| In recent years,China’s logistics industry has developed rapidly,and logistics has become an important support for the development of China’s national economy and a bridge and link connecting all parts of the national economy.But at present,the total logistics cost in China is still on the high side.From the perspective of the components of the whole logistics cost,the transportation cost accounts for more than 50%,accounting for a large proportion.Moreover,in the field of urban logistics distribution,customer demand is more dispersed and the situation is more complicated.The traditional closed distribution mode may have the situation that the last customer point is too far away from the distribution center,thus increasing the driving distance of vehicles on a single line and leading to high distribution cost.At the same time,it can be seen from the epidemic period that logistics enterprises lack the distribution ability to deal with emergencies,and the logistics distribution system is not perfect enough.Therefore,it is of great significance to optimize the logistics distribution link reasonably.Company A is a third-party logistics company,which mainly provides rice,flour,grain and oil distribution services for most supermarkets in J city.This paper takes Company A as the research object.First,through on-the-spot investigation and analysis of the existing distribution scheme,it is found that Company A adopts a closed distribution mode,and the distribution centers are independent of each other,and there are some problems in the distribution of Company A,such as unscientific route arrangement,unbalanced vehicle loading and high distribution cost.Secondly,in order to solve these problems,after analyzing the objective function and constraint conditions of the distribution route problem of Company A,this paper establishes a multi-center closed distribution route optimization model and a multi-center semi-open distribution route optimization model with the goal of minimizing the total distribution cost.Thirdly,because the distribution route optimization problem in this paper is more complicated,the solution scale is larger,and considering the operational efficiency and other factors comprehensively,this paper chooses genetic algorithm to solve it.Considering the shortcomings of traditional genetic algorithm,this paper improves its three processes of selection,crossover and mutation,and puts forward a decoding method based on the principle of minimizing the sum of the distances between the first and second customer points and the distribution center,which enhances the local search ability of the algorithm.Finally,this paper uses the traditional genetic algorithm and the improved genetic algorithm to solve the models under the two distribution modes respectively,and compares and analyzes the distribution schemes before and after optimization,thus verifying the effectiveness of the improved genetic algorithm and the feasibility of the semi-open distribution mode.Through the analysis of the optimization results,it is found that after the original scheme of Company A is optimized,the total driving distance of vehicles is shortened,the number of vehicles used is reduced,and the average vehicle loading rate is improved.Moreover,by comparing the optimization schemes under the two distribution modes,it is concluded that the semi-open distribution mode can further shorten the distribution distance,reduce the distribution cost and further improve the distribution service on the basis of the traditional distribution mode. |
