Study Of Vehicle Scheduling Problem With Customers' Distribution Requirements Change

Vehicle scheduling problem has always been an important problem in logistics distribution.Arranging reasonable vehicle distribution routes can improve service quality and reduce distribution costs effectively.However,the logistics distribution system is relatively complex and there are some uncertainties which affect the normal implementation of the logistics distribution business.Some of these uncertainties come from the delivery vehicle,such as vehicle failures,vehicle maintenance and some from traffic conditions,such as traffic congestion,sudden changes in the weather.Besides,these uncertainties maybe come from customers,such as changes in demand,changes in time windows,and so on.In reality,the vehicles may not be able to arrive at the service location within the agreed time window due to various emergencies or the original contracted demand cannot satisfy the current demand,so the customers have to temporarily change service time window or demand after the logistics distribution 'service has started,that is,customer delivery requirements have been changed.That requires logistics companies to respond to these changes of customer information in a timely manner.Logistics companies need to meet the service requirements and ensure the quality of service in order to minimize the degree of disturbance to the entire logistics distribution system.On the other hand,in the actual logistics distribution,there are some cases where the delivery service and the pick-up business of the logisticsdelivery vehicle are combined.That is,the vehicle carries out delivery and pick-up services at the customer's point at the same time.In the case of goods,the vehicle scheduling problem with simultaneous delivery and pickup with changes of customer delivery requirements is also an important issue worth studying.Vehicle scheduling problem is a NP problem and it is very difficult to solve.Therefore,how to deal with the vehicle scheduling problem with customer requirements change in logistics distribution effectively and minimize the impact of interference events on the original logistics distribution plan has become a key issue which logistics companies are concerned about.For this reason,this article has conducted in-depth research on the logistics vehicle scheduling problem with changes in customer delivery requirements.The main researches are as follows:Firstly,the vehicle scheduling problem with the changes of customer time window is analyzed.Based on the idea of disruption management,the disturbance measurement was carried out from logistics cost,service time and path change.And a vehicle scheduling disturbance management model is established under the time window variation with the goal of minimum departure from generalized cost.By analyzing the particularity of vehicle scheduling problem with simultaneous delivery and pickup respect to the general vehicle scheduling problem,a vehicle scheduling disturbance management model with simultaneous delivery and pick-up under time window changes with minimum deviation from generalized cost is established.Based on the results of time window variation disruption identification,a heuristic vehicle scheduling algorithm was designed to solve the problem.The result of the example verifies the effectiveness of the method.It can effectively generate the logistics dispatch vehicle scheduling scheme with the least disturbance.Secondly,the vehicle scheduling problem with changes in customer demand is analyzed.Based on the idea of disruption management,the article measures the disturbances from two aspects of logistics cost and service time to establish a vehicle scheduling disturbance management model with demand changes based on minimum deviation from generalized cost.By analyzing the particularity of vehicle scheduling problem with simultaneous delivery and pickup respect to the general vehicle scheduling problem,a vehicle scheduling disturbance management model with simultaneous delivery and pick-up under demand changes with minimum deviation from generalized cost is established.A heuristic vehicle scheduling algorithm was designed based on the results of demand variation disruption identification to solve the problem.The result of the example verifies the effectiveness of the method.It can effectively generate the logistics dispatch vehicle scheduling scheme with the least disturbance.Then,the vehicle scheduling problem under the simultaneous change of customer demand and time window is analyzed.To establish a vehicle scheduling disturbance management model with demand changes based on minimum deviation from generalized cost,the article bases on the idea of disruption management measures the disturbances from two aspects of logistics cost and service time.Unlike before,the article takes into account the waiting time factors of the vehicle at the customer location.By analyzing the particularity of vehicle scheduling problem with simultaneous delivery and pickup respect to the general vehicle scheduling problem,a vehicle scheduling disturbance management model with simultaneous delivery and pick-up under demand changes with minimum deviation from generalized cost is established.A heuristic vehicle scheduling algorithm was designed based on the results of demand variation disruption identification to solve the problem.The result of the example verifies the effectiveness of the method.It can effectively generate the logistics dispatch vehicle scheduling scheme with the least disturbance.Finally,the uncertainty of real-time customers in the process of logistics distribution is analyzed.By predicting the location and demand of customer points which may emerge in the distribution process,the logistics distribution can arrange vehicle scheduling,loading volume and arrive time are in advance so as to respond the needs of new customers quickly and serve as more customers as possible.This article looks the possible customer points as virtual customer points.Apply the principle ofPoisson process and consider the distribution needs of real and virtual customers at the same time to establish vehicle scheduling model with the goal of minimizing the total cost of expected distribution.An improved genetic algorithm is designed to solve the problem.The validity of the method is verified by an example.It can quickly respond tothe needs of new customers,which improve the customer satisfaction and service level.This paper considers the uncertainty in the logistics distribution process from two aspects.On the one hand,by using the idea of disruption management,the logistics vehicle scheduling problem with changes requirements is studied and the corresponding disruption management model is established.The solution algorithm was designed to solve the problem when disturbances occur.On the other hand,the Poisson process principle was used to study the vehicle scheduling problem based on the prediction of new customers.The corresponding vehicle scheduling model was established and the solution algorithm was designed before new customers emerge.The method of this paper can provide decision support for logistics companies to respond to customer uncertainty in the logistics distribution process.