Workflow Patterns Website (http://www.workflowpatterns.com/)
The Workflow Patterns initiative in started in 1999. The aim of this initiative is to provide a conceptual basis for process technology. In particular, the research provides a thorough examination of the various perspectives (control flow, data, resource, and exception handling) that need to be supported by a workflow language or a business process modeling language. The results can be used for examining the suitability of a particular process language or workflow system for a particular project, assessing relative strengths and weaknesses of various approaches to process specification, implementing certain business requirements in a particular process-aware information system, and as a basis for language and tool development.
On the web site http://www.workflowpatterns.com/ you will find detailed descriptions of patterns for the various perspectives relevant for process-aware information systems: control-flow, data, resource, and exception handling. In addition you will find detailed evaluations of various process languages, (proposed) standards for web service compositions, and workflow systems in terms of this patterns.