Study On A Time Management Model For Distributed Workflow Systems

At present,globalization becomes the trend of economy.In this new environment, the differences in time zone,time granularity and work time have become an important factor for business collaboration and distributed heterogeneous system integration.As business collaboration across organizations becomes more and more frequent,workflow management systems have to take these time difference factors into consideration so as to carry out the seamless collaboration and efficient cooperation of business processes under different time standard.Otherwise,it may cause a series of problems,such as:1) it may disorder the schedule of business process,result in frequent exception and error,and make tasks unable to reach the right person at the right time point;2) the difference of time standard and work time make the distributed heterogeneous system integration complex and difficult,and even run it aground;3) the lack of uniform time expression system makes it impossible to complete the verification of business processes.So the time differences must be considered both in the definition phase and in the enactment phase in workflow,as well as the surveillance management in order to support the global business collaboration and satisfy the time restrictions.Distributed Workflow Management System(DWfS) is one of the strong and useful tools to model and enact business collaboration processes as well as distributed and heterogeneous system integration applications.However,current researches on DWfS do not setup a holistic time management model to consider these time differences together.There are only some which concerns on a certain part,such as time zone difference and time granularity difference separatively.And there are seldom researches about the work time difference appears.Aiming at solving the above problems,this paper builds an integrated time management model,called DWfS-TMM(Distributed Workflow System-Time Management Model),for distributed workflow systems,which supports the distributed collaboration of business activities model and operation across different time zone,in multi-granularity of time and different work time.The main contents of the paper includes:1) build an integrated time expression system which is based on the distributed workflow system,and put forward the time transition rules among different time zones,multi-granularity of time and different work time,which is the combination of the analysis of time zone in and time granularity in;2) describe the static definition,the dynamic operation and the network structure of the workflow, and analyze the temporal constraints;3) study business processes optimization and dynamic adjustment algorithm based on DWfS-TMM,and realize the static build-time and the dynamic run-time of the model,as well as the temporal consistency checking and the optimization of the workflow network;4) It is shown from a case study that the presented DWfS-TMM model is useful and practicable.During the analysis of this case,XML Schema of the model is defined;the modeling of the business processes and the emulation optimization analysis of the model are completed.All these show that the model can solve the problems of the business collaboration and distributed heterogeneous system integration caused by these time differences.