短缺量滞后供给与顾客等待时间相关的VMI模型

考虑短缺量滞后供给与顾客等待时间负相关,提出了供应商生产批量用于满足订货商多次订货需求的VMI模型.仿真寻优求得系统唯一最优解,短缺量拖后因子和生产率的灵敏度分析表明,二者对VMI系统库存控制策略的制定有较大影响.当短缺量拖后因子较大时,订货商应提高服务水平,缩短订货周期;当供应商生产率较大时,则应延长订货周期并减少生产周期内的订货次数.     

部分短缺量拖后且考虑最终产品变质的VMI模型

在无短缺量拖后或短缺量完全拖后的VMI模型基础上,进一步考虑缺货期间出现短缺量部分拖后的情况,建立了包括一个供应商和多个订货商、从原材料到产成品且最终产品出现变质的供应商管理库存（VMI,Vendor-Managed Inventory）模型,给出了数值算例和主要参数的灵敏度分析,结果表明顾客服务水平、丢单系数及最终产品变质率对供应链各成员的单项成本及集成总成本均有不同程度的影响,为VMI库存系统的管理决策提供了理论依据。     

梯形需求缺货部分拖后的变质物品EOQ模型

研究了变质物品在一般梯形需求率下和缺货部分拖后时的库存模型.假定变质物品的需求为一般形式的梯形需求率函数,允许缺货且缺货部分拖后,缺货拖后率是到达下一周期补货等待时间的凹函数,物品的变质率为一般形式的Weibull时变函数,根据一般梯形需求函数不同的参数取值,建立了不同情形下变质物品的库存决策模型,给出了每种情形下模型的最优订货策略.研究结果表明,库存系统最优库存减少为零的时刻不依赖于具体的需求参数,但库存系统的最优订货策略却依赖于具体的需求参数.     

供应商管理库存的价格效应研究

通过建立数学模型,论证了VMI在供应链中收益的非负性;在此基础上还给出了供求均衡价格与订货成本比、库存成本比的函数关系,该公式说明当订货成本比与库存成本比相差比较大时,VMI可以有效降低均衡价格,否则均衡价格将会上升。     

Weibull分布变质物品库存模型研究

研究了变质物品在考虑资金时间价值时的经济订货批量问题.假定物品的变质率服从两参数的Weibull分布,物品的需求率与库存水平有关,且为库存水平的线性函数,计划时域内进行多次订货,订货时间间隔相等,允许缺货且短缺量完全拖后,以库存系统的总费用最小为目标函数,建立了变质物品在存货依赖性需求下考虑资金时间价值时的最优订货批量模型,分析了模型存在唯一的最优解的必要条件,并且给出了在该条件下求解模型最优解的算法,最后给出了一个计算实例.     

随机需求时上游段VMI模式共赢条件

考虑实施上游段VMI模式后,订货（配送）主动权的转移导致订货（配送）策略的不同,以及制造商对各零部件需求速率的不同导致其对各零部件的订货周期也不一致的情况。假设外界需求随机,通过建立模型,结合模拟仿真,对实施上游段VMI模式前后各企业的经济效益进行比较,探讨实施VMI且制造商销售价格不变时,供应商是否存在合理的销售价格涨幅区间。该区间的价格既能弥补供应商因管理制造商零部件库存多消耗的成本,也能使制造商和供应商的经济效益都有所提高,实现共赢,为上游段VMI模式的推广提供理论依据。     

基于线性时变需求的鲜活农产品三级供应链协调

针对一个供应商-分销商-零售商构成的鲜活农产品三级供应链,基于线性时变需求,利用时间折扣契约实现了供应链的协调,并求出了使供应链各节点企业达到共赢的契约参数的取值范围。同时对产品变质率的变化率θ和需求量的变化率b进行了敏感性分析,提出在时间折扣契约的基础上,零售商通过加强库存管理也可以有效延长供应链的最优订货周期。     

具有激励机制的VMI系统Stackelberg博弈

一般供应商管理库存(VMI)模型没有考虑激励机制问题,而订货商的激励政策对供应商管理库存的成本分担有很大影响。考虑订货商对管理库存的供应商采取一定的激励政策,建立了一个生产型供应商和一个销售型订货商构成的二级供应链VMI系统的Stackelberg博弈模型。通过博弈最优解、算例和主要参数的灵敏度分析,表明:激励机制对供应商的努力程度和双方利润有较大影响,激励政策与双方库存成本的分担有密切关系。     

供应链上游段VMI模式的共赢条件

选取上游层面VMI模式各参与者为研究对象.考虑实施上游层面VMI模式后,订货(配送)主动权的转移导致订货(配送)策略的不同,以及制造商对各零部件需求速率的不同导致其对各零部件的订货周期也不一致的情况.通过建立数学模型,对实施上游层面VMI模式前后各企业的经济效益进行比较,探讨实施VMI且制造商销售价格不变时,各供应商是否存在合理的销售价格涨幅区间,该区间的价格既能弥补供应商因管理制造商零部件库存多消耗的成本,也能使各制造商和供应商的经济效益都有所提高,实现共赢,为各企业更加长久的合作提供理论依据.     

