Research On Methodology For Mechanical Product Design Process Modeling, Evaluation And Optimization

The increase in product types and the constant improvement of product structure complexity make product design process lengthy and complicated. How to improve product design process efficiently, shorten product design time with assurance of product quality, implement efficient application and management of product design resource and improve product design efficiency is the key of enhancing enterprise competitiveness. The technologies of process improvement and process management are studied in this thesis. The contributions are as follows:Firstly, process model supporting product design process reengineering and corresponding reengineering method were researched. Based on the study of design structure matrix, a process model with structure of design structure matrix family was presented. In this model, product design process was decomposed by task level, part and component level, parameter level, and the information dependence relationships among activities of each level were described. The proposed model supports further decomposition in process better and combines the information of product design process model and product structure model. Strategy of process reengineering using this model was studied based on iteration analysis.Secondly, considering the problem of lacking efficient evaluation mechanism in process improvement research, a process evaluation method based on process simulation was presented. For better support of iterations and logical constants among activities, a child model of logical iteration structure tree was proposed based on the current research of process simulation method. In this model, topological relationships among activities were represented by tree structure. Process simulation model supporting complex process description was established combining design structure matrix family model and logical iteration structure tree model, corresponding simulation algorithm and simulation based process evaluation method were presented.Thirdly, based on the research of process reengineering and process simulation evaluation method, a framework of process improvement system supporting continuous process improvement was presented, and strategies of process improvement and improvement control were studied. Multi-cycle improvement mode was adopted to analysis, adjust and control the process improvement, then the controllability and effectiveness of improvement were enhanced.Fourthly, considering the problem of the immaturity in research and application of intelligent resource service, an intelligent resource service application and support method in product design process was researched in collaborative design environment. With intelligent resource service unit and design entities as objects of research, mechanism of intelligent resource service requirement promulgation and acquirement in design process management system was studied, framework of design process management system supporting intelligent resource service application was established. The proposed system supports requirement description, customization and application for professional intelligent resource in enterprise product design process, and is conducive to improve design efficiency and upgrade technical level. Finally, based on previous research, framework of product design process support system supporting process improvement and management was proposed. Generalized model of product design process was established integrating process evolution information structure and process topological structure. Information in the whole evolution period of design process can be described in the model. Then framework of product design process support system was established based on the generalized model. The proposed system can support and management the whole lifecycle of product design process from earlier process improvement and optimization to later process management and resource using.