考虑疫情风险与双重时效性的生鲜品供应中断库存控制策略研究

为解决重大疫情引发的供应中断导致生鲜品库存水平振荡,在市场需求随机变化的情形下,建立一个由供应商、配送中心和零售商组成的三级生鲜供应链库存系统,考虑由疫情引起的三种风险情景,引入系统动力学模型对零售商动态库存系统运营进行仿真分析。研究发现：受疫情风险传导系数和变质率两个序参量影响,供应链库存呈现振荡趋势;通过确定不同供应中断时长下的疫情风险情景提出优化保鲜投入策略、安全库存策略、以及共享库存联合提前转运策略有效降低零售端库存水平振荡并使其呈现渐稳趋势,实现产品在交付过程中的双重时效性,达到供需匹配,缓解疫情风险带来的影响,为相关零售企业提供决策支持。     

CVaR准则下两条供应链的促销努力竞争与链内协调研究

研究两条供应链相互竞争下决策者风险厌恶程度的影响和链内协调问题。针对两条分别由风险中性制造商和风险厌恶零售商组成、进行订货与促销竞争的可替代产品供应链,假定需求随机且依赖于促销努力水平与产品合格率,利用条件风险值(CVaR)方法和博弈理论建立了对应两条供应链均为分散式供应链(DD模式)、均为集中式供应链(II模式)、一条为分散式供应链一条为集中式供应链(DI模式)的EPEC、Nash和MPEC竞争决策模型,给出了三种模式下的竞争均衡决策、以及零售商为风险厌恶者时可实现链内协调的回购加促销补贴契约。进一步分析了零售商风险中性情况。最后的算例验证了模型的合理性和协调契约的有效性。研究表明,零售商越厌恶风险,其订货量越低;产品合格率越高,零售商的促销努力水平越大;供应链协调是供应链竞争下的占优策略。     

竞争环境下多个损失规避零售商的供应链回购契约

研究由单个风险中性的供应商与多个竞争的损失厌恶零售商组成的两阶段供应链,在回购契约中考察竞争和零售商的损失厌恶态度对其最优订购决策和整个供应链协调性的影响.应用博弈论的方法,证明了该供应链博弈存在唯一的纯策略Nash均衡,而且竞争使得零售商的总订购量上升,而损失规避使得总订购量下降.竞争的存在削弱了损失厌恶效应对整个供应链协调性的影响.研究还发现,零售商的最优订购量随供应商的批发价增大而增大,随回购价格的增大而减少,并且在一定条件下回购契约可以使得供应链达到协调.     

考虑零售商库存能力约束的供应链网络均衡模型研究

在考虑零售商库存能力约束情形下,研究了多个竞争的零售商与供应商组成的供应链网络均衡问题.通过对供应链各层级的供应商、零售商、消费市场最优性条件的分析,利用变分不等式构建了供应链网络均衡模型.最后,运用投影收缩算法对均衡模型进行求解,并仿真分析了零售商库存能力约束对网络成员及整个供应链网络的影响.     

基于风险态度的两级供应链设计与优化

决策者的风险态度将对供应链系统性能产生重要影响。供应链中考虑了供应商的产品价格、风险等级、供应能力和零售商需求为不确定性风险因素,研究了基于决策者风险态度的两级供应链设计与优化问题。建立了基于可信性测度的模糊机会约束规划模型,分析了风险态度的变化对供应链系统结构和目标的影响。     

供应中断风险承担策略下供应链产品质量决策

研究由一个制造商和一个零售商构成的二级供应链,引入供应中断风险并通过斯塔克伯格博弈对比分析制造商风险承担策略、零售商风险承担策略以及风险-收益协调策略三种不同的风险承担策略下供应链的产品质量决策及其影响.结果显示:当供应中断损失率较低时,无论采取哪种风险承担策略,供应中断风险损失率上升都会降低制造商的产品质量,影响零售商的销售价格以及市场需求,降低制造商和零售商的利润;制造商风险承担策略会降低产品质量、产品价格、市场需求以及供应链成员绩效;而零售商承担风险策略则有利于提高产品质量和供应链成员绩效;采取风险-收益协调策略能提高产品质量以及供应链成员利润,其程度取决于制造商和零售商的议价能力,制造商的议价能力越强,其产品质量和利润就越高,零售商的利润就越低.比较而言,风险-收益协调策略是最优的.     

