Disruption Management For Distribution Vehicle Scheduling With Time Window Changes

Logistics distribution is an important business link in the whole logistics system.It is highly related to the operational effectiveness and efficiency of a logistics company.In the realistic logistics distribution activity,the vehicle distribution system are usually affected by many disturbances,such as traffic congestion,vehicle breakdown,traffic accident and weather change.There is a kind of disturbances that comes from customer's uncertainty,which mainly manifests as the change of customer's demand,time window and delivery location.As people's pace of life gradually accelerates,the time uncertainty is becoming higher and higher.Therefore,it is an important problem that logistics companies are facing that how to respond to the customer's time window change timely and effectively,and in the mean time,to reduce the influence made by the time window change as far as possible.Disruption management is a methodology that can deal with interference incidents in real time.It aims at minimizing the disturbance degree on original distribution system made by the interference incidents.This paper applies the disruption management methodology,and carries out a research focusing on the vehicle scheduling problem with time window changes.The main researches are as follows:(1)When the time window changes,this paper makes a judgment whether it may exert an influence on the current distribution plan.The change is analyzed from two aspects including the advancement and postponement of the time window.Then the identification condition is determined.The disturbance impact of time window change is measured from three aspects including the path,cost and service time.From the path aspect,two different situations are considered.(2)According to above measurements,the generalized cost deviation is proposed.Then a disruption management model is established aiming at minimizing the generalized cost deviation.A good original distribution plan is generated by the improved genetic algorithm this paper designed.In order to solve the disruption problem quickly and effectively,a vehicle dispatching algorithm based on tabu search is devised according to the proposed model.(3)The comparison and analysis of the numerical results verify the advantages of the proposed method.In addition,this paper selects six cases from Solomon standard test instances and makes sensitivity analysis for the unit time value coefficient.It is found that the proposed model has a general applicability to different kinds of goods.The proposed disruption model and dispatching algorithm consider the disruption's impact on three aspects comprehensively,which are logistics cost,service time and path change.They can reduce the disturbance caused by time window changes effectively and ensure the service quality.This paper provides some decision making support on responding time window changes in the process of distribution for logistics companies.