Research Of Time Modling And Its Consistency Verification In Workflow System

Time management is an important part of workflow management system.The more complicated the enterprise application is,the more powerful the time management technology should be.Effective modeling of time information in workflow systems is one of the current research hotspots due to the complexity of expressing and analyzing time notion and the lack of uniform specification and standard of time modeling.The research on time modeling and time management is significant to enrich the theory of workflow modeling,to ensure the efficient execution of workflow plans and to actualize the complicated enterprise application effectively.Workflow pattern theory doesn't make much progress after its foundation.A few modeling methods use workflow pattern as an important design principle consciously. YAWL workflow language wholly supports classical workflow patterns but it's weak in workflow time management.In addition,traditional workflow systems are doubtful due to the lack of flexibility.Research based on the problems described above are as follows.Firstly,workflow patterns and the time information contained in them have been deeply researched based on the analysis of time constraints and one kind of time modeling method combining interval time expression and point time expression has been proposed which have then been employed in the process of time modeling of the classical workflow patternsSecondly,the setting up of workflow temporal constraint networks and its consistency verification have been deeply researched in this paper.First,the definition of WTCN(Workflow Temporal Constraint Networks) and its related calculations are given considering the expression of workflow temporal constraints and its transformation.Second,one kind of WTCN setting up project has been given based on analyzing the temporal constraints of workflow patterns to detect the confliction in process by using the algorithm of verifying the consistency of workflow temporal constraints.Third,the project above has been employed to YAWL workflow management system and the implement process and running effect are shown after that.In the end,one kind of dynamic and adaptive process modeling framework has been brought up on the notion of temporal constraints to deal with the processes that can't be predefined totally in the phase of process modeling and related validity and consistency problems of workflow temporal constraints in the course of revising the process definition.In this framework,instance customization is offered in an intuitive graphical language to meet specific requirements,where as analysis on the correctness and consistency of temporal constraints of the instance template is provided through workflow temporal constraints networks reasoning.