Workflow Process Engine Interface External Workflow Engines

We introduce the ActivityFlow speciication language for in-cremental speciication and exible coordination of workkow activities. The most interesting features of the ActivityFlow speciication language include (1) a collection of speciication mechanisms, which provides a workkow designer with a uniform workkow speciication interface to describe diierent types (i.e., ad-hoc, administrative, or production) of workkows involved in their organizational processes, and helps to increase the exibility of workkow processes in accommodating changes; (2) a set of activity modeling facilities, which enables the workkow designer to describe the ow of work declaratively and incrementally, allowing reasoning about correctness and security of complex workkow activities independently from their underlying implementation mechanisms; (3) an open architecture that supports user interaction as well as collaboration of workkow systems of diierent organizations.