A Research On Route Planning For Supplier-Supermarkets Logistics With Consideration Of Three-Dimensional Packing

The retail service in supermarkets is one of the most closely related commercial activities to people’s daily lives,and supplier-supermarkets logistics plays a vital role in supporting this service.The quality of the routing scheme during suppliersupermarkets logistics distribution process determines the efficiency of transportation and the level of logistics costs.A well-designed packaging scheme can avoid issues during loading and unloading processes,improve efficiency,and reduce docking time.Therefore,to reduce urban supplier-supermarkets logistics transportation costs while improving loading and unloading efficiency,it is necessary to consider the joint optimization problem of routing and three-dimensional packing.The joint optimization problem of routing and three-dimensional packing has practical significance in various logistics scenarios.However,this research is still in its early stages,with less focus on practical applications and more on theoretical studies.Therefore,introducing the joint optimization problem of routing and three-dimensional packing into the context of supplier-supermarkets logistics and proposing research on supplier-supermarkets logistics routing considering three-dimensional packing is necessary.Both routing and three-dimensional packing,which are the two sub-problems of the joint optimization problem,are classic combinatorial optimization problems and NP-hard problems.When combined,the problem becomes even more complex.Existing research approaches for the joint optimization problem of routing and threedimensional packing can be classified into two categories: "packing-first,routingsecond" and "routing-first,packing-second." Considering the characteristics of supplier-supermarkets logistics and the company’s requirements for cost and loading/unloading efficiency optimization,a mathematical model is established with the objective of minimizing logistics costs and incorporating geometric constraints and last-in-first-out constraints.A hybrid heuristic algorithm is then designed based on the "routing-first,packing-second" approach to solve this problem.In the algorithm design part,the 3D-RSOGA algorithm is constructed by combining the approximate optimal algorithm-an improved genetic algorithm based on POX crossover-with the three-dimensional packing algorithm optimized for residual space.The improved genetic algorithm outputs a set of routing solutions as input for the three-dimensional packing algorithm,which generates packing feasibility feedback.In the case analysis part,real data from Company R is integrated,and the 3DRSOGA algorithm is applied to obtain routing and three-dimensional packing solutions.Compared to Company R’s original routing scheme,the routing solutions generated by3D-RSOGA require the use of 2 fewer vehicles,reduce travel distance by 883.479 kilometers,decrease logistics costs by 1470.1877 yuan,and improve the average space utilization of the vehicles by 8.46%.Additionally,the packing scheme provided by the algorithm serves as a pre-packing plan for Company R,enhancing loading and unloading efficiency to a certain extent.Therefore,3D-RSOGA has proven to be helpful in optimizing supplier-supermarkets logistics routing and improving loading and unloading efficiency.The thesis has 37 figures,11 tables and 84 references...