Adaptable Discovery and Ranking of Context-Dependent Services

This paper emphasizes the role of contextual information and legal rules in publishing services, formulating contracts, discovering services, and their impact on ranking and adaptability. We use Configured Service concept, which is a package that bundles together service functionality, service contract, and service provision context. Service providers only publish Configured Services in a service registry. Service requesters query the registry to discover available services that can match their requirements. Often there is a semantic gap between the service query and the services in the registry. To deal with this, we discuss three query types. The discovery processes, employing different matching processes that are appropriate for the query types, will rank the services in order to enable the requester choose the most relevant service(s). Ranking is also essential when the number of matching´s is large. We identify the different situations that call for rediscovery and re-ranking of service queries. We include a brief account of formalism, within which all these activities are precisely described.