Formal or Not, but Precise Modelling of Services with CASL4SOA and SoaML

The emergence of service-oriented architecture (SOA) enables business functionalities to be invoked over a remote network, and thus requires specific modelling methods to develop service-oriented solutions. In this paper, we focus on precise service modelling and provide two approaches, one based on a standard widespread not formal notation (SoaML), and the other based on a formal notation (CASL4SOA). We chose SoaML introduced by OMG as a standard UML profile for modelling services, and CASL4SOA, a formal visual notation for service oriented systems based on CASL that resulted from a unification effort of the algebraic specification community. We illustrate both approaches using a case study.