An advanced optimization method of two-echelon spare parts inventory control system with horizontal replenishment for enhancing supply efficiency

Aim. Our method is, in our opinion, advanced in the sense that it is better than existing methods that we know in the open literature. The inventory control system we deal with includes one center warehouse and one distributive inventory control system with n sub-warehouses. In section 1 of the full paper, we explain the symbols used. Section 2 points out that the distributive inventory control system optimization model, which considers random horizontal replenishment of spare parts in sub-warehouses, can give an optimal set of inventory control parameters (Si, si) based on the shortest path-optimization algorithm for horizontal replenishment with service level constraints. In section 3, we establish the center warehouse's inventory control parameters (Q, s) optimization model using multiple linear regression. In section 4, we perform the numerical simulation of our optimization method. The simulation results, given in Tables 1 through 7 and Figs. 1 and 2, show preliminarily that the optimization method is effective for reducing inventory costs of spare parts and the fluctuation of orders while enhancing service level. The simulation results also show preliminarily that our method, compared with other optimization methods without random horizontal replenishment, is advanced.