Management of compositions of e- and m-business Web services with multiple classes of service

The concept of a Web service, as defined by W3C (World Wide Web Consortium), represents a distributed component using XML messaging. Compositions of Web services are increasingly used to create new IT capabilities fast and flexibly, in an ad hoc manner. This work extends the W3C concept of a Web service in two ways. First, we enable a Web service to offer several variations of service and QoS. In other words, we add the concept of classes of service for Web services. This widens the usability of a particular Web service. Second, we explore dynamic (i.e., run-time) adaptation and management based on the manipulation of classes of service. Our dynamic adaptation mechanisms include switching, deactivation/reactivation, and creation of classes of service. Management and dynamic adaptation of Web service compositions further improve the overall flexibility and adaptability of IT systems using Web services.