Large And Complex Single Enterprise Virtual Cell Scheduling Problems Research Based On Blocking Flow Theory

With the steady decline in the production cycle, multi-species, small quantities of market demand,The changing production environment,Significantly improve the market’s individual needs,Companies need to adopt advanced production technology and production methods in order to remain invincible in the competition. Virtual cell manufacturing methods integrated concept of agile manufacturing and lean production will help improve manufacturing productivity, reduce production costs.Based on the research status of the virtual cell production, the paper considers the large and complex enterprise grade single piece of equipment more than one, use blocking flow theory represents distribution between the plant and the workpiece between the steps and the time constraints. The dispensing device and the workpiece and time constraints, building virtual unit blocking flow based scheduling model, will contain the reference scheduling problem into the maximum flow problem, using Dinic blocking flow algorithm in conjunction with the processing time to solve the matrix and the reduction of resource allocation and collection scheduling problem, in order to create the shortest cycle optimization goal, the establishment of integer programming model.Large, complex production process single species and spare parts logistics more complex product process, mutual restraint between the production processes, all production processes are related to the workpiece transport. And the cache processing unit is limited, except by the buffer capacity of the equipment processing capacity constraints, but also by the process path and the workpiece transport and other restrictions. Influencing factors and trends virtual unit scheduling station buffer capacity based on the workpiece processing stations buffer characterization, considering the workpiece transport section spacing requirements, velocity distribution, transportation routes network structure and other factors, analyzed the workpiece into the station bit buffer coupling between the station and leave the buffer area.Due to the uncertainty of the production process of the workpiece transport path, using blocking flow theory ideological tolerance capability of blocking dummy cell device to judge, conduct anti-blocking checked against data collected in the judge blocked. Finally, blocking digestion solution. The proposed method is applied to large and complex blocking digestion single enterprise, we analyze the situation and problems of the processing plant production. When the virtual unit schedules appear workpiece transport congestion, blocking the flow theory of efficient digestion, and set up mechanisms to ease digestion uncertainty during transport to ensure the effective production plans. By the results of analysis, degradation mechanisms may occur to some extent been avoided, to prove the effectiveness of the digestion avoid policy.To verify that the virtual cell production in large and complex application single enterprise manufacturing systems, the paper with the actual situation of a shipbuilding company, illustrating the virtual cell production scheduling problem under the proposed unit-based virtual blocking flow problems, the results show this theory feasibility and effectiveness of this research program.