Study On Multi-level Dynamic Robust Scheduling Method Under Virtual Manufacturing Cell Environment

In recent years, with the rapid development of China’s economic and the progress in technology, the market competition becomes increasingly fierce and the users’ demands tend to be diversified, which make the production made of small batch become the mainstream production made in production manufacturing. In order to adept to the diverse, dynamic and complex market environment, it needs higher demands to manufacturing companies.Therefore, it adopt advanced manufacturing technology and effective management mechanism, shorten the production cycle, improve the efficiency of traditional production,flexibility and competitiveness, which all has become an hot issue to study. Virtual cellular manufacturing systems as the development in cellular manufacturing system, has gradually become the advanced production mode which arose people’s attentions. Virtual cellular manufacturing can effectively reduce in-process inventory and production costs, and the cost of mobile devices and adjustment time. Therefore, it can improve the agility and production flexibility of the company; while greatly enhance the company’s efficiency in the use of resources.Virtual cell essentially is a production planning and control system, which required to allocate production task and production resource within the cell and between cells, dispel the conflict of resource demands within the cell and between cells, monitoring the implementation of production tasks. However, due to the complexities, dynamics and fitness of resources, it may happens uncertain disturbance and resource conflict, which will make the production plan can’t be implemented regularly, the delay of task, low efficiency of production system. In actual production, the efficiency and stability of production system will show certain conflict, and when appearing dynamic disturbance, Repeated Rescheduling would disrupt production implementation. Therefore, during the production process, we should consider the adjustment and changes which possibly brought by the actual workshop information and random events. When the production status change, we should take effective measures to conduct effective management and control and ensure the continuity and efficient in the production process.Through the research on virtual cell scheduling theory and the existing problems in the production dispatching process, on the premise of analyzing the random disturbance events,this article propose the multi-stage dynamic scheduling strategy on the basis of cycle drive and event drive; improve the flexibility of virtual manufacturing cell production scheduling.On the basis of analyzing event disturbance rate, aiming at the events with different influencing degrees, we will respectively take three solutions: Buffer integration strategy,local adjustment policies and rescheduling policies; in the research of rescheduling, it propose re-scheduling mechanism based on conflict resolution, based on different types of conflict, we take partly rescheduling or completely re-scheduling strategy. The partly rescheduling only needs to make adjustment on the production plan in the period of conflict time. It needn’t rescheduling the whole rescheduling period. On the conditions of without delays in duration, it improves the stability of production system. When seek the solution of whole rescheduling, we take the improved genetic algorithm to make rescheduling for all process in rescheduling period, for guarantying the completion time will not be delayed or minimized the delay. Under the premise to ensure system efficiency, we improve the of the production system and production process.To verify the effect of the multi-level, dynamic and robust strategy in the virtual cell which is proposed in the article, with the background of part of the parts processing in Hudong shipyard manufacturing plant, we apply the methods into the actual use, analyze and conclude the consequence, verify feasibility and effectiveness of the method.