Semi-automatic Web Service Composition Optimization with Global Constraint

For semi-automatic composite services, operators make the universal services composite model that adapts itself to application demands according to given business background. This paper present independent global constraints Web service composition optimization methods based on discrete particle swarm optimization (DPSO) and extended color Petri net (eCPN). Firstly, a eCPN modeling methods which can describe multi-attribute multi-constraint relations and associate relation between component services is proposed. Secondly, combining with the properties of icon, DPSOis used to search a legal firing sequence in the eCPN model, and the composite service corresponding to the legal firing sequence.Using legal firing sequences of the Petri net makes the service composition locating space based on DPSO shrink greatly. Theoretical analysis and experimental results indicate that this method owns both lower computation cost and higher success ratio of service composition.