Dynamic workflow model fragmentation for distributed execution

Workflow fragments are partitions of workflow model, and workflow model fragmentation is to partition a workflow model into fragments, which can be manipulated by multiple workflow servers. In this paper a novel dynamic workflow model fragmentation algorithm is proposed. Based on the well-known Petri net formalism, this algorithm partitioned the centralized process model into fragments step by step while the process is executed. The fragments created can migrate to proper servers, where tasks are performed and new fragments are created and forwarded to other servers to be executed in succession. The advantages of the proposed dynamic model fragmentation method include the enhanced scalability by outsourcing the business functionalities, the increased flexibility by designating execution sites on-the-fly, the avoidance of redundant information transfer by judging their pre-conditions before forwarding fragments, etc. An industrial case is given to validate the proposed approach. Later some discussions are made on the correctness of the algorithm and the structural properties of the workflow model. Finally the future research perspectives are pointed out.