公平偏好下基于回购契约的供应链协调模型

在报童模型的基础上,以一个供应商和一个零售商组成的两级供应链为研究背景,把公平关切引入到回购契约的研究中,并根据Nash讨价还价博弈思想建立公平偏好框架,通过建立效用函数模型,研究了公平关切对回购契约的影响．研究发现,公平关切不会影响回购契约的协调性,公平关切程度也不会影响零售商的最优订购量,进而可以得出,即使供应商在不知道零售商对公平偏好的程度下,依然可以通过制定合适的批发价格和回购价格来做出使自己效用最大化的最优决策．另外,通过灵敏度分析发现,在公平关切时,零售商的最优订购量会随着产品单位生产成本的增加而增加．     

随机需求下供应链协调优化模型

考虑了由一个供应商和多个零售商构成的两级供应链系统,在随机需求下,通过共同补给期进行协调的问题.作为Stackelberg博弈的领导者,供应商给出共同补给期策略,零售商作为跟随者以最优库存策略响应,建立了确定共同补给期和相应价格折扣模型.通过数值实例对该模型进行分析,得出Stackelberg均衡解,达到Pareto最优.     

考虑供应商服务与零售商退货的定价博弈分析

研究由一个供应商和一个零售商组成的二级供应链,由供应商提供产品服务,零售商制定产品零售价,在一个销售周期结束后存在零售商向供应商的退货,退货产生的物流成本由零售商与供应商通过博弈的方式共同分担.基于博弈理论,建立了供应商和零售商以各自利润最大化为目标,以服务水平、零售价和退货为主要影响因素的Nash和Stackelberg博弈.采用数值方法,对这两个博弈进行了求解.得到供应商为零售商分担退货物流成本最优比例、供应商最优服务水平和零售商最优定价策略.研究表明,Nash博弈时的解是唯一的,此时供应商不会分担退货物流成本;Stackelberg博弈时,供应商分担退货物流成本比例依据批发价大小而定.     

品牌专营下供应链价格和批量联合最优决策

假定需求是价格的函数,首先研究了非品牌专营下供应链的最优价格决策和最优批量决策,然后研究了品牌专营下供应商、零售商价格和批量的最优决策.建立了供应商优先决策的Stackelberg博弈模型,通过求解得到了该博弈问题均衡解,即得到了供应商控制的品牌产品最优零售价格和零售商控制的最优订货批量.最后将该模型应用于一个实例中,比较了非品牌专营下和品牌专营下最优决策的不同和供应链利润的不同,品牌专营提高了供应链整体的利润以及供应商自身利润占整个供应链利润的比例.     

供应商联盟动了谁的奶酪?

在两个生产替代产品的供应商和一个零售商组成的供应链中,探索了供应商之间合作而结成供应商联盟以及竞争而不结盟情况下,供应商以及零售商的最优管理决策问题,进一步分析了供应商联盟对于供应链中各方利益的影响.通过比较供应商结盟和供应商不结盟两种情况下的最优决策和利润,得到了一些与传统经验不同的管理启示:供应商联盟并不能保障供应商自身的利益,不能成为对抗强势零售商的手段.具体地说,供应商联盟损害了消费者的利益,损害了供应商自身的利润,损害了供应链整体的利益;相反,供应商联盟可以使得零售商受益.     

考虑市场需求不确定下的供应链协调优化

在市场需求不确定的情况下,考察市场需求依赖销售价格,建立一个由单一供应商和单一零售商组成的二级退货模型,并分别从集中决策和分散决策两方面讨论,证明单纯的退货政策无法实现供应链协调,而通过引入回馈与惩罚机制后则可以实现协调,并求出此时的最优订货量和最优售价.最后,通过数值算例证明以上的结论.     

ARMA（1,1）需求下的信息延迟对供应链最优决策的影响

在假定顾客需求满足ARMA（1,1）过程的前提下,考虑了由一个零售商和一个供应商所组成的两级供应链系统最优订购决策问题.分别建立了需求信息不延迟与延迟这两种情形下零售商和供应商的最优订购决策模型,通过比较得出：当需求呈正相关时,需求信息延迟不仅可以减小牛鞭效应,而且可以降低供应链系统的平均总成本.     

