Research On Vehicle Scheduling Problem With Multiple Retailers And Multiple Trips In Urban Logistics Distribution

As the key supporter of e-commerce,urban logistics distribution has become an important factor to win the O2 O competition.Based on this,some retailers operate in a predetermined mode to ease distribution pressure and use exclusive or sharing logistics service mode to reduce the total cost of distribution.However,the urban logistics distribution is still in the stage of extensive development,and retailers lack theoretical suggestion for the choice of logistics mode currently.It is significant to study this logistics distribution problem.This problem is abstracted as Vehicle Scheduling Problem with Multiple Retailers and Multiple Trips in Urban Logistics Distribution: A fixed number of vehicles pick up goods from multiple retailers and deliver to a number of customers.Each customer is associated with a preferred delivery time and goods is associated with a maximum delivery period limit.A vehicle must pick up goods from a specific retailer firstly and then deliver to customer.Vehicle can perform multiple trips.This problem has characteristics of multi-trip and pickup and delivery vehicle routing problem.Meanwhile it requires to get scheduling plan rapidly.It is complex and difficult to solve by introducing constraints of multiple pickup locations.This thesis studies the solving algorithm and service modes for the Vehicle Scheduling Problem with Multiple Retailers and Multiple Trips in Urban Logistics Distribution.The main research work are as follows:A two-stage heuristic algorithm is designed to solve the problem according to logistics service modes.The first stage is to construct initial solution matched with the logistics service modes.The second stage is to optimize the initial solution by adaptive large neighborhood search(ALNS)and tabu search(TS)algorithm respectively.Three logistics service modes are investigated to provide suggestion for retailers and logistic companies.Computational experiments were carried out on test instances modified from Solomon's benchmark instances.Experimental results demonstrate that,ALNS can get good solution at extremely low time cost comparing with TS.Sharing service mode outperforms exclusive service generally,but the cost of time is much higher.