PlanICS - a Web Service Composition Toolset

The paper presents a prototype toolset to planning by automatic composition of web services. The main idea consists in arranging the composition into two main phases: abstract and concrete one, as well as to handle fully declarative user queries. The first abstract stage aims at finding all the possible sequences of the types of the services that can potentially satisfy the user request. The result, referred to as an abstract plan, is used in the concrete planning phase, which substitutes the types of the services with their concrete instances registered in the system. This is obtained by translating the problem of finding a composition of concrete services satisfying the user query into the reachability problem for (timed) automata with discrete data and parametric assignments, taking into account the concrete instances of services as well as the user query. Next, SAT-based parametric bounded model checking is used to obtaining the solutions in form of sequences of services invocations together with the example services' input values.