Application Of Workflow Model Based-on Petri Net On Physical Distribution Management System

The concept of workflow comes from the domain of manufacture and office automation, to aim at the regular activity of routine. This concept brings to company much benefit, such as more efficiency, better flow control, improving service and suitability. According to architecture of workflow system raised by Workflow Management Coalition, a workflow management system contains modeling tools, workflow server, management tools and user interface. Workflow model is the basic part of system, different model correspond to different system. Currently, the method of workflow modeling include data flow diagram(DFD),IDEF,unified modeling language (UML) and Petri net. The front three's disadvantage is lacking abstract machine,lacking ability of dynamic analysis,lacking strict analytical procedure. Petri net have strict format, have ability of describing and analytical dynamic behavior, easy to imitate dynamic behavior of system. Entirely from the point of process, Petri net is a effective modeling tool for describe and analysis of complicated system. So, it fit to the modeling requirement of workflow domain.Raised by German scientist Carl Adam Petri at twenty century 60's, Petri net is a graphic mathematical modeling tool, used to describe and analyze information process system which have the characteristic of concurrency,asynchronism,parallelism,distribution.Petri net consists of two kinds of elements, one called place expressing state, the other called transition expressing change of state. The effect of place is to decide occur of transition. The effect of transition is to change state of place. Linked by a directional arc, the mutual dependent relationship of place and transition forms a Petri net. When use Petri net to describe a workflow model, the node of transition is used to describe mission, the node of place is used to describe ordinal relation of missions, the arc is used to describe the logic of activity. According to the basic architecture of workflow model, we introduce four basic structures to implement the Workflow-Petri net model. They are serialization% parallel,loop and select structure.Wrokflow-Petri net accurately differentiates the activity state of able and implement. If an abled state want to be implemented, there must exist a trigger, which can be explained as an external condition to let the abled state to be implemented. The trigger have four kind, called automatic trigger,artificial trigger time trigger and information trigger. This four kinds of trigger are used in definition of Wrokflow net, can let user intuitionisticly know every activity is how to be implement. Rationally using the four basic structures and triggers, we can get a high level Wrokflow model of definition and accuracy.This paper is based on a physical distribution management system, establish a Workflow-Petri net model. Paper analyze the actual process of physical distribution management system, summarize the activity of sale department,financial department and stock department, use these activities to component transitions, thereby accomplish a basic Workflow-Petri net model.The final of paper summarizes paper's research result, analyzes the lacking of the paper, indicates writer's further research direction and target.