Invited Speaker: Deciding Properties of Services

Summary form only given. Service orientation is a promising architectural concept to quickly and cost effectively compose encapsulated software components ("services"), and to adapt them to new requirements. Service orientation has evolved from very pragmatic problems and backgrounds. Central in the context of service-oriented computing is the notion of a partner service P for a given service, S. The service S communicates with P by means of asynchronous communication. The paper discusses the conceptual basis to formulate service orientation. It turns out that the behaviour of composted services can be represented in terms of (in general infinite) trees of reachable states and steps, with branching states denoting alternatives. Elementary operations on such trees suffice to characterize the above questions. Furthermore, "regular" infinite trees can be represented as finite graphs.