Abstract
Due to the openness and dynamic characteristics of the network environment, the failure of component services in a composite Web service (CWS) can occur. CWS is a conglomeration of existing Web services (WSs) interacting together to offer a new value-added service. Hence, it is necessary to perform some transactions to ensure its correct and reliable execution. However, their introduction complicates its quality of service (QoS) analysis. How to analyze and evaluate its QoS values based on them becomes an important research issue. To address the problem, this paper introduces transactional properties of a single WS and CWS and conducts the performance analysis of basic workflow patterns such as sequential, parallel, selectable, and loop ones. Then, it develops an algorithm to compute the execution time of CWS and shows an example to illustrate the effectiveness of the proposed algorithm.