A visual language and environment for composing web services

Implementing complex web service-based systems requires tools to effectively describe and co-ordinate the composition of web service components. We have developed a new domain-specific visual language called ViTABaL-WS and built a prototype design tool to support modelling complex interactions between web service components. ViTABaL-WS uses a "Tool Abstraction" metaphor for describing relationships between service definitions, and multiple-views of data-flow, control-flow and event propagation in a modelled process. The tool supports the generation of Business Process Execution Language (BPEL) definitions from a model, directly deploys a generated model to a workflow engine, and supports dynamic visualisation of a running BPEL process. Copyright 2005 ACM.