YAWL (Yet Another Workflow Language), an open source workflow
language/management system, is based on a rigorous analysis of
existing workflow management systems and workflow languages. Unlike
traditional systems it provides direct support for all of the workflow
patterns (http://www.workflowpatterns.com). YAWL supports the control-
flow perspective, the data perspective, and is able to interact with
web services declared in WSDL. It is based on a distributed, web-
friendly infrastructure