A flexible process model facilitated enactment

Control flow modeling in workflow systems commonly focuses on describing the semantics of routing relationship between activities. It constructs process routing structures by composing various kinds of split nodes and join nodes. But this approach isn´t appropriate for workflow engine to execute and results in the complication of realization of the workflow engine. To accord with the nature of control flow, we investigate the control and respondence relation between process and activities firstly, then the routing relationship between activities directly. A control flow modeling approach based on ECA rules is proposed, which can model the dynamic behaviors of workflow by allowing the process and activity respond the events sent from inside and outside the workflow system. Moreover, complicated routing semantics are modeled by links and control points. With this approach, the executing mechanism of control flow is unified. It simplifies the realization of workflow engine.