Research On Location-Inventory-Routing Problem Of Emergency Logistics Under Disruption Risks

In order to reduce the losses caused by emergencies,research on emergency logistics has now become a research hotspot at home and abroad.Public emergencies such as SARS in 2003,the Wenchuan earthquake in 2008,and the new crown epidemic in 2019 have posed challenges to China’s emergency logistics.From the perspective of emergency logistics,when an emergency such as an earthquake occurs,the disaster site needs a large number of emergency materials,and it is very important to deliver emergency materials to each demand point quickly and accurately.Therefore,reasonable site selection of emergency logistics distribution centers,determination of the optimal inventory of emergency logistics distribution centers,and timely arrangement of the driving routes of emergency material transportation vehicles can improve rescue efficiency.At present,the research of emergency logistics mainly includes site selection problems,inventory problems and route problems.Site selection,inventory,and path are closely related,and studying a problem alone will lead to the sub-problem being optimal and the overall sub-optimal.Therefore,this paper integrates the strategic layer decision-making(location selection decision),tactical layer decision-making(inventory control strategy),and operation-layer decision-making(vehicle path planning)in the logistics system,and studies the emergency logistics site selectioninventory-path problem.The main research contents of this paper are as follows:(1)The demand urgency of the disaster points was analyzed,the analytic hierarchy method combined with the entropy weight method was used to determine the index weight,and the improved TOPSIS method based on the B-type correlation degree was used to rank the demand urgency of the disaster points.The traffic capacity of roads in the disaster area was analyzed,and the road grade,length of road section and topography were taken as factors affecting road traffic capacity.(2)Aiming at the emergency logistics location-inventory-routing problem,considering the randomness of the demand of the disaster point,the interruption of facilities and road damage in the distribution center,etc.,the emergency logistics location-inventory-routing problem model is established,aiming at the minimum total cost expected by the system and the shortest total delivery time of emergency materials.Considering that the research problem belongs to NP-difficult problem,in order to solve it quickly,a two-stage heuristic algorithm is proposed for the proposed model.(3)Taking the 2008 Wenchuan earthquake as the background,the study was constructed by combining some real data and simulation data,and the final emergency logistics distribution center location scheme,optimal inventory and rescue vehicle path planning were obtained by MATLAB2014 b programming.The effectiveness of the proposed model is verified by comparing the results of considering the interruption risk with not considering the interruption risk,and finally the sensitivity analysis is carried out by adjusting the service level parameters of the emergency logistics distribution center,which provides a certain reference for the actual emergency logistics decision.