Propagation Service Decision Method for Web Services Composition in u-Lifecare System

In Web environment, multiple Web service(WS)s may provide similar functionalities with different nonfunctional property values (e.g. different QoS metrics). Quality of service (QoS) metrics of WSs are critical factors to select appropriate WSs execution path in WSs composition as it requires expensive computation cost to find out appropriate execution path in Web environment, i.e O(MN) assuming that there will be M candidate services and N WSs in composition model. Thus, it is very important to decide which service execution path will be more suitable to users in execution time. Existing methods find execution path in design time which is inefficient as the QoS metrics of WSs are changed frequently in real time. Thus, in this paper, we propose a dynamic service execution path selection method called PSDM (propagation service decision method) in execution time for web service composition in u-Lifecare system. The proposed scheme is analyzed and experiment results are shown in terms of frequency of service execution path.