Inventory Replenishment Planning of a Distribution System with Warehouses at the Locations of Producers and Minimum and Maximum Joint Replenishment Quantity Constraints

Abstract : In this paper, an inventory replenishment planning problem in a three-echelon distribution system of Alibaba is studied. In addition to central distribution centers and front distribution centers, this system also has warehouses at the locations of producers. Multiple products are jointly replenished with minimum and maximum joint replenishment quantity constraints. Transshipments between distribution centers/warehouses are allowed. This problem, which is to determine the replenishment quantity of each product between any two inventory locations in the system, is formulated as a bi-objective optimization model that aims at finding a tradeoff between overall service level and total logistics cost of the system. This model is solved by applying an augmented ɛ-constraint method. The effectiveness of the model is demonstrated by numerical experiments generated from the data of Alibaba. The results show that having warehouses at the locations of producers can lead to lower logistics costs with a given customer service level.