Research On Optimization Of Pharmaceutical Collaborative Delivery Routing Problem Based On Time Window Constraints

Logistics and supply chain are important content of production and life in modern society.The “The 14 th five-year plan and the long-term goals for the year 2035” calls for accelerating the construction of a modern logistics system,especially the “14th Five-Year” Cold Chain Logistics Development Plan for China’s cold chain logistics.The high-quality development of chain logistics in agricultural products,aquatic products and pharmaceutical products has clarified the top-level design and system guidelines.The pharmaceutical industry is an important part of the national economy,and pharmaceutical logistics has become a hot issue in the field of pharmaceutical circulation.Therefore,it is of theoretical value and practical significance to study the optimization problem of pharmaceutical collaborative distribution path.Firstly,by sorting out the development process and characteristics of China’s pharmaceutical logistics industry,this paper continues to pay attention to the uniqueness of the field of pharmaceutical logistics and distribution,and conducts related research at home and abroad from three aspects: vehicle routing problem,logistics distribution routing optimization and pharmaceutical logistics distribution system.Systematically sort and summarize current progress in research.Secondly,according to the characteristics of different drug distribution,the general drug distribution model and the cold chain drug distribution model are constructed respectively.Among them,the general drug distribution model is a vehicle routing problem with the objective function of minimizing the sum of dispatch cost and driving cost;the cold chain drug distribution model is a model for the distribution of new coronary pneumonia vaccines according to the latest document regulations.Pick-anddelivery vehicle routing problem in which the total delivery time is minimized as an objective function.The cold chain drug distribution model is proposed based on the current reality of medical logistics and distribution.Thirdly,according to the characteristics of the constructed general drug distribution model and cold chain drug distribution model,combined with the advantages and disadvantages of particle swarm algorithm and variable neighborhood search algorithm,from the representation of the solution,the choice of inertia weight,particle screening strategy and the design of neighborhood structure,the algorithm is designed.And the two algorithms are combined into a hybrid particle swarm algorithm(PSO+VNS algorithm),which is used to solve the vehicle path optimization problem of medical logistics distribution.Finally,65 examples of testing the VRPSPDTW problem are used to verify the general drug distribution model.Through the comparative analysis of the calculation results,it shows that the designed PSO-VNS algorithm has certain advantages,especially applicable to solve the problem of vehicle routing in the field of pharmaceutical logistics.At the same time,using the actual calculation example data of a pharmaceutical logistics distribution center in a city to customers in the city,the cold chain pharmaceutical distribution model is verified,and its importance is examined by discussing the different situations of the standardization of the distribution process.Further sensitivity analysis is carried out on the important parameters in the model,and relevant decision-making suggestions are put forward for pharmaceutical logistics service providers according to the analysis results,with the goal of completing the distribution task more efficiently.The research conclusions have practical significance.