An automatic service composition algorithm for constructing the global optimal service tree based on QoS

As the non-functional semantics of Web service, Quality of Service (QoS) takes an essential role in actual use of Web services. It is necessary to take the QoS into account in the discovery and composition of Web services. This paper presents an automatic service composition algorithm to generate the composite services which are called service trees, and then addresses the issue of composite service selection by applying the Multiple Criteria Decision Making (MCDM) technique on the principle of globally optimize the QoS of composite services. A QoS ontology is established to describe and measure service quality, and a use case about the reservoir is given to show the automatic composition of the Geospatial Web Service (GWS).