Efficient Discovery of Collision-Free Service Combinations

Majority of service discovery research considers only primitive services as a suitable match for a given query while service combinations are not allowed. However, many realistic queries cannot be matched by individual services and only a combination of several services can satisfy such queries. Allowing service combinations or proper compositions of primitive services as a valid match introduces problems such as unwanted side-effects (i.e., producing an effect that is not requested), effect duplicities (i.e., producing some effect more than once) and contradictory effects (i.e., producing both an effect and its negation). Also the ranking of matched services has to be reconsidered for service combinations. In this paper, we address all the mentioned issues and present a matchmaking algorithm for retrieval of the best top k collision-free service combinations satisfying a given query.