The Evaluation Of Alternative Process Plans In The Process Digitalization System

This subject is aimed at developing the evaluation subsystem of process plan in the Process Digitalization System. This system is carried on the technology economic assessment of process plan at the early stage of process scheme.The process plan is the technology foundation of part machining, and takes guidance for the part manufacture, and decides the productivity and the manufacturing cost of the part. In the view of machine manufacture, drawing up the process route and process method of part is not solely, and the different technological design principles can lead to different process plan. The person-machine-tool-part systems that these process plans specifies can all guarantee the part quality, but the different process plan can make different benefit, consume different labor, and attain different outcome. With the intensive market competition, the evaluation of alternative process plan has become one of primary mission of technology decision.This paper uses time and cost as the assessment index to make quantity appraise of the process plan. In the course of calculating process plan working time, it uses different methods to calculate process time in large quantities production or small scale production being counted with their characteristic. The method of estimating process time - " prototype working hours" is put forward, which is suitable for the process plan with a small amount of technology information. Its theory foundation and basic principle is also mentioned. As for the calculation of technology cost, this paper introduces the computational method which distinguishes with ordinary computational method of process cost - " unit time cost of machine ", this kind of method calculate the per hour machine cost, and according to the operation time calculate the operation cost. In carrying on the comprehensive evaluation, this paper uses the fuzzy evaluation method to convert theproductivity and the manufacturing cost which cannot be compared into theindexes which have identical dimension. And it makes the final evaluation to the process plan by this two indexes.This system is based on the elemental theories introduced by the upward, using Delphi programming language and Access database, and designs the friendly user interface, and realizes reasonably calling, and is accomplished the evaluation assignment of the process plan .The thesis is chiefly solved the technology and economic assessment question of process plan, and uses the database technique to realize information sharing and the seamless connection between this subsystem and Process Digitalization System. The article calculates the time and the cost of process plan, and selects the most excellent process plan among many process plans, not only makes and provides the reliable guaranty for lower level - manufacture, but also provides the information feedback for upper level - the process design, makes some contribution to the Process Management Digitalization.