Simulation Optimization Of The Steel Product Supply Chain Inventory Based On ExtendSim

Inventory is the most important part of supply chain management,which accounts for the entire supply chain operating costs more than 30%,some industries up to 70%,or even higher.Reasonable inventory control can not only make the inventory funds of whole supply chain occupied less,but also sufficient to deal with the severe market fluctuations,emergency in customer demand and production and transportation.However,due to the randomness of market fluctuation,production transportation and so on,the current enterprise inventory holding level is very high.Although the global supply chain collaborative management model has taken shape,making global optimal inventory control strategy faces big challenges due to random factors.So enterprises in the supply chain are still using single-level inventory control mode.Therefore,the study of multilevel inventory control in supply chain is of great practical significance.Based on the project of a steel enterprise,this paper takes the supply chain of steel products as the research object,abstracts the two-echelon inventory problem and analyzes it synthetically.Firstly,the stochasticity of supply chain,such as lead time and demand quantity,is analyzed and probability distribution is used to describe the stochastic two-echelon inventory model.Secondly,because of too many optimization parameters,the EOQ economic batch order model is introduced to simplify the inventory cost model,and the one-dimensional search method is used to solve this problem.Since using analytic method to solve the optimal inventory control problem cannot perfectly describe the dynamic characteristics of the supply chain and the solution process is cumbersome,we propose a solution to solve these problems by using system simulation and optimization.Based on the ExtendSim software,a discrete event simulation model of two-echelon supply chain is constructed.And then,the optimal inventory control strategy of supply chain is solved by genetic algorithm combined with the system simulation model.At last,the optimal inventory control strategy which is solved by mathematical analytic method and system simulation optimization method is evaluated by the discrete event simulation model.A large number of simulation experiments show that both inventory control strategy can achieve a good control effect of the inventory,but using the inventory control strategy calculating by system simulation optimization method can achieve lower inventory operating costs and better control effect,which indicates that it is feasible and effective to use the system simulation optimization method to solve the inventory control strategy.