突发事件下不对称信息供应链协调机制研究

针对一个由供应商和一个零售商构成的供应链,在零售商成本为私有信息条件下,假设产品的市场需求为零售价格的指数函数,研究如何协调供应链应对突发事件。首先,给出了对称信息下供应链协调模型;然后,研究了不对称信息下集权式与分权式供应链的协调机制;再次,在突发事件引起零售商成本分布函数扰动情况下,通过引入供应商由于可能需要调整生产计划而产生的偏差成本,研究了供应链的最优应对策略。 研究表明,供应链的最优生产计划、最优批发价格和最优零售价格均具有一定的鲁棒性,当突发事件造成零售商期望成本在一定范围内发生扰动时,三者可以保持不变,当零售商期望成本扰动超过一定范围内时,则需要对之加以调整,才能有效应对突发事件。最后,通过数值仿真验证了相关结论。     

关于信用期内含缺陷产品EOQ模型

考虑到在实际中供应链上游供应商提供给下游零售商的信用支付期通常为一个订货周期,建立了缺陷率服从一定分布的缺陷产品在信用支付策略下的最优订货批量模型.模型中允许缺货发生并且以最大期望利润为目标函数,通过分析得到模型最优解.最后给出仿真实验,并且分析了模型参数变化对最优解的影响.     

基于商业信用和回购契约的供应链最优化策略研究

本文考虑由单一供应商和零售商组成的供应链系统,当供应商为零售商提供回购契约,同时零售商又为下游顾客提供商业信用契约时,供应商如何设计回购契约来有效协调整个供应链,以及零售商又如何借助回购和商业信用契约来做出自身最优订货策略问题,并建立了相应的决策模型。通过模型分析,给出了供应商和零售商在四种情形下的最优契约设计参数,以及零售商的最优订货决策。研究发现,当满足一定的参数范围时,供应链中两主体同时采用协调契约能够更加有效地增加整个供应链中的订货量和利润,为各主体创造更多新的价值。最后,本文结合数值例子,分析了模型参数变化对最优订货策略和各主体利润的影响。     

A two-warehouse partial backlogging inventory model for deteriorating items with permissible delay in payment under inflation

In the business transactions, the supplier usually offers a permissible delay in payment to his retailer to attract more sales. In addition, a permissible delay in payment may be applied as an alternative to price discount. Based on the above phenomena, we incorporate a permissible delay in payment into the model of Yang [1] and develop a two-warehouse partial backlogging inventory model for deteriorating items with permissible delay in payment under inflation. The objective of this study is to derive the retailer’s optimal replenishment policy that maximizes the net present value of the profit per unit time. The necessary and sufficient conditions for an optimal solution are characterized. An algorithm is developed to find the optimal solution. Finally, numerical examples are provided to illustrate the proposed model. Sensitivity analysis is made and some managerial implications are presented.     

Economic order quantity under conditionally permissible delay in payments

Within the economic order quantity (EOQ) framework, the main purpose of this paper is to investigate the retailer’s optimal replenishment policy under permissible delay in payments. All previously published articles dealing with optimal order quantity with permissible delay in payments assumed that the supplier only offers the retailer fully permissible delay in payments if the retailer ordered a sufficient quantity. Otherwise, permissible delay in payments would not be permitted. However, in this paper, we want to extend this extreme case by assuming that the supplier would offer the retailer partially permissible delay in payments when the order quantity is smaller than a predetermined quantity. Under this condition, we model the retailer’s inventory system as a cost minimization problem to determine the retailer’s optimal inventory cycle time and optimal order quantity. Three theorems are established to describe the optimal replenishment policy for the retailer. Some previously published results of other researchers can be deduced as special cases. Finally, numerical examples are given to illustrate all these theorems and to draw managerial insights.     

两货栈及延期支付和现金折扣情形下变质产品的最优订货策略

已有的两货栈库存模型通常不考虑将延期支付和现金折扣相结合的情形,但实际上,供应商在给予销售商延期支付政策的同时,也会实施现金折扣策略以激励销售商尽快付款,加快资金周转,减少坏账损失。为此,本文建立了延期支付和现金折扣情形下变质产品的两货栈库存模型,并对模型的最优解进行理论分析,给出了最优解的求解步骤。最后通过数值算例对模型的可行性进行了验证,并分析了模型参数变化对最优订货策略和最优付款时间的影响。     

