Associative Composition of Web Service Invocation Sequences Based on Agent Interaction Diagrams

Building complex systems requires a systematic approach. One challenge of this is modeling behavior. To support this a kind of UML sequence diagram (AUML) is used in multi-agent systems. In Petri net-based, Agent- and Organization-Oriented Software Engineering (Paose), Petri nets are used to provide a formal semantics for an adapted version of AUML called Agent interaction protocol diagrams (Aips). Also using Petri nets, Fettke and Reisig address system composition based on Reisig's associative composition calculus for their HERAKLIT approach. By combining their results with Paose, systems can be built systematically based on Aips. They model web service interactions as reactions of a complex trigger of a system. Based on the Petri net semantics, they are aggregated within roles, which are then assigned to web services. With this rigorous approach, we can provide a "proof by construction" approach to model web service composition spanning distributed web services, limited to their control flow. The advantages and limitations of this type of modeling are discussed in detail.