NFP-aware Semantic Web Services Selection

The discovery of a semantic web service (SWS) is the act of locating a machine-processable description of a SWS-related resource that may have been previously unknown and that meets certain functional criteria. The increasing availability of services that offer similar functionalities requires the discovery process to be enhanced with a selection phase that considers non-functional properties (NFPs) of services. This paper proposes a model to describe these properties and a novel approach to service selection. Our approach is based on the design of matching rules by means of mediators defined by sets of rules stating the condition for successful matches. These rules are based on the ontological description of objects representing NFPs that are required and offered. In particular, we define a set of rule schemas to support mediation and matching for a class of user-defined NFP-constraints clustered according to specified constraint operators. Rules support matching for both qualitative and quantitative non-functional properties.