Research On The System Of Product Data Management Based On Colored Timed Workflow Net

The function of product data management (PDM) system is to manage data and processes having correlations with product design. First of All, The general design of PDM system based on J2EE platform is completed. Specifically three-tier C/S architecture and system functions model are built, database design to develop PDM system is proposed. Then profound researches about the theories of workflow management of PDM system are completed. Since the workflow management not only has to manage relationships and data flow among activities, but also has to manage resources needing by activities, data access control, versions of design object generating with workflow, function models, namely, document management based on workflow, version management of product structure and documents, access control management, are discussed and theirs realized principles and applications are presented also.Concurrent workflow model based on colored timed Petri net is introduced into the workflow management system, and floating-delay is adopted to define colored timed Petri net. Transformation from workflow model to colored timed workflow net model is realized through workflow engine. Then the methods using reachability graph to analyze static and dynamic structural performance of colored timed workflow net are improved, and the theorem verifying whether there are deadlocks or traps in concurrent workflow are put forward using reachability graph. According to the trigger rules of colored timed workflow net, simulation strategy is build to describe the action of workflow system. Furthermore, intervals between each task are minimum and avoiding tasks overflow are taken as optimal objective of tasks scheduling. In that case tasks scheduling of workflow management system in time level is implemented. Mathematic models of multitasks scheduling about basic colored timed workflow net are deduced, and the formulae of calculating the whole workflows running time are presented. In the course of explanation, a concurrent examine and approve workflow model having or-splits jumping out function is taken as an example to analyze and validate the presented approaches.Based on workflow model and its realization, the theories of document...