Flexible Urban Logistics Distribution Optimization Model And Algorithm

With the rapid development of logistics industry and the rising of living standards,the service quality is treated more and more important.But in the urban distribution,customer is more and scattered,and the accessibility of each node is limited to a certain extent.The customer requirements and time passing a road is uncertain.In all kinds of uncertain conditions,distribution enterprise how to make the cost lowest at the same time also can provide customers with timely and satisfactory delivery services.Namely how to make the delivery service have high flexible and have the ability to respond various uncertainty situation quickly and efficiently,it is an important problem facing the modern city logistics distribution.Based on this,the flexible urban logistics distribution optimization model is established,the goal is considered in the total distribution cost,the flexibility of delivery time,and the quantity flexibility of distribution center.The model is solved to use the analytic hierarchy process,clustering analysis,and genetic algorithm.Firstly,the status of domestic and foreign are summarized.According to the existing research results and shortcomings,the necessity and importance of research on flexible urban logistics distribution are obtained.The uncertainty in the process of distribution and the influence of uncertainty on distribution enterprise and customers are analyzed based on the characteristics of the urban distribution,and the flexible index is determined based on the uncertainty analysis.Secondly,the customer satisfaction function curve based on the hard time window is constructed.The function is constructed according to the time of vehicle arrival,the service time and time window.The curve of satisfaction is described according to the customer satisfaction function expressions.Thirdly,according to the uncertainty on the customer demand and distribution time,the service time window,and the maximum load capacity of distribution center and vehicles are considered,the flexible logistics distribution model is established.the goal have the lowest total distribution cost,the largest flexibility of delivery time,and the largest quantity flexibility of distribution center.The total cost including the fixed cost of the selected open distribution centers and the vehicle transportation cost.The flexibility of delivery time is measured with the rest of the lead time of all the distribution center.The quantity flexibility is measured used the residual goods quantity of all the distribution center selected.Factors considered in the model have service time window,the capacity of distribution center,the maximum load capacity of vehicles and others.Then,the model is solved by analytic hierarchy process,cluster analysis method andgenetic algorithm.First of all,the appropriate weight of each target is assigned by the analytic hierarchy process.Then,the distribution center is selected according to the distance between the distribution center and the customer,the maximum storage capacity of the distribution center and time window.Finally,the number of vehicles in each distribution center and the service path of each vehicle are optimized through the multi-chromosome genetic algorithm coded by non-repeated natural numbers.Finally,the example is solved,and the correctness of the model and the validity of the algorithm are verified through the analysis of the vehicle loading rate,distribution line and customer satisfaction.Model is presented and factors considered have the distribution center selection,time window limit,the distribution center capacity limits,vehicle capacity limits and so on.But there are some reality influential factors have been not considered,such as product type,vehicle model and so on.Therefore,it is necessary to improve the existing models and algorithms.