Rules in the Semantic Web Services Language (SWSL): An Overview for Standardization Directions

We give an overview of rules in the Semantic Web Services Language (SWSL) from the viewpoint of directions for standardization. This includes requirements, tasks about services, kinds of knowledge, combining rules with ontologies, suitability of fundamental knowledge representations and desirability of particular expressive features. Note: To Find More about this paper For updated/extended versions of this paper, and additional related material, see http://ebusiness.mit.edu/bgrosof/#SWSLPosnPapForW3RuleWksh starting in earlyor mid-April 2005. 1. Intro to Semantic Web Services Language (SWSL) The promise of Web services and the need for widely accepted standards enabling them are widely recognized, and considerable efforts are underway to define and evolve such standards in the commercial realm. Prominent among these are: Oasis’s UDDI, BPEL4WS, and Web Services Security; and W3C’s WSDL and Choreography Description Language. At the same time, recognition is growing of the need for richer semantic specifications of Web services, based on a comprehensive representational framework that spans the full range of service-related concepts. Because an expressive representation framework permits the specification of many different aspects of services, it can provide a foundation for a broad range of activities, across the Web service lifecycle, while enabling radically more and cheaper reuse of such specification knowledge across those aspects, across applications and organizations, and over the duration of the lifecycle. It can support cheaper, broader, and deeper automation of many service tasks, including: service selection and invocation; translation of message content between heterogeneous interoperating services; service moni-