两货栈及延期支付和现金折扣情形下变质产品的最优订货策略

已有的两货栈库存模型通常不考虑将延期支付和现金折扣相结合的情形,但实际上,供应商在给予销售商延期支付政策的同时,也会实施现金折扣策略以激励销售商尽快付款,加快资金周转,减少坏账损失。为此,本文建立了延期支付和现金折扣情形下变质产品的两货栈库存模型,并对模型的最优解进行理论分析,给出了最优解的求解步骤。最后通过数值算例对模型的可行性进行了验证,并分析了模型参数变化对最优订货策略和最优付款时间的影响。     

An EOQ model for deteriorating items under supplier credits linked to ordering quantity

In the classical inventory economic order quantity (or EOQ) model, it was assumed that the purchaser must pay for the items received immediately. However, in practices, the supplier usually is willing to provide the purchaser a permissible delay of payments if the purchaser orders a large quantity. As a result, in this paper, we establish an EOQ model for deteriorating items, in which the supplier provides a permissible delay to the purchaser if the order quantity is greater than or equal to a predetermined quantity. We then characterize the optimal solution and provide an easy-to-use algorithm to find the optimal order quantity and replenishment time. Finally, several numerical examples are given to illustrate the theoretical results.     

An ordering policy with allowable shortage and permissible delay in payments

It is common business practice to purchase inventory on an open account. Purchased inventory can be considered to be financed in whole or in part with permissible delay in payments. This paper develops a model to determine an optimal ordering policy under conditions of allowable shortage and permissible delay in payment and shows that the total annual variable cost function possesses some kinds of convexities. With those convexities, a theorem is presented to determine the optimal order quantity. Numerical examples are given to illustrate the theorem.     

An inventory model for increasing demand under two levels of trade credit linked to order quantity

During the growth stage of a product life cycle especially for high-tech products, the demand function increases with time. In this paper, we extend the constant demand to a linear non-decreasing demand function of time and incorporate a permissible delay in payment under two levels of trade credit into the model. The supplier offers a permissible delay linked to order quantity, and the retailer also provides a downstream trade credit period to its customers. The objective is to find the optimal replenishment cycle that minimizes the retailer’s annual total relevant cost per unit time. The condition for an optimal solution to the generalized model is presented and some fundamental theoretical results are established. Finally, numerical examples to illustrate the proposed model are provided. Sensitivity analysis is performed and some relevant managerial insights are obtained.     

An ordering policy for deteriorating items with allowable shortage and permissible delay in payment

In many inventory situations, the purchaser is allowed a permissible period to pay back the cost of goods bought without paying any interest. Depending on the length of that payment period, the purchaser can earn interest on the sales of the inventory. This paper develops a model to determine an optimal ordering policy for deteriorating items under permissible delay of payment and allowable shortage. Different facets of the permissible delays in payment are discussed, and this generalized model exhibits a set of solutions that reduces to an existing model. Results are discussed and demonstrated with an illustrative example.     

On an EPQ model for deteriorating items under permissible delay in payments

This paper derives a production model for the lot-size inventory system with finite production rate, taking into consideration the effect of decay and the condition of permissible delay in payments, in which the restrictive assumption of a permissible delay is relaxed to that at the end of the credit period, the retailer will make a partial payment on total purchasing cost to the supplier and pay off the remaining balance by loan from the bank. At first, this paper shows that there exists a unique optimal cycle time to minimize the total variable cost per unit time. Then, a theorem is developed to determine the optimal ordering policies and bounds for the optimal cycle time are provided to develop an algorithm. Numerical examples reveal that our optimization procedure is very accurate and rapid. Finally, it is shown that the model developed by Huang [1] can be treated as a special case of this paper.     

An economic order quantity model for deteriorating items with partially permissible delay in payments linked to order quantity

To attract more sales suppliers frequently offer a permissible delay in payments if the retailer orders more than or equal to a predetermined quantity W. In this paper, we generalize [Goyal, S.K., 1985. EOQ under conditions of permissible delay in payments. Journal of the Operational Research Society 36, 335–338] economic order quantity (EOQ) model with permissible delay in payment to reflect the following real-world situations: (1) the retailer’s selling price per unit is significantly higher than unit purchase price, (2) the interest rate charged by a bank is not necessarily higher than the retailer’s investment return rate, (3) many items such as fruits and vegetables deteriorate continuously, and (4) the supplier may offer a partial permissible delay in payments even if the order quantity is less than W. We then establish the proper mathematical model, and derive several theoretical results to determine the optimal solution under various situations and use two approaches to solve this complex inventory problem. Finally, a numerical example is given to illustrate the theoretical results.