A Vehicle Routing Model For Third-Party Cold Chain Logistics Enterprises

With the social and economic development, the demand of fresh frozen foods is growing. Loss rate in the process of production, storage, transport and consumption of fresh products is up to20%, which is an alarming loss of circulation especially in the city. At the same time, retailers will ask for usual delivery time and delivery quality restrictive requirements in order to improve its level of sales. While, distributor, should also be considered to ensure the quality of the goods at the same time windows constraints, and reduce operating costs. How to reduce logistics costs as while as to ensure the quality of the goods and to meet customer requirements has become to the focus of many domestic and foreign theories and application scholars'attention. In cold chain, the distribution task is heavy, and the technique is demanding, so many supermarkets commission third-party logistics enterprises to carry out the daily fresh food distribution. Third-party cold chain logistics companies have a higher demand of the vehicle scheduling method in order to pursue the distribution of profit maximization, rational distribution of resources, reduce wear and tear of the distribution of fresh frozen foods.Theoretically the main types of third-party logistics vehicle scheduling vehicle scheduling problem with capacity constraints, multi-model vehicle scheduling problem, vehicle scheduling problem with time windows, back to the way transportation vehicle scheduling problem, the compatibility constraints vehicle scheduling problem the uncertainty of the vehicle scheduling problem, the parking lots open vehicle scheduling problem, a distribution center for vehicle scheduling problem eight kinds, the main research method contains the exact algorithms and heuristic algorithms. The exact algorithms are Branch and Bound, Cutting Plane Method, Dynamic Programming, ect. While heuristic algorithms are Savings Algorithm, Genetic Algorithm, Simulated Annealing Algorithm, Tabu Search Algorithm, ect. Various heuristic algorithms have their own advantages and disadvantages, given a few number of supermarkets and the growth characteristics of the Conservation Act as the basis for the algorithm is easy to extend and improve.This paper relies on the subject of "Beijing food cold chain logistics key technology R&D and demonstration" which is one of the Green Corridor projects held by Beijing Municipal Science and Technology Commission. Beijing Oriental Friendship Food Distribution Company and Puhua Supermarket are two companies surveyed in the subject. Beijing Oriental Friendship Food Distribution Company is a third-party cold-chain logistics enterprise and it offers Puhua supermarket stores'daily fresh food distribution. This paper does a research in vehicle routing models and proposes a new vehicle routing model and program for Beijing Oriental Friendship Food Distribution Company and Puhua Supermarket. In this paper, Beijing City's traffic, special policies of cold-chain logistics and transport and hardware facilities are studied. After the study, it comes to that two theories on third-party cold chain logistics and vehicle scheduling are needed. Then this paper proposes a saving algorithm based on C-K which is about single-warehouse multi-commodity multi-retailer vehicle routing model used by refrigerated trucks. Finally the model is instance validated.Savings algorithm proposed in this paper is proven based on the C-K single-warehouse multi-commodity and multiple retailers refrigerated trucks, vehicle scheduling model for vehicle scheduling in third-party cold chain logistics enterprises, the volume of different commodities, quality considerations, and detailed vehicle scheduling factors considered in the super-distribution of third-party cold chain logistics companies to provide methods for reference and guidance.