竞争环境下基于双重微分博弈的低碳供应链动态优化与协调

在节能减排背景下考虑制造商低碳生产、零售商宣传竞争的情形,将碳减排量以及商誉作为状态变量,借助微分博弈研究供应链动态优化与协调问题。针对双重边际化效应,通过引入成本共担契约对供应链进行协调。研究表明,引入契约后零售商处的低碳宣传努力水平提高、低碳商誉提升、需求量增加,供应链利润基本达到集中决策水平;随着竞争程度的增加,市场需求量提高,制造商利润增加,供应链整体利润提高,启发供应链企业在决策过程中创造良性竞争环境、形成良性竞争机制。     

随机需求下供应商管理库存的供应链模型

以一个供应商和一个零售商的两阶段供应链为背景,利用报童模型给出了供应商管理库存(VMI)的供应链模型,在需求服从均匀分布的条件下得出解析解,并与传统的零售商管理库存(RMI)系统作了比较,分析了这两种情况下批发价和订货量的变化.数值结果表明VMI导致了批发价的缩减,但提高了订货量,VMI减轻了双重边际效应,系统利润多于传统的RMI系统.     

基于条件风险值准则的供应链回购契约协调策略

研究了由具有风险偏好的零售商和风险中性的供应商组成的两级供应链回购契约协调问题.针对具有风险偏好的零售商,考虑了风险中性、风险厌恶和风险喜好三种态度,建立了由风险厌恶程度和悲观系数两个参数描述的基于条件风险值(CVaR)的集成目标决策函数.推导了不同风险偏好态度下的零售商最优订货决策,分析了不同风险偏好参数下的零售商订货决策变化情况.给出了能够完全协调风险偏好零售商和风险中性供应商的供应链回购契约协调机制.最后,进行了数值计算,验证了设计的供应链回购契约协调策略的有效性.结果表明,在给出的回购契约协调机制下,考虑风险偏好情况下的零售商最优订货决策能够保证整个供应链系统实现最优绩效,而供应链成员期望利润却随不同的风险偏好参数而不同.     

需求可变性降低对均值CVaR约束销售努力决策库存系统的影响

本文运用Levy提出的变换研究需求可变性降低对风险偏好零售商的库存决策、销售努力决策和期望效用的影响,用均值CVaR刻画零售商的风险偏好特性,它包括风险厌恶、风险追求,也具有损失规避的特性。首先,运用该变换定量刻画需求可变性的降低,证明该变换蕴含经典随机占优中的割准则序和二阶随机占优等。其次,给出系统的最优订货量、最优期望效用和最优销售努力水平,得到它们关于风险偏好系数的单调性,并给出降低需求可变性对期望效用的影响。第三,针对风险中性、风险厌恶(最大化CVaR)和风险追求(最小化CVaR)这三种特殊情况得到相应的结果,并给出企业在库存决策和促销决策的管理启示。最后,通过数值例子验证了得到的研究结果并给出相应的管理启示。     

A fuzzy newsvendor approach to supply chain coordination

In the absence of a clear command and control structure, a key challenge in supply chain management is the coordination and alignment of supply chain members who pursue divergent and often conflicting goals. The newsvendor model is typically used as a framework to quantify the cost of misalignment and to assess the impact of various coordination initiatives. The application of the newsvendor framework, however, requires the specification of some probability distribution for the sources of uncertainty, and in particular, for the market demand. The specification of an adequate demand distribution becomes difficult in the absence of statistical data. We therefore consider a fuzzy approach to the newsvendor problem. We use several fuzzy parameters in the model for the demand, the wholesale price, and the market sales price. We solve the fuzzy newsvendor problem to study three coordination policies: quantity discounts, profit sharing, and buyback. For each coordination policy, the optimal order quantity of the retailer is computed. The possible profits of the members in the supply chain are calculated with minimum sharing of private information. We further extend the fuzzy newsvendor model to a setting with a single manufacturer and multiple retailers under the assumption of ample capacity for the manufacturer. Detailed numerical examples are also provided.     

基于质押贷款下的库存管理问题的研究

库存决策不仅受需求、运输费用、储存费用的影响,而且企业本身的资金状况也会限制企业实施库存管理.以报童模型为原型,讨论了企业存在道德风险的情况下,以仓单质押方式融资的企业的库存管理决策.假设企业是风险中性的并且商品的储存费用不小于商品的处理价格.研究发现,只有质押库存比较小的企业才会用掉所有的贷款限额.并且随着贷款价值比的增加,企业有可能保留部分资金,而使用贷款增加库存.     

Stability and monotonicity in newsvendor situations

This study considers a supply chain that consists of n retailers, each of them facing a newsvendor problem, and a supplier. Groups of retailers might increase their expected joint profit by joint ordering and inventory centralization. However, we assume that the retailers impose some level of stock that should be dedicated to them. In this situation, we show that the associated cooperative game has a non-empty core. Afterwards, we concentrate on a dynamic situation, where several model cost parameters and the retailers’ dedicated stock levels can change. We investigate how the profit division might be affected by these changes. We focus on four monotonicity properties. We identify several classes of games with retailers, where some of the monotonicity properties hold. Moreover, we show that pairs of cooperative games associated with newsvendor situations do not necessarily satisfy these properties in general, when changes in dedicated stock levels are in concern.     

