Study On Integrated Optimization Model And Algorithms For Fresh Product LIP And LIRP Considering Direct Delivery Mode

With the advent of China's new consumption era,the consumption pattern has opened up a new pattern,and quality consumption is highly sought after.Affected by the new consumption boom,fresh enterprises are also constantly transforming and upgrading,and emerging fresh food channels such as fresh supermarkets are gradually growing.The fresh supply chain has the characteristics of high distribution cost,difficulty in storage,and high product loss rate.This makes most of the companies involved in fresh foods at a loss.How to control the cost of supply chain,it is particularly important to integrate and optimize the location,inventory and routing of fresh supply chain.Based on this background and modern fresh supply chain system represented by supermarket,this paper integrates the advantages of the direct delivery mode and the unified distribution mode of distribution center and proposes a fresh supply chain network considering direct delivery mode,that is,cross-level direct delivery is allowed in the supply chain network.And we conducts an integrated optimization study on the fresh product location-inventory problem and location-inventory-routing problem considering the direct delivery mode.Firstly,this paper studies the location-inventory problem of fresh products considering the direct delivery mode.In the three-level supply chain network,we consider the loss of the fresh product circulation between the two nodes,two-level inventory of distribution center and retailer,the demand relationship between the retailers and the direct delivery mode,and establish the fresh product location-inventory model?The goal of model is to minimize the total cost of supply chain system(including facility cost,inventory cost,transportation cost,and freight loss cost).In order to solve the model,the mixed integer nonlinear programming model is transformed into a mixed integer quadratic programming model.Then we use CPLEX to solve it and the model is coded on GAMS.And we analyze and compare the supply chain network considering the direct delivery mode and the supply chain network not considering the direct delivery mode by examples.Research shows that compared with the supply chain network without considering the direct delivery mode,the supply chain network considering the direct delivery mode has more cost advantages,the total system cost is reduced by 6.38-16.93%,and when the single order cost and the unit inventory cost is lower,and the unit cost of end distribution is not much different from the unit cost of trunk transportation,and the loss rate is large,the cost advantage of the supply chain network considering the direct delivery mode is greater.Secondly,based on the study of fresh product location-inventory problem considering direct delivery mode,we integrate vehicle routing problem into location-inventory problem and further study fresh product location-inventory-routing problem considering direct delivery mode.Considering the time window and vehicle capacity,we establish fresh product location-inventory-routing model.The goal of model is to minimize the total cost of supply chain system(including facility cost,inventory cost,transportation cost,and freight loss cost,penalty cost and shortage cost).Then two-stage heuristic algorithm based on simulated annealing is designed to solve this problem.Finally we analyze and compare the supply chain network considering the direct delivery mode and the supply chain network not considering the direct delivery mode by yogurt supply chain of YH supermarket in Beijing.Research shows that compared with the supply chain network without considering the direct delivery mode,the supply chain network considering the direct delivery mode has more cost advantages,the total system cost is reduced by 31.1%,especially in terms of transportation cost and freight loss cost,reduced by 30.7%and 69.4%respectively.In this paper,the integrated optimization of fresh supply chain considering direct delivery mode is studied.On the one hand,the research field of integrated optimization of fresh product supply chain is expanded.On the other hand,the advantages of the distribution mode considering direct delivery mode in fresh supply chain are analyzed and verified,which provides management decision basis for fresh enterprise operators.There are 36 figures,25tables,and 71 references.