抄録
QoS-based Web service ranking problem is complex due to the diverse characteristic of QoS properties and the trade-off issue between them. A ranking mechanism needs to take into account different ways to effectively handle different types of QoS properties measured by different methods with different units and value types, as well as to unify those various QoS measurements in a fair comparison method. In this paper, we present a novel method for ranking and selecting Web services by introducing an extensible QoS model and a corresponding ranking algorithm. The QoS model takes into account the following considerations: different roles and preferences of users and system brokers in specifying QoS demand, different important levels between required QoS constraints and optional QoS preferences, and different QoS value comparison rules with respect to value types and comparative effects of QoS properties. AHP, a multiple criteria decision making method, is applied as an underlying mechanism for developing a flexible and effective ranking algorithm. The experimental results verify that our proposal produces significant achievement with our extensible QoS model and the new service ranking algorithm.
