Two-echelon Inventory Control Policy In Oil Supply Chain

Since China is the largest country in terms of car ownership,the normal supply of oil is particularly important as it is directly related to social stability.At present,the treacherous changes of international environment have reduced the profit margin of the oil retail system and also increased the degree of uncertainty in the supply and demand of oil.Therefore,from the perspective of the supply chain,reducing inventory cost on the basis of ensuring customer service level has become a key measure to maintain the normal operation of enterprises and society.This thesis focuses on a two-echelon supply chain consisting of an oil depot and all the gas stations in charge of the oil supply.At present,there are many problems in the inventory replenishment of the two-echelon oil supply chain,such as the lack of scientific decisionmaking process,the blind set up of safety stocks and inventory backlogs.Faced with these problems,this thesis puts forward the demand driven two-echelon inventory control policy under the premise of centralized control in the dispatch center.According to the actual investigation,this problem has the characteristics of fixed replenishment batches,high uncertainty and large batch demand,high fill rate requirements and large-scale.In view of the complexity of these characteristics,this thesis focuses on solving the following difficulties: 1)Based on the actual replenishment situation of oil,how to use the existing two-echelon inventory control theory to describe the two-echelon replenishment process and relationship of the oil depot and gas stations easily and efficiently;2)According to the characteristics of the practical problem,how to properly adjust the existing METRIC model to apply to this problem;3)From the perspective of practical application,focusing on the high fill rate requirements and demand characteristics,this thesis explores how management decision-makers make inventory control policy,and finally gives reasonable suggestions.In view of the characteristics and difficulties of the two-echelon oil inventory system,the following research work is carried out:(1)Analysis of the characteristics and complexity of the two-echelon oil inventory replenishment.Analyze the demand characteristics of the oil supply chain and the process of two-echelon replenishment,clarify the linkage replenishment logic of the oil depot and gas stations under the(R,nQ)inventory control policy and then analyze the complexity of solution brought by the problem characteristics.(2)Replenishment model and approximate solution method of two-echelon inventory control policy in oil distribution system.According to the system characteristics and METRIC theory,a two-echelon replenishment model with the minimum holding cost as the objective and the fill rate as the constraint is established and the METRIC model is adjusted by referring to the relevant research results.According to the characteristics of large-scale problems,the decomposition method is used to solve the approximate optimal control policies of the oil depot and gas stations step by step.(3)Numerical experiments and result analysis.Through field investigation and design of numerical experiments,explore the impact of demand and fill rate requirements on inventory control policy and make reasonable suggestions based on actual scenarios.This thesis proposes a reasonable solution to the two-echelon inventory replenishment problems with characteristics of fixed batch and large-scale in the distribution system and probes into the application method of inventory control theory in the actual situation.The conclusion can provide reasonable suggestions for management decision-makers to centrally control the two-echelon replenishment in oil system.