The Research And Design Of The Workflow System Based On Petri Net

In recent years, along with the development of IT, especially the network communication technology, multi-media technology and database technology, the electronic document circulation of enterprise have been offered more wide developed space. Coming down to some aspects, such as how to handle document information, how to manage and organize the information with writing character as major content, especially how to control the dynamic transmission of these informations, the technology of workflow will be applied.The modeling methodology based on Petri net is a kind of modeling tool that integrate graphics and mathematics. It have been applied extensively in system modeling, analysis and control of many fields, such as communication protocol verification, network performance analysis, parallel programming design, knowledge ratiocination and artificial neural network etc. It is a good formalized modeling tool.This paper discusses the system structure and typical models of workflow management system, analyses the modeling method and the modeling technology based on Petri net. Based on workflow net, the mapping from Petri net to workflow is discussed. We improve the tranditional Petri net and combine the data stream and the controlling stream. It can operational control the external events and handle the complex model of nested structure.Paper is background with the processing system of official business of information flow. It focuses on how to apply the technology of Petri net in modeling of official workflow system. We made thoroughly researches and improvement on the control flow, information flow, systematic architecture, transitional firing and the response to external events. And designed a document circulation system based on Petri net.We achieved the works following:(1) This paper discussed the architecture of workflow management system and typical model, analysed various modeling methods of workflow entity. Thedescription and research on the parallel , asynchronous , distributed and stochastic system are offered powerful means by using Petri net to make mold.(2) Based on the workflow net, it discussed the mapping from Petri net to workflow. The arithmetic and transition firing of tranditional Petri net is improved. The data flow and the control flow are combined. It can carry out operational control for external events and handle the complex model of nest structure. 3 subclasses are added to analyse the rationality of the improvement.(3) According to the application demand and the example of official document circulation, set up the structure of official document cirulation by using improving Petri net. We proposed the arithmetic and design by using the platform of Lotus Domino/Notes.(4) We compiled some process by LotusScript. And give some for several problems, such as the automatic reversion dynamic track and the integrality of data.In the aim of the design, the official document circulation and administration of user and system is designed. The stability and reliability is ensured. Workflow is a systematic project; it is the crucial field in official automatization. So the study of the application of Petri net in workflow system has much meaning in theory and practice.