A Petri Net Approach to Mediation-Aided Composition of Web Services

Recently, mediation-aided composition has been widely adopted when dealing with incompatibilities of services. However, existing approaches suffer from state space explosion in compatibility verification and cannot automatically generate the BPEL code. This paper presents a Petri net approach to mediation-aided composition of Web services. First, services are modeled as open WorkFlow Nets (oWFNs) and are composed using mediation transitions (MTs). Second, the modular reachability graph (MRG) of composition is automatically constructed and the compatibility is analyzed, so that the problem of state space explosion is significantly alleviated. Furthermore, an Event-Condition-Action (ECA) rule-based technique is developed to automatically generate the BPEL code of the composition, which can significantly save the time and labor of designers. Finally, the prototype system has been developed. Note to Practitioners-Web services are an emerging area for business process automation. This work presents a novel Petri net approach to mediation-aided composition of Web services. The proposed approach can greatly alleviate state space explosion to automatically verify the composition of partially incompatible services, and significantly save the time and labor of designers to obtain BPEL code. It consists of three phases: modeling composition of Web services, automatic verification of composition, and automatic generation of BPEL code. The prototype system has been developed based on the open source software PIPE and validated in a real-life case study. It is ready to be applied in industrial Web service composition for business automation.