Type-Aware Web Service Composition Using Boolean Satisfiability Solver

The goal of the Web Service Composition (WSC) problem is to find an optimal "composition" of web services to satisfy a given request using their syntactic and/or semantic features, when no single service satisfies it. In this paper, in particular, we study the WSC problem from semantic aspects, exploiting the supertype-subtype relationship among parameters, and propose a novel solutionbased on techniques for the boolean satisfiability problem (SAT). Given a set of web service descriptions and a requirement web service, we reduce the WSC problem into a reachability problem on a state-transition system, and then we find the shortest path for the reachability problem, which is amount to the optimal composition. A preliminary experiment using 7 examples reveals that our proposal can find optimal compositions of web services efficiently.