BAs supported by automated analysis can identify potentially costly mistakes early in the process life-cycle, according to ter Hofstede, and they can rest assured their models have an unambiguous meaning as YAWL is rigorously defined.

"There should be no surprises during execution," he said. "Nor should there be a need to have lengthy debates about the meaning of the concepts used!"

YAWL now consists of an open source engine and GUI editor, both written in Java and released under the LGPL. YAWL uses XML Schema, XPath, XQuery and XForms natively, and is compatible with SOAP and WSDL. Development is done in conjunction with the Eindhoven University of Technology in The Netherlands.

Another motivation behind YAWL was to make BPM vendors 'lift their game' and to increase opportunities for the more widespread use of BPM solutions.

"YAWL's open source model in addition provides a compelling argument for small to medium enterprises to explore the benefits of business process execution," ter Hofstede said. "Process execution environments are frequently criticized for their static approach to changing a process definition at runtime. YAWL offers a unique solution to dynamic workflow, widening the application of BPM technology into businesses with processes evolving so rapidly that they are literally changing as they are being executed."