Graphical Workflow Modeling And Correctness Verification Methods

Workflow Management System, a kind of computer software system, supports and monitors the implementation of business process, however, practical experience indicates that the definition of real-world workflow application is a complex and error-prone process. Workflow lacks the solid theoretical foundation, many models are based on intuitive understanding without strict restraint. The verification issues lack mature theory, and different workflow systems exist so many differences that there is short of unified verification methods applied in all types of workflow models. Therefore, improving the model design and verifying the correctness of the process have become the important research directions.Firstly, this thesis summarizes the development of the workflow system and introduces the interrelated concepts, analyzes the advantages and disadvantages of workflow models based on activity diagram, formal language, petri-net and so on, provides the design principles and elements of working model, refers XML process definition language and on this basis designs Extend XML process definition language which has more expressed capacity on organization model and flexible support of workflow.Secondly, grammar verification, structural verification and semantic verification ensure the correctness of workflow process. Grammar verification includes seven standards, structural verification provides an effective algorithm to gradually reduce graph through a set of reduction rules, semantic verification introduces the concept of data semantic and design an effective approach with time constraint.Finally, designing and realizing a workflow modelling tool based on EXPDL, and introduce the functions, the architecture and the implementation technique of this system.