Research On The Production Planning And Controlling Based On Theory Of Constraint Under Multi-Product And Small Lot-Size Production

With the advancement of the science & technology and the improvement of customers'requirements, the requirements of the efficiency, punctuality and flexibility become more and more important facing the fast changing market environment. Theory Of Constraint, proposed by doctor Goldrrat, is one of the most important theorys and methods. But for the complex hybrid production scheduling under multi-product and small lot-size environment, the bottlenecks are difficult to be identified and drifting with different products mix or tasks combination because of the stochastic features of manufacturing systems. Therefore, in practice, it is very difficult to determine the parameters of DBR scheduling method.In view of this, On the base of the study of theory of constraint, master production schedule, modeling and simulation optimization, the method of improved DBR production planning and controlling based on discrete event modeling and simulation optimization is proposed. The improved method first collects the production system data such as task data, process data and capacity data and builds the model of the production system using discrete event modeling and simulation software Flexsim, and then run the model to determine the location of bottleneck. After identifying the bottleneck, the parameters of DBR are determined and optimized through simulation and improved particle swarm particle optimization algorithm. At last the scheduling with DBR is implemented according to the optimized parameters.At last a specific scheduling example in HeFei HuiLing auto parts Co., Ltd is given. The results show that the improved DBR scheduling method can effectively overcome the weakness of original DBR, which is proven to be feasible and effective to increase the efficiency of system, lower WIP and shorten the production cycle.