Research On Just-in-time Material Distribution Of X Company’s Production System

X Company is a production system of multi varieties and low volume production,which is the production system based on the center of the assembly station.So,the material distribution system is very important for manufacture system.Material delivery too early can lead to accumulation of materials on production line,Material delivery too late or insufficient quantity of material can cause the material shortage and production line shutdown.These factors always lead to decline in the quality of products and the increase in manufacturing cost of products.This paper mainly studies the just-in-time material distribution problem of assembly production line;concerning with JIT concept and company’s actual situation,base on the BOM of product and assembly process,material must be sent to the assigned workstation before the beginning of the production.A mathematical programming model is established for the three stage of the distribution of vehicle capacity constraints,the shortest transport path and the minimum distribution vehicles.Use the classic three stage optimization model of heuristic algorithm to achieve the most economic production demand cycle.Firstly,the paper divides the production time into several equal production requirement cycles,calculating the minimum quantity of distribution vehicles of each production requirement cycle,getting the specific workstation of each distribution vehicles and the volume of delivery material of each workstation.Secondly,vehicle routing optimizations to shorten the vehicle travel time of every delivery train.The delivery time is sum of both travel time and handling time,because of handling time fixed,so the minimized deliver time is to minimize the travel time.Finally,in the case of minimization delivery vehicle,material distribution will be assigned to the vehicle.If material delivery time of each production requirement cycle is less than the time of production requirement cycle,it’s needed to further reduce the production requirement cycle to calculate the material delivery time of each production requirement cycle.The relevant models are established and research methods to solve the model.Use the partial optimization method to solve global optimization problems.Using three stages heuristic algorithms to get the minimum quantity of distribution trains optimize the vehicle route and calculate the time of material delivery,Complete the vehicle assignment under the condition of limit resources,Obtaining the minimum production requirement cycle and the minimum inventory level.Calculated by analyzing a local optimum to achieve global optimum and do practical case to verify the validity of the algorithm.