Research On Cold Chain Locationdelivery Design With Time Windows

With the rapid development of the logistics industry, the demand of cold chain products also increase, which stimulates the cold chain logistics. A main characteristic of cold chain products is that the products’ quality will decline as time pass and temperature change. Otherwise, the loss of cold chain products during the course of production and circulation is tremendous and hardly avoided. Therefore, optimization of cold chain logistics, as an outstanding problem in reality, needs to be addressed. The key issue of cold chain logistics is how to minimize the loss to ensure the delivery quality within a low cost of the whole logistics network. Although China’s economic is in a boom period, the cold chain logistics industry is still immature. This dissertation mainly focuses on the optimization of cold chain logistics network.Based on modeling and simulation, a dual-location optimization problem of cold chain logistics network is studied. Previous researches on cold chain logistics network are mostly confined to the location of distribution center, barely takes dual-location problem into consideration. Therefore, the dissertation raises a dual-location issue which includes the location of both manufacturing center and distribution center. First, several manufacturing centers and distribution centers are chosen from the alternative sites. Second, within the rule that the retailers in one area can be only served by one distribution center, a distribution time schedule is formulated based on the sites and routes that determined in the former step, while time windows are considered too. In view of traffic factors, it is difficult to estimate the delivery time. Hence a normally distributed random variable is added to replace the delivery time. Finally, the average departure time of simulation is computed and taken as the optimal departure time.In the process of research on cold chain logistics network optimization, I have consulted many literatures. To the location problem, vehicle routing problem, site selection and distribution problem, I have made various comparison and analysis. Set up two models, then solution and simulation. In the previous studies, there has been no simulation of product distribution in the departure time. However, selecting a time point or a period of time for distribution helps to save the time cost in practice. There is a lot of significance to research on the starting time of cold chain products delivery. It can reduce the spoilages of the cold chain products which distribution on the way and sent the fresh products to the customer.