Steffen Higel, Dave Lewis, Vincent Wade

Dynamic Web-Service Composition: eBusiness Just For You!

Knowledge and Data Engineering Group
Department of Computer Science
Trinity College Dublin

As businesses increasingly strive to offer 'service portals' on the web, their business processes are being encapsulated within web-services or offered via web services. Initially, this has been particularly focused in the business to customer area, for example on-line brokerage services, information search services, online travel agents and so forth. However, in recent years the takeup of web services to support the business to business market has also increased through their appearance across the value chain of telecoms providers[Lofthouse04] and the emergence of value added service providers (such as content providers and retailers). In supporting these B2B and B2C business processes, a variety of technologies such as workflow automation, scripting languages or individual applications supported via application service providers have been employed. Market forces as well as operating constraints can cause the need for dynamic changes to both the business models and services that an organisation offers. However all of the technical solutions listed earlier suffer from a lack of dynamic adaptability. Such solutions incur considerable effort in process re-engineering and customisation. More lightweight solutions to service composition are now being sought to allow organisations greater flexibility and more rapid process adaptivity. Various industry and standards bodies have reacted by attempting to specify greater flexibility in Web Service composition and integration. For example, W3C as part of its Web Service Activity has sought to define requirements and techniques to support dynamic service choreography; OASIS is standardising a scripting approach for Web Services called Business Process Execution Language for Web Services. This paper explores an approach to near run-time service composition for customising web-service behaviour dynamically, with a focus on the reuse of existing compositions.