Graphical Composition of Grid Services

Grid services and web services have similarities but also significant differences. Although conceived for web services, it is seen how BPEL (Business Process Execution Logic) can be used to orchestrate a collection of grid services. It is explained how CRESS (Chisel Representation Employing Systematic Specification) has been extended to describe grid service composition. The CRESS descriptions are automatically converted into BPEL/WSDL code for practical realisation of the composed services. This achieves orchestration of grid services deployed using the widely used Globus Toolkit and ActiveBPEL interpreter. The same CRESS descriptions are automatically translated into LOTOS, allowing systematic checks for interoperability and logical errors prior to implementation