Deriving business processes with service level agreements from early requirements

When designing a service-based business process employing loosely coupled services, one is not only interested in guaranteeing a certain flow of work, but also in how the work will be performed. This involves the consideration of non-functional properties which go from execution time and costs, to trust and security. Ideally, a designer would like to have guarantees over the behavior of the services involved in the process. These guarantees are the object of Service Level Agreements. We propose a methodology to design service-based business processes together with Service Level Agreements that guarantee a certain quality of execution, with particular emphasis on security. Starting from an early requirements analysis modeled in the Secure Tropos formalism, we provide a set of user-guided transformations and reasoning tools the final output of which is a set of processes in the form of Secure BPELs together with a set of Service Level Agreements to be signed by participating services. To show the potential impact of the approach, we illustrate the functioning of the methodology on a collaborative procurement scenario derived from the application domain of a research project.