Abstract: With the popularity of “Internet+healthcare”, small medical institutions cooperate with pharmaceutical e-commerce to purchase medicines in small batches frequently to reduce their own inventory costs. In order to ensure the timeliness of medicine delivery, order splitting can easily happen in pharmaceutical e-commerce, which not only increases the distribution cost of logistics of e-commerce enterprises, but also reduces customer satisfaction. In order to improve the logistics efficiency of pharmaceutical e-commerce and meet the demand of instant medicine delivery, a dynamic order distribution model of pharmaceutical e-commerce is established, which not only considered the dynamic update of inventory information, but also considered the optimization strategy of order information update and reallocation. The dynamic update of inventory information (DIIO) algorithm isdesigned and dual optimization of information update (DIDO) algorithm is designed to divide the dynamic problem in the planning cycle into multiple static sub-problems. First, the greedy algorithm is used to generate the initial solution, and then the integer programming model is used to get the optimal solution. In the process of constructing the initial solution, through order classification, the SKU demand of a single order is converted into inventory, which greatly improves the optimization space of multi-order allocation. Secondly, by recursively traversing the optimal allocation results of multiple orders, an accurate solution is obtained with high efficiency. Based on the analysis of the data of a pharmaceutical e-commerce B2B platform, the DIIO algorithm reduces the order splitting rate of pharmaceutical e-commerce by 29.45%, while the latter reduces the number of warehouse shipments by 50.41% through order reallocation, saving about 1.1541 million yuan in monthly distribution cost. In addition, through the sensitivity analysis of parameters such as the per capita order frequency and the number of SKUs in the order, both algorithms have good robustness. It not only alleviates the inventory pressure of small medical institutions, but also improves the logistics efficiency of pharmaceutical e-commerce, so as to achieve the goal of win-win.

Key words: order splitting rate; order reallocation; information update; pharmaceutical e-commerce