A Heterogeneous Approach to Service-Oriented Systems Specification: Two Months Later

Service-oriented architecture (SOA) is a relatively new ap- proach to software system development. It divides system functionality to independent, loosely coupled, interoperable services. In this paper we propose a new heterogeneous specification approach of SOA systems where a heterogeneous structured specification consists of a number of specifications of individual services written in a "local" logic and where the specification of their interactions is separately described in a "global" logic. A main feature of our global logic is the possibility of describing the dynamic change of service communications over time. Our approach is based on the theory of institutions: we show that both logics form institutions and that these institutions are connected by an institution comorphism. We illustrate our approach by a simple scenario of an e- university management system and show the power of the heterogeneous specification approach by a compositional refinement of the scenario.