变库存费且考虑残值的变质性物品最优模型研究

经典的EOQ模型通常假定库存费是不变的,在本文中,我们考虑库存费是可变的．在需求率线性依赖于库存水平的情况下,完善了这个变库存费的EOQ模型．本模型研究物品变质后有残值且经过处理后仍可销售,理论上证明了模型具有唯一的整体最优解,揭示了变库存费对库存系统最优订货策略的影响．     

多供应商、多销售商的两级供应链库存模型研究

研究多个供应商、多个销售商组成的两级供应链的库存系统,在具有价格弹性的市场需求、允许供应商和销售商产生缺货的条件下,针对有无价格折扣的两种情况,分别建立了供应商、销售商各自的库存模型;结合满足供应商和销售商Pareto有效性,建立了含价格折扣的供应链系统整体盈利最大的库存模型.     

Coordinating orders in supply chains through price discounts

In this paper, we examine the issue of order coordination between a supplier and multiple retailers in a decentralized multi-echelon inventory/distribution system where the supplier provides a product to multiple retailers who experience static demand and standard inventory costs. Specifically, we propose and analyze a new policy where a manufacturer, who outsources production to an Original Equipment Manufacturer, offers a price discount to retailers when they coordinate the timing of their orders with the manufacturer's order cycle. We show that our proposed policy can lead to more efficient supply chains under certain conditions, and present a straightforward method for finding the manufacturer's optimal price discount in this decentralized supply chain. A numerical experiment illustrates the managerial implications of our model as well as conditions when a manufacturer should consider adopting such a policy.     

Ordering Cost Depletion in Inventory Policy with Imperfect Products and Backorder Rebate

This study presents an inventory model for imperfect products with depletion in ordering costs and constant lead time where the price discount in the backorder is permitted. The imperfect products are refused or modified or if they reached to the customer, returned and thus some extra costs are experienced. Lately some of the researchers explicitly present on the significant association between size of lot and quality imperfection. In practical situations, the unsatisfied demands increase the period of lead time and decrease the backorders. To control customers' problems and losses, the supplier provides a price discount in backorders during shortages. Also, an order’s policies may result in including some imperfect products in arrival lots. A discount on price may be offered by the supplier on the out-of-stock products to manage the backorder problems. The study aims to develop a model with imperfect products by permitting the price discount in backorders, and the cost of ordering is considered a decision variable. First, it is assumed that the demand for lead time is followed by a normal distribution and then stops it and assumed that the first two moments of demand for lead time are known. Further, the minimax distribution method is used to solve this model, and a separate algorithm is designed. In this study, two models are discussed with and without a normally distributed rate of demand. The current study verified with the help of some numerical examples over various model parameters.     

Optimal stocking strategies for inventory mechanism with a stochastic short-term price discount and partial backordering

Price discount is an important research topic in the field of inventory management. The existing research on this topic mainly considers fixed price discount, but ignores the situation in which stochastic short-term price discount may be involved. In this paper, we study an inventory problem considering stochastic short-term price discount and partial backordering. To address this problem, we propose an optimal replenishment and stocking model to maximise the retailers' profit. After that, a cost–benefit analysis-based heuristic method for solving the developed model is presented by considering two scenarios depending on whether a replenishment point belongs to a discount period or not. Furthermore, an algorithm is provided to elicit an optimal ordering policy from multiple solutions derived from the given heuristic solution method. Finally, a real case is offered to demonstrate the application of the proposed model, followed by a sensitivity analysis. The results indicate that a retailer can identify the optimal replenishment policy with the aim of achieving maximal profit in situations where stochastic short-term price discount and partial backordering are considered for certain inventory problems at hand. In addition, sensitivity analysis illustrates a fact that different values of the introduced parameters may influence the optimal replenishment policy.     

