A Systematic Approach to Flexible Specification, Composition, and Restructuring

We introduce the ActivityFlow specification language for flexible specification, composition, and coordination of workflow activities. The most interesting features of the ActivityFlow specification language include: (1) a collection of specification mechanisms, allowing workflow designers to use a uniform workflow specification interface to describe different types (i.e., ad-hoc, administrative, or production) of workflows involved in their organizational processes– this feature helps to increase the flexibility of workflow processes in accommodating various types of changes; (2) a set of activity modeling facilities, enabling workflow designers to describe the flow of work declaratively and incrementally, allowing to reason about correct-ness and security of complex workflow activities independently from their underlying imple-mentation mechanisms; (3) an open architecture that supports user interaction as well as collaboration of workflow systems of different organizations, and a set of workflow activity restructuring operators to respond to dynamic changes of workflow activities. We end the paper with a series of simulation-based experiments that demonstrate the effectiveness of these restructuring operators and the implementation architecture of the ActivityFlow system