An Research On The Expressiveness And Relevant Comparative Analysis Of The UML-based Workflow Modeling Language

At present, the application information technology in enterprise has changed from systems that aid people to finish some function of the enterprise to the systems which core is business process. It has been an urgent need to seeking one that can support the running of enterprise from the view of business process in order to improve the efficiency of the work, to optimize the process, or to improve the management level. At the same time, the new patterns such as parallel engineer, agile manufacture, virtual manufacture etc. need the information system platform that can support the business process. So, as a information technology to automate the business process and to support the process management, the workflow technology has been paid much attention because of the difference from the traditional information system. When more and more enterprise seek to improve their comparability by effective information technology, workflow system would have more advantage. Workflow technique uses the workflow management system as its base platform to automate the business process and to support process optimization. Workflow management system provides difference function at the build stage and the run time stage. At build time stage, people can use some modeling technique to build the logic model of the business process called workflow model. A workflow model indicate what activity a business process should do and the task of the activity, and also the department and worker who responsible for the activity, it also point out in what condition a post activity can start. At running stage, workflow management system provides control function and inactive function. The control function of run time stage is used for building workflow instance according to the workflow model and to manage the running of those instances. A workflow instance is a time of running of the business process, also is one time the business be processed. When workflow management system builds a instance of a workflow model, it would assign the activity and task between the organize and the workers according to the model, the business data also is transferred at the same time. An other important responsibility for workflow management system is schedule the post activity when some activity finished or some condition is satisfied. The interactive function at run time stage provides a interface for the participator to interact with the workflow instance. By this function, the participator can know what they should do; they can also receive and submit the data by this interface. All the things are done according to the workflow model. So, the workflow model is very important and as a result, the modeling technique is important, too. The typical modeling technique which are in using at present include the activity network modeling technique proposed by IBM,the event-driven process chain modeling technique and the coordination-based modeling technique. Those techniques are proposed form different view; the elements and the semantic are also different. So, the model generated by a technique of one workflow management system can't be used in other system. When the enterprise need the information system stronger and more easy to use, these modeling technique can't accommodate new need. They aren't formalization and their expressiveness also isn't enough. So, to construct more powerful modeling technique is urgent. The Petri-net based modeling technique has gained much attention of the researchers. Although it isn't orient from the workflow area, but it is used for modeling the dynamic system and has a graphic interface, so, it is introduced into workflow modeling. An main important reason of doing this is that Petri-net modeling a system by the status, and it is formalization. So, if Petri-net can be used as workflow modeling technique, the model checking and simulation can be done automated and status-based modeling technique would have stronger expressiveness. But there are some problems. A workflow system consists of the workflow management system and workflow instances running in it. Workflow model indicate how the workflow system behave and it has the specify behavior mechanism. The Petri-net originally is used for modeling the physics system that has fixed structure and is closed and active, so it wouldn't be fitful to model the mechanism of workflow system. So, if Petri-net is used directly in workflow modeling area, there would be so some difficulty and wouldn't satisfy the expressiveness for modeling. In the other hand, as a standard, the UML modeling language (Unified Modeling Language) is proposed for software development and it is general. The activity diagram include in UML is used for expressing the dynamic behavior of a system. UML language is a public standard, so, if it can be using for modeling, it would be good for solve the incompatibility between different workflow...