Research On Vehicle Routing Problem With Stochastic Time For Z Company

Under the ear circumstances of economic globalization and Internet +,intensified competition among enterprises,resource consumption,rising labor costs,etc.,companies compressible cost space gradually reduced,so that the third profit source-logistics has attracted more and more attention,its position in the social economy is increasingly important.Distribution is an important link in the process of logistics,and the proportion of the cost of distribution in the total logistics cost is relatively high.Reasonable arrangements for distribution activities,selection of efficient delivery routes,can reduce logistics costs,improve service quality,to further increase the competitiveness of enterprises.The core issue of the logistics distribution is the distribution route optimization problem,namely the vehicle routing problem.In this paper,the Z e-commerce enterprise in Nanjing logistic center distribution activities as the research object,on the basis of the actual situation of enterprise,on the basis of traditional vehicle routing problem considering each vehicle the longest travel time and time window constraints,in delivery route also need to consider pick up(return)problem.And in real life,vehicle travel time affected by weather,accidents and other uncontrollable factors present random state,studied with time windows and delivery,pick-up vehicle routing problem with stochastic time.In order to meet the actual situation of the enterprise,the time windows and the longest travel time are considered to satisfy a probability constraint,and the two stochastic constraints are transformed into deterministic constraints by using statistical knowledge.According to the model,considering the advantages and disadvantages of each algorithm,the genetic algorithm is used to solve the problem.Using Matlab as the operating environment,the results of optimization are compared and analyzed.There are differences under probability levels to optimize the value and high level of probability(time-critical)delivery costs higher than the low level of probability distribution of costs.Compared with the actual distribution of enterprise,optimized delivery routes reduce distribution costs,improve vehicle utilization and distribution efficiency.Those increase the enterprise profit space and competitive advantages.