Dynamic pricing for multiple class deterministic demand fulfillment

We consider how a firm should allocate inventory to multiple customer classes that differ based on the price they pay and their willingness to incur delay in fulfillment of their demand. The problem is set in a deterministic demand, economic-order-quantity-like environment with holding, backorder, lost demand and setup costs. The firm either fulfills demand or offers a price discount to induce the demand to wait for fulfillment from the next reorder. We determine the optimal policy and discuss how changes in various parameters affect profitability, customer service, and operational measures such as order frequency and base stock levels. We compare the results to a policy that only rations inventory without dynamic discounting and to a policy that only provides discounts. Through the comparison, we observe that dynamic pricing can be seen as a combination of a pricing mechanism which determines demand and an allocation mechanism that differentiates between customer classes, serving each ones needs. We show that if lower-value customers are distinguished by accepting reduced service, it is possible that both high and low-value customer classes see better levels of service under the optimal policy than under a discounting only policy. In addition we demonstrate the applicability of the results to a stochastic version of the problem.     

短生命周期产品的延期交货和价格折扣模型

用斜坡型函数来描述短生命周期产品需求变化特征,用持有成本不断增加表示短生命周期产品无形变质所带来的损失,研究在允许缺货情况下,如何设置合理价格折扣来控制订单的流失,确定各周期的最佳延迟供货量、最优价格折扣、最优订货时间和订货量,从而实现企业总成本的最优。给出了一种迭代逼近的方法来寻求在有限时域内的最优订购策略,通过数值分析验证了该模型的有效性和可操作性,对相应的参数做出了灵敏度分析。该模型能够确定出企业最佳的价格折扣以挽留住更多的顾客,使其总利润达到最优。     

弹性需求下一类国际供应链的最优价格契约

研究了在最终市场需求具有价格弹性的情况下,由单一制造商、单一零售商组成的国际供应链的最优价格折扣契约。首先建立了零售商和制造商在无折扣、有折扣时的利润模型：然后提出了求解最优价格折扣的算法;最后通过算例仿真,求出了在不同汇率下的最优价格折扣,对问题进行了实证研究。     

Bullwhip effect and complexity analysis in a multi-channel supply chain considering price game with discount sensitivity

This paper constructs a multi-channel supply chain that includes a manufacturer, a dual-channel retailer and an online retailer. The dual-channel retailer has a traditional channel and an online channel, while the manufacturer cooperates with the retailers and opens a direct channel simultaneously. The horizontal and historical price discount sensitivities are taken into account to establish the price-sensitive demand functions. A price game model with the heterogeneous expectations is proposed and analysed with the methods of the stability domain, the bifurcation diagram and the maximum Lyapunov exponent. The complexity and bullwhip effect of each channel are investigated with respect to the price adjustment speed and historical price discount sensitivity. The results show that a moderate or low price discount sensitivity keeps the system stable and a high price discount sensitivity brings the system into the twofold cycle state or chaotic state. It is interesting that if both online channels increase the adjustment speeds with similar strategy the system will enter chaos through the Neimark–Sacker bifurcation. The bullwhip effect is affected by the price adjustment speed and the price discount sensitivity, especially in the double-period or chaotic state, where the bullwhip of the overall supply chain is increased significantly. The results show that controlling price discount sensitivity is useful for supply chain node companies.     

DISCOUNTING DECISIONS IN A SUPPLIER-BUYER RELATIONSHIP WITH A LINEAR BUYER'S DEMAND

In this paper, we analyze discounting decisions for a supplier with a group of homogeneous customers. We focus on two aspects: the gaming nature of the discount problem and the demand consideration in the process. We use a general quantity discount schedule and start with the Stackelberg equilibrium of the problem. It is shown that, for the seller to gain from quantity discount, he has to set up his quantity discount schedule such that the buyer will order more than his EOQ. Both the seller and the buyer can gain significantly from quantity discount. The incentive for discount is twofold: reducing inventory related cost and attracting more demand from the customers. In addition, quantity discount schedule can be very efficient in obtaining the maximum gain the seller and the buyer can possibly obtain together.     

Analyzing the effects of inventory cost setting rules in a disassembly and recovery environment

In this study we consider a disassembly and recovery facility receiving end-of-life products and facing demand for a specific part that is disassembled from the product and then recovered. The disassembly and recovery operations can be either performed before hand, or upon customer arrival. In the latter case, a discount on the selling price is applied to compensate the customer for waiting for the completion of the disassembly and recovery operations. One of the difficulties faced in planning for such a system is the determination of the opportunity cost associated with carrying recovered parts inventory. The difficulty arises in seeking the value added to the part given the costs incurred for maintaining the product return, disassembly and recovery costs and revenue earned from the hulk, that is the remaining product after the disassembly of the part. The main objective of the study is to investigate the effect of different rules to determine this opportunity cost on the performance of the system. Six rules are considered in the study. The performance of the rules is assessed by a computational study under an approximate inventory control policy.