Models for trustworthy service and process oriented systems

Service and process-oriented systems promise to provide more effective business and work processes and more flexible and adaptable enterprise IT systems. However, the technologies and standards are still young and unstable, making research in their theoretical foundations increasingly important. Our studies focus on two dichotomies: The global/local views of service interactions, and their imperative/declarative specification. A global view of service interactions describes a process as a protocol for interactions, as e.g. an UML sequence diagram or a WS-CDL choreography. A local view describes the system as a set of processes, e.g. specified as a π-calculus or WS-BPEL process, implementing each participant in the process. While the global view is what is usually provided as specification, the local view is a necessary step towards a distributed implementation. If processes are defined imperatively, the control flow is defined explicitly, e.g. as a sequence or flow graph of interactions/commands. In a declarative approach processes are described as a collection of conditions they should fulfill in order to be considered correct. The two approaches have evolved rather independently from each other. Our thesis is that we can provide a theoretical framework based on typed concurrent process and concurrent constraint calculi for the specification, analysis and verification of service and process oriented system designs which bridges the global and local view and combines the imperative and declarative specification approaches, and can be employed to increase the trust in the developed systems. This article describes our main motivations, results and future research directions.