Multiple non-functional criteria service selection based on user preferences and decision strategies

In order to choose from a list of functionally similar services, users often need to make their decisions based on multiple non-functional criteria they require on the target service. It is a natural fit to apply the Multi-Criteria Decision Making (MCDM) theory to this selection problem. However, the high demand of MCDM approaches on user expertise and user involvement could become an obstacle of using them for service selection. In this paper, we address this issue by taking a user-centric standpoint to design the non-functional criteria based service selection system. On one hand, we try to reduce the workload and the skill level requirement on users. On the other hand, we still give them the flexibility to define the necessary information, which include their preferences on multiple criteria, as well as the decision strategies they would follow to select the desired services from a list of alternatives. The former is crucial for optimal decision making. The latter is often ignored by most of the service selection systems and a common default selection strategy is to find a service which has the best overall score calculated by a certain formula. In reality, users may not necessarily follow this strategy and there are many other possible strategies they may follow. We should take this into consideration when designing selection systems. We use a case study to show that our system could produce a more accurate and customized result for individual users.