des outils d'adaptation des composants avec leur environnement lorsque des incompatibilités se produisent au cours de leurs interactions. Dans ce papier, nous proposons une approche formelle d'adaptation des composants dont les protocoles comportementaux sont décrits par les automates d'interface, fin d'éliminer les disparités entre les composants aux niveaux des signatures et des protocoles. L'approche proposée tire profit de l'approche optimiste des automates d'interface. Ce formalisme permet de spécifer l'ordonnancement temporel des services requis et offerts des composants

Incremental Verification of Component-Based Timed Systems

International audienceWe are interested in the incremental development, by integration of components, of component-based timed systems, and in particular, in the preservation of their properties during such a development process. We model timed components with timed automata. Their composition is achieved with the classic parallel composition operator for timed automata. The specifications of these timed systems are expressed with the timed linear logic Mitl (Metric Interval Temporal Logic). To guarantee the preservation of properties during an incremental development process, we propose to use ? -simulation relations, adapted for timed systems. First, we extend the classic notion of ? -simulation with timed aspects. As in the untimed case, this relation, called timed ? -simulation, preserves safety properties. To preserve more properties, in particular liveness ones, we present another relation, called divergencesensitive and stability-respecting (DS) timed ? -simulation. This last relation preserves all Mitl properties (and thus liveness ones), but also strong non-zenoness and deadlockfreedom. Moreover, as we put ourselves in a component-based framework, we study if the relations are appropriate to the use of the composition operator that we consider. For this purpose, we study if the relations are compatible with this operator, and if composability and compositionality hold. These three properties are a way to reduce the cost of the verification of the preservation, or even to get it for free. It results that the timed ? -simulation is appropriate with the classic operator since the properties hold without any assumption. However, this is not the case for the DS timed ? - simulation. We implemented the algorithmic verification of the simulations in a tool called Vesta (Verification of Simulation for Timed Automata). The structure of the tool was inspired from the one of the Open-Kronos tool. This allows, as additionnal feature, to connect the models considered in Vesta to the modules of the verification platform Open-Caesar. We show the interest of our method by applying it on a case study, concerning a production cell example

Adapting Components Behaviours using Interface Automata

International audienceOne of the principal goal of Component-Based Software Engineering (CBSE) is to allow the reuse of components in diverse situations without affecting their codes. To reach this goal, it is necessary to propose approaches to adapt a component with its environment when behavioural mismatches occur during their interactions. In this paper, we present a formal approach based on interface automata to adapt components in order to eliminate possible behavioural mismatches, and then insure more flexible interoperability between component

Mapping SysML to modelica to validate wireless sensor networks non-functional requirements

International audienceWireless Sensor Networks (WSN) have registered a large success in the scientific and industrial communities for their broad application domains. Furthermore, the WSN specification is a complex task considering to their distributed and embedded nature and the strong interactions between their hardware and software parts. Moreover, most of approaches use semi-formal methods to design systems and generally simulation to validate their properties in order to produce models without errors and conform to the system specifications. In this context, we propose a Model Driven Architecture (MDA) approach to improve the verification of the WSN properties. This approach combines the advantages of the System Modeling Language (SysML) and the Modelica language which promote the reusability and improve the development process. In this work, we specify a model transformation from SysML static, dynamic and requirement diagrams to their corresponding elements in Modelica. Thanks to the SysML requirement diagram which is transformed into Modelica properties (constraints), we propose a technique using dynamic tests to verify WSN properties. We have used the Topcased platform to implement our approach 1 and chosen a crossroads monitoring system which is based on wireless sensors to illustrate it. Besides, we have verified and validated some wireless sensors properties of the studied system

Preservation of timed properties during an incremental development by components

International audienceWe are interested in the preservation of local properties of timed components during their integration in a timed system. Timed components are modeled as timed automata or timed automata with deadlines. Properties considered are all safety and liveness properties which can be expressed with the timed linear logic Mitl (Metric Interval Linear Logic), as well as non-zenoness and deadlock-freedom. Integration of components is a kind of incremental development which consists in checking locally the properties of the components, before integrating them in the complete system, using some composition operator. Of course, established properties have to be preserved by this integration. Checking preservation can be achieved by means of the verification of timed tau-simulation relations. Composability, compatibility and compositionality of these relations w.r.t. composition operators are properties which allow to reduce the cost of this verification. We examine these properties when integration is achieved with two different timed composition operators: the classic operator usually taken for timed systems and which uses a CSP-like composition paradigm, and a non-blocking operator closer to the CCS paradigm

Assembling Components using SysML with Non-Functional Requirements

International audienceNon-functional requirements of component based systems are important as their functional requirements, therefore they must be considered in components assembly. These properties are beforehand specified with SysML requirement diagram. We specify component based system architecture with SysML block definition diagram, and component behaviors with sequence diagrams. We propose to specify formally component interfaces with interface automata, obtained from requirement and sequence diagrams. In this formalism, transitions are annotated with costs to specify non-functional property. The compatibility between components is performed by synchronizing their interface automata. The approach is explained with the example of the electric car CyCab, where the costs are associated to energy consumption of component actions. Our approach verifies whether, a set of components, when composed according to the system architecture, achieve their tasks by respecting their non-functional requirements