Automated Composition of Web Services by Planning at the Knowledge Level

In this paper, we address the problem of the automated composition of web services by planning on their ``knowledge level`` models. We start from descriptions of web services in standard process modeling and execution languages, like BPEL4WS, and automatically translate them into a planning domain that models the interactions among services at the knowledge level. This allows us to avoid the explosion of the search space due to the usually large and possibly infinite ranges of data values that are exchanged among services, and thus to scale up the applicability of state-of-the-art techniques for the automated composition of web services. We present the theoretical framework, implement it, and provide an experimental evaluation that shows the practical advantage of our approach w.r.t. techniques that are not based on a knowledge-level representatio