Section: Research Program

Service Composition

We are considering processes as pieces of software whose execution traverses the boundaries of organisations. This is especially true with service oriented computing where processes compose services produced by many organisations. We tackle this problem from very different perspectives. We try to find the best compromise between the need for privacy of internal processes from organisations and the necessity to publicise large part of them. To do that, we propose to distribute the execution and the orchestration of processes among the organisations themselves, and attempting to ensure non-functional properties in this distributed setting  [19]. Non-functional aspects of service composition relate to all the properties and service agreements that one wants to ensure. They are orthogonal to the actual business but they are important when a service is selected and integrated in a composition. This includes transactional context, security, privacy, and quality of service in general. Defining and orchestrating services on a large scale while providing the stakeholders with some strong guarantees on their execution is a first-class problem for us. For a long time, we have proposed models and solutions to ensure some properties (e.g. transactional properties) during process execution, either by design or by the definition of some protocols. We also extended our work to the problems of security, privacy and service level agreement among partners. Recently, we started a study on service composition for software architects where services are coming from different providers with different plans (capacity, degree of resilience...). The objective is to support the architects to select the most accurate services (wrt. to their requirements, both functional and non-functional) and plans for building their software. We also compute the properties that we enforce for the composition of these services.