A Formal Model for Web Service Composition and Its Application Analysis

The formal description of Web service is the basis for analyzing and verifying the Web service composition. In this article, a simple pattern-oriented mathematical model for Web service composition is introduced according to fol- lowing steps: firstly, single service model is formally de- fined; secondly, several kinds of interaction logics between services are discussed and the composition pattern is pre- sented, the realization of the interaction logics are given at the same time; thirdly, the definition of Web service com- position model and the algorithms are presented; finally, a running example is discussed based on our model. The model can express the interactive logic relationships be- tween messages well and it can also be used to simulate the interaction between services via message passing1.