A Three-Layer Model for Business Processes --- Process Logic, Case Semantics and Workflow Management

Workflow management aims at the controlling, monitoring,optimizing and supporting of business processes. Well designed formalmodels will facilitate such management since they provide explicitrepresentations of business processes as the basis for computerizedanalysis, verification and execution. Petri Nets have been recognizedas the most suitable candidate for workflow modeling, and as such,formal models based on Petri Nets have been proposed, among them WF-netby Aalst is the most popular one. But WF-net has turned out to beconceptually chaotic as will be illustrated in this paper with anexample from Aalst's book. This paper proposes a series of models forthe description and analysis of business processes at conceptuallydifferent hierarchical layers. Analytic goals and methods at theselayers are also discussed. The underlying structure, shared by allthese models, is SYNCHRONIZER, which is designed with the guidance ofsynchrony theory of GNT (General Net Theory) and serves as theconceptual foundation of workflow formal models. Structurally,synchronizers connect tasks to form a whole while dynamicallysynchronizers control tasks to achieve synchronization.