Composability, compatibility, compositionality: automatic preservation of timed properties during incremental development

We 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 τ -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. Key-words: τ -simulations, component-based timed systems, integration of components, preservation of timed linear properties. Laboratoire d’Informatique de l’Universite de Franche-Comte, UFR Sciences et Techniques, 16, route de Gray, 25030 Besancon Cedex (France) Telephone : +33 (0)3 81 66 64 55 — Telecopie : +33 (0)3 81 66 64 50 Composabilite, compatibilite, compositionnalite : preservation automatique de proprietes temporises durant un developpement incremental Resume : Nous nous interessons a la preservation des proprietes locales de composants temporises durant leur integration dans un systeme temporise. Ces composants temporises sont modelises par des automates temporises ou des automates temporises avec deadlines. Les proprietes que nous considerons sont toutes les proprietes de surete et de vivacite qui peuvent etre exprimees a l’aide de la logique MITL (Metric Interval Temporal Logic), ainsi que le non-zenonisme fort et les proprietes d’absence de blocages. L’integration de composants est un type de developpement incremental qui consiste a verifier localement les proprietes des composants, avant de les integrer au systeme complet, en utilisant un certain operateur de composition. Pour que cette demarche ait un interet en pratique, les proprietes etablies localement doivent etre preservees par l’integration. Cette preservation peut etre garantie par la verification de relations de τ -simulation temporisee. La composabilite, la compatibilite et la compositionnalite de ces relations vis-a-vis des operateurs de composition utilises pour l’integration sont des proprietes essentielles pour reduire le cout de cette verification. Nous examinons ici ces proprietes quand l’integration est effectuee avec deux operateurs de composition en particulier : l’operateur classique pour les automates temporises, utilisant un paradigme de composition a la CSP, et un operateur non bloquant, plus proche du paradigme de CCS. Mots-cles : τ -simulations, Systemes temporises a base de composants, integration de composants, preservation proprietes lineaires temporisees. Laboratoire d’Informatique de l’Universite de Franche-Comte, UFR Sciences et Techniques, 16, route de Gray, 25030 Besancon Cedex (France) Telephone : +33 (0)3 81 66 64 55 — Telecopie : +33 (0)3 81 66 64 50 Composability, compatibility, compositionality: automatic preservation of timed properties during incremental development Jacques Julliand, Hassan Mountassir, and Emilie Oudot LIFC Laboratoire d’Informatique de l’Universite de Franche-Comte 16, route de Gray, 25030 Besancon Cedex, France Ph:+33 (0)3 81 66 66 51, Fax:+33 (0)3 81 66 64 50 {julliand,mountass,oudot}@lifc.univ-fcomte.fr We 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 deadlockfreedom. 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 τ -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. Key-words. τ -simulations, component-based timed systems, integration of components, preservation of timed linear properties.