Workflow Service Extensions for UNICORE 6-Utilising a Standard WS-BPEL Engine for Grid Service Orchestration

The BIS-Grid project(1), a BMBF-funded project in the context of the German D-Grid initiative, focusses on realising Enterprise Application Integration using Grid technologies to proof that Grid technologies are feasible for information systems integration. Small and medium enterprises shall be enabled to integrate heterogeneous business information systems and to use external Grid resources and services with affordable effort. In this paper, we describe service extensions to UNICORE 6 to use an arbitrary WS-BPEL workflow engine and standard WS-BPEL to orchestrate stateful, WSRF-based Web Services, also called Grid Services. Thereby, we focus on how to combine the arbitrary workflow engine with UNICORE 6, and on how to access workflows and workflow instances. The workflows itself are also provided as Grid Services, realised by a Workflow Management Service that deploys Workflow Services within UNICORE 6, each wrapping a WS-BPEL workflow that is, deployed in the arbitrary workflow engine.