Guiding Service Composition in a Visual Service Creation Environment

Current day service composition languages like WS-BPEL require in-depth knowledge of this language by the service composition designers. In this paper we present a high-level, visual Service Creation Environment (SCE). This SCE provides service composition templates, verifica-tion of compatibility and guidelines, and advanced separa-tion of concerns through Aspect-Oriented Software Devel-opment. Composition templates are abstract descriptions of reusable compositions containing several placeholders for services. Services are verified to be compatible with the composition template when a service is mapped onto a composition template’s placeholder. Composition guide-lines such as QoS constraints can be added to the SCE and verified. The modularization of crosscutting concerns is supported by the SCE through the general-purpose Padus Aspect-Oriented Programming language and the possibil-ity to add concern-specific languages on top of Padus. The SCE generates the appropriate WS-BPEL processes given a complete and verified service composition. 1

Constructing Web Services out of Generic Component Compositions

Todays information systems are built using various component models such as Enterprise Java Beans, JavaBeans, Microsoft COM+, and CORBA distributed objects. In this paper we argue that it is crucial for designers of information systems to interactively build and test systems constructed from (a) components (enabling interoperability across component models) and (b) Web services at the same time