外文翻译--库存控制在多级供应链中的应用(编辑修改稿)

外文翻译--库存控制在多级供应链中的应用(编辑修改稿)内容摘要：

ccur at the retailers,but not at the warehouse) Parameters M a large positive number Ai fixed ordering cost at node i hi holding cost per unit period at node i hiti per period unit holding cost in transit from a source node to node i gi unit transportation cost from a source node to node i sltiunit lostsale cost at node i in period t dti mean customer demand of the product at node i in period t(note that customer demandoccurs only at the retailers,but not at the warehouse) Sti standard deviation of demand over the lead time plus the review period at node i in period t Li constant transportation lead time for transportation to node i IEt=0i initial inventory at node i Objective function The objective function is to minimize the total expected cost prising of ordering cost,holding cost at the warehouse/retailers,holding cost in transit,transportation cost,and lostsale cost. The first term in Eq.(1)is the ordering ordering cost is obtained from the multiplication of ordering cost Ai and binary variable second andthird terms express the holding costs at both the warehouse(i?0),the holding cost is calculated based on the ending inventory because the inventory reduces at the beginning of a period and remains constant during the the retailers(i40),it is calculated from the average of beginning and ending inventories because the inventory reduces due to the arrival of customers which may occur any time during the fourth term is the holding cost in fifth term is the transportation cost and the last term represents the lostsale cost. Constraints stock policy constraints:The ending inventory at each node must not be lower than the required safety stock level as presented in constraint(2) It is noted that the safety stock factor ki is a decision is determined by a simulationsearch approach as presented in Section safety stock factor ki is very important because it has a large effect on system inappropriate number of ki can result in poor system performance(low system fill rate with high system cost). balance constraints:The beginning inventory level is equal to the ending inventory level of last period plus the total ining ending inventory level is equal to the beginning inventory level minus the total outgoing quantity cost constraint:Since transportation occurs after an order has been placed from a destination to its source,the fixed ordering cost is always incurred when transportation occur,the binary variable Bti equals 1 if the transportation amount Tt i is not zero and binary conditions: Bti is binary 8t。 i. (7) The proposed mathematical model is linear and can be solved to the model,the planner obtains the optimal IDP describing the optimal transportation amount and optimal inventory level at each node in each mean values of the stochastic variables(demand per period and per retailer) are entered into the MILP model,following the IDP may not result in the real minimum total practice,the actual demand might be different from the mean shortage and excess of inventories may occur,which can result in unforeseen lost sales and inventory holding ,the actual amount of inventories and transportation in the real system may differ from the related quantities in the this paper,the oneperiod rolling horizon planning strategy is this case,the planning horizon is divided into a certain number of planning optimal plan for the first period is used for controlling the operations of the supply chain, and at the end of the first period,the state of the system is updated and the planning is repeated with the horizon advanced by one explanations of the oneperiod rolling planning strategy can be seen in Jung et al.(2020). stock policy The optimal IDP will suggest the planner to send products to destinations to satisfy the customer requirements and safety stock thispaper,there are two stages in which the optimal plan must suggest the safety ,the safety stock policy is denoted by[K1,K2],where K1 and K2 represent the safety stock parameters at the warehouse and retailers,respectively(K1?ki?0 and K2?ki,where i40).Since it is assumed that all retailers are identical,the ki values are the same among all retailers(i40). The safety stock is kept to protect against the demand ,it is related to the system fill system can give the desired fill rate if suitable safety stock amount is kept at the right ,the determination of the most suitable safety stock policy,which can give the required system fill rate and minimum total cost,is a major issue of using the IDP control this paper, the most suitable safety factor policy is determined by searching the safety stock policy[K1,K2]which can give the desired fill rate and the lowest total searching process is operated as follows. Set K1 in a range from 0 to with a step size of (0。 0:1。 0:2。 ...。 3:0).For each value of K1,search for the valueof K2(using the same range as K1)which gives the desired fill rate and the lowest total cost using a simulation experiment(see Section 6).To save putation time,the step size inthe searching process may not be too this paper,the step of is used. echelonstock R,s,S control system The effectiveness of the IDP control system will be evaluated against a classical periodic review IDP control system can be viewed as aperiodic review system wherethe review period R is one period because the optimal IDP is regenerated every e order size of the IDP control system is variable depending on the remendation fromthe optimal IDP control system utilizes the work information rather than local ,a classical inventory control system which is similar to the IDP control system is the echelonstock R,s,S control policy(whereR?1).This control policy is thoroughlydescribed in Whybark and Yang(1996).The brief expl。