存货质押融资模式下的供应链协调

针对供应商、零售商和银行组成的供应链金融系统,研究了存货质押融资模式下的供应链协调。零售商作为中小企业,资金有限,需要向银行申请贷款,然而零售商信用较低难以获得融资。供应商作为供应链的核心企业,采用含有回购价格和回购比例的回购契约为零售商提供担保,使得零售商融资得以实现。分析了不确定需求下供应链金融系统,供应链以及零售商的最优决策,给出了融资情况下供应链协调的条件,指出了在供应链协调情况下批发价格和回购策略对供应链收益分配的影响,说明了回购的作用:一方面使零售商易于获得银行融资,另一方面使供应链协调得以实现,指出了质押率、贷款利率和零售商自有资金等参数对最优决策的影响。数值算例验证了理论分析结果。     

Loss-averse newsvendor problem with supply risk

Modeling the manufacturer as a newsvendor, in this paper we study the ordering decisions of a loss-averse newsvendor with supply and demand uncertainties. Using the stylized newsvendor models, we analyse several key issues, including the effect of the newsvendor’s loss aversion, the effect of demand uncertainty, and the effect of supply uncertainty on the decision maker’s optimal decision under the procurement model, in which the decision maker only pays for the actual quantity received. Through our analysis, we find the following facts: the optimal order quantity decreases with respect to the degree of loss-aversion; the supply uncertainty induces the decision maker to order more than that in a deterministic environment; a stochastically larger demand always results in a larger order quantity and a larger expected utility; the optimal expected utility decreases in the demand volatility while the optimal order quantity may increase or decrease. Moreover, with numerical experiments, we demonstrate that the supply risk negatively affects the utility more than the demand risk does.     

基于M-CVaR的供应链收益共享契约协调研究

基于收益共享契约能有效改善供应链运作效率且实践中不仅存在风险中性、厌恶型,还存在风险喜好型供应链成员。运用均值-条件风险价值统一度量决策者的风险喜好、中性及厌恶水平,并据此研究考虑决策者风险偏好水平的供应链收益共享契约协调问题。首先建立零售商及供应链整体的均值-条件风险价值模型;然后研究考虑决策者风险偏好水平的供应链收益共享契约协调问题;最后讨论供应链成员的风险偏好水平对最优订购量及最优批发价格的影响,并通过数值算例进行验证。结果表明产品的最优批发价格随着零售商悲观系数的增大而减小,随着供应商悲观系数的增大而增大,而最优订购量随着零售商悲观系数的增大而减小,亦随着供应商悲观系数的增大而减小。因此,设计供应链收益共享契约时应考虑成员的风险偏好水平。     

The risk-averse newsvendor problem with random capacity

We study the effect of capacity uncertainty on the inventory decisions of a risk-averse newsvendor. We consider two well-known risk criteria, namely Value-at-Risk (VaR) included as a constraint and Conditional Value-at-Risk (CVaR). For the risk-neutral newsvendor, we find that the optimal order quantity is not affected by the capacity uncertainty. However, this result does not hold for the risk-averse newsvendor problem. Specifically, we find that capacity uncertainty decreases the order quantity under the CVaR criterion. Under the VaR constraint, capacity uncertainty leads to an order decrease for low confidence levels, but to an order increase for high confidence levels. This implies that the risk criterion should be carefully selected as it has an important effect on inventory decisions. This is shown for the newsvendor problem, but is also likely to hold for other inventory control problems that future research can address.     

Option contracts: a solution for overloading problems in the delivery service supply chain

Owing to the limited service capacity of express delivery providers, most online retailers have to reject many orders during hot selling seasons. In this paper, we consider an express delivery service supply chain consisting of an express delivery provider and an online retailer whereby the selling season includes both regular periods and online sales periods. Utilizing a modified newsvendor model, we derive the express delivery provider’s optimal capacity decision and find that the overloading problem cannot be avoided because delivery service cannot be inventoried. To solve such a problem, we introduce an option contract to coordinate the supply chain. By allowing the online retailer to book the capacity, the express delivery provider can rent capacity from a third party in advance. Results show this approach can mitigate the problem significantly. We also extend our model to a supply chain consisting of a delivery provider and two retailers.     

基于不同政府补贴策略的供应链绿色努力决策比较研究

研究由单一制造商与单一零售商组成的二级绿色供应链,探讨在同时考虑制造商与零售商绿色努力情况下政府补贴策略对供应链绿色努力与定价决策的影响,比较分析无补贴策略、制造商补贴策略与消费者补贴策略对决策影响的差异性,并进一步考虑零售商的风险规避特征对最优决策的影响。结果表明,政府补贴能够激励制造商与零售商的绿色努力行为,对供应链的绿色发展总是有利的;且制造商补贴策略下的绿色质量水平高于消费者补贴策略,但对供应链利润而言并不是最优的;而在消费者补贴策略下,尽管产品的绿色质量水平不是最优的,但供应链可以获得最高的利润。研究还发现,风险规避特征不会改变参数对最优决策与最优利润的影响趋势,但会降低零售商的绿色努力积极性,导致其利润的下降。