Synthesizing Components with Sessions from Collaboration-Oriented Service Specifications

A fundamental problem in the area of service engineering is the so-called cross-cutting nature of services, i.e., that service behavior results from a collaboration of partial component behaviors. We present an approach for model-based service engineering, in which system component models are derived automatically from collaboration models. These are specifications of sub-services incorporating both the local behavior of the components and the necessary inter-component communication. The collaborations are expressed in a compact and self-contained way by UML collaborations and activities. The UML activities can express service compositions precisely, so that components may be derived automatically by means of a model transformation. In this paper, we focus on the important issue of how to coordinate and compose collaborations that are executed with several sessions at the same time. We introduce an extension to activities for session selection. Moreover, we explain how this composition is mapped onto the components and how it can be translated into executable code.