Research And Application Of Transactional Workflow Model Based On Colored Petri Net

Workflow technology is a core technology that assists enterprise business processes to realize modeling, simulation, analysis, optimization management. The workflow management technique separates the process logic from the applications, and achieves the purpose of process modeling, recompose and reuse. With the development of workflow, more and more researchers are concerned with the reliability and correctness of WfMS. A transaction supporting workflow can apply transactions that originally proposed in the context of databases to the context of workflow to deal with error recovery and concurrency control, thus guaranteeing the consistency and correctness of the operation results. At present, the workflow system does not support transactions or cannot support transactions sufficiently. The correctness and reliability of the system is the key to success. A lack of transaction supporting obstructs the widespread application of the WfMS.In this paper, we analyze the differences between the transaction in WfMS, the traditional transaction, and the advanced transaction. Based on the analysis, we discuss the failure types and failure handling policies of WFMS. With the conclusion, a transactional workflow model based on Petri net was proposed. To make the workflow management system to be more reliable and robust, in the model, we add the level of transactional processing to activity and define transaction sphere to the model. From the application point of view, we expanded the transaction sphere. In the transaction sphere we provide the rules for transaction recovery to guarantee the workflow process be correct and consistent. The model will enable the user to add task state dependency before the workflow operation. The user can express both the transaction-oriented and application-oriented requirements of complex business rules through the task state dependency. The model is expected to provide a theoretically sound basis for current workflow systems to expand their transactional workflow supports.We discuss the design and implementation of the transaction expression in Process Definition Subsystem and Enactment Service Subsystem of Flex Work, which is a workflow management system with support of transaction. We expect that our work will benefit the research and application of Transactional Workflow Management System.