| With the improvement of people's living standards,the concept of healthy life of the general public has gradually changed from “curing the disease” to “preventing disease”.Changes in the concept have given rise to the rapid development of the vaccine industry.For the rising vaccine manufacturers and vaccine wholesalers,the issue of site selection for vaccine warehouses is a strategic decision at the enterprise level,which directly affects the operation of the company.Many factors affecting the location of vaccine warehouses will often change,especially the demand for each vaccine demand area.For decision makers of vaccine warehouse location,the demand for analysis of vaccine demand areas can only be obtained through historical data and market research.When these data are often inaccurate,the difficult predictability of demand for this type of vaccine demand often increases the difficulty for decision makers to make optimal decisions.This paper aims at the problems in vaccine storage site selection,based on the uncertainty of the demand for vaccines in the region,with the goal of minimizing the total cost.Research was conducted to establish a robust site selection model for two kinds of vaccine warehouses,a single-stage vaccine warehouse location and multi-stage vaccine warehouse location,which provided a certain guiding role for decision makers to make the optimal decision for vaccine warehouse location.The main research contents of this paper are as follows:(1)Based on the "Regulations on the Administration of Vaccine Circulation and Vaccination" of China,this article briefly analyzes the procurement,distribution,and supervision processes of the first class vaccine and the second class vaccine at the present stage in China.At the same time,by analyzing the main factors affecting the location of the vaccine warehouse,this paper summarizes the cost factors considered and quantifies these cost factors into mathematical words that can be used to build models.(2)A model for single-stage vaccine warehouse location was constructed.After considering the refrigeration cost,transportation cost,warehouse cost,and various maintenance costs,a single-stage vaccine warehouse location model was constructed by taking into account the uncertainty of demand at each vaccine demand point in the actual situation.Using the "box" uncertainty set and the "ellipsoid" uncertainty set to describe the uncertainty of demand,two robust inventory selection models based on demand uncertainty for vaccine storage are constructed.Then,through the randomly generated examples,the advantages and disadvantages of the two robust models in single-stage vaccine warehouse location were analyzed.(3)A model for multi-stage vaccine warehouse location was constructed.Due to the high temperature requirements for vaccine transportation and storage,and the large differences in temperature throughout the year,this article will set the vaccine storage site selection cycle to one year,and each cycle will be divided into four phases by quarter,and each phase.Have decisions on whether to replenish.In addition to refrigeration costs,transportation costs,etc.,factors such as inventory costs and replenishment costs were comprehensively considered,and a multi-stage vaccine warehouse location model was established.And based on the uncertainty of the demand demand of vaccine,with the goal of minimizing the total cost,a robust selection model of "box" and a model of "ellipsoid" robust location were established by robust transformation.At the same time,it is verified that the “box” robust location model is a mixed-integer linear programming model,the “ellipsoid” robust location model is a second-order cone programming model,and a multi-stage vaccine is analyzed through a randomly generated calculation example.Some management implications of warehouse location provide some suggestions for decision makers. |
