This paper discusses a combinatorial problem about the selection of candidates for Web service compositions. The problem occurs if we assume that a discovery process has identified several candidates for each task of a composition and if the selection must consider multiple criteria. We anticipate to use quality-of-service (QoS) categories as selection criteria and thus the problem is about optimising the QoS of compositions at their planning-phase. This paper will explain this problem and propose different heuristics as possible solutions. Based on a software simulation a performance evaluation of these heuristics is given.
Michael C. Jaeger, Gregor Rojec-Goldmann