Non-redundant web services composition based on a two-phase algorithm

Recently, there has been growing interest in developing web services composition search systems. Current solutions have the drawback of including redundant web services in the results. In this paper, we proposed a non-redundant web services composition search system called NRC, which is based on a two-phase algorithm. In the NRC system, the Link Index is built over web services according to their connectivity. In the forward phase, the candidate compositions are efficiently found by searching the Link Index. In the backward phase, the candidate compositions decomposed into several non-redundant web services compositions by using the concept of tokens. Results of experiments involving data sets with different characteristics show the performance benefits of the NRC techniques in comparison to state-of-the-art composition approaches.