Economic analysis of demand uncertainty and delayed information sharing in a third-party managed supply chain

Designers and retailers in consumer products industry are faced with high demand volatility and potential loss of profit from design piracy. Many retailers rely on third-party supply chain managers (SCMs) to manage global supply chains. A SCM starts raw materials procurement and production process based on expected demand and takes financial risks associated with demand uncertainty. But a retailer often delays sharing product design information with SCM forcing it to expedite production and distribution processes incurring additional financial penalties. To analyse economic impact of delayed information sharing under uncertain demand, we develop a mathematical model. Our model indicates that higher demand volatility lessens the effect of penalty associated with delayed information sharing for retailers. The model also shows that for a given demand volatility, per-unit premium increases asymptotically for a retailer compared to marginal production cost increase for SCM. Such findings are not intuitive for SCMs or retailers.     

Production and Sales Planning in Capacitated New Product Introductions

How should a firm with limited capacity introduce a new product? Should it introduce the product as soon as possible or delay introduction to build up inventory? How do the product and market characteristics affect the firm's decisions? To answer such questions, we analyze new product introductions under capacity restrictions using a two‐period model with diffusion‐type demand. Combining marketing and operations management decisions in a stylized model, we optimize the production and sales plans of the firm for a single product. We identify four different introduction policies and show that when the holding cost is low and the capacity is low to moderate, a (partial) build‐up policy is indeed optimal if consumers are sensitive to delay. Under such a policy, the firm (partially) delays the introduction of its product and incurs short‐term backlog costs to manage its future demand and total costs more effectively. However, as either the holding cost or the capacity increases, or consumer sensitivity to delay decreases, the build‐up policy starts to lose its appeal, and instead, the firm prefers an immediate product introduction. We extend our analysis by studying the optimal capacity decision of the firm and show that capacity shortages may be intentional.     

An Empirical Analysis of the Effect of Supply Chain Disruptions on Long‐Run Stock Price Performance and Equity Risk of the Firm

This paper investigates the long‐term stock price effects and equity risk effects of supply chain disruptions based on a sample of 827 disruption announcements made during 1989–2000. Stock price effects are examined starting one year before through two years after the disruption announcement date. Over this time period the average abnormal stock returns of firms that experienced disruptions is nearly –40%. Much of this underperformance is observed in the year before the announcement, the day of the announcement, and the year after the announcement. Furthermore, the evidence indicates that firms do not quickly recover from the negative effects of disruptions. The equity risk of the firm also increases significantly around the announcement date. The equity risk in the year after the announcement is 13.50% higher when compared to the equity risk in the year before the announcement.     

突发性产出下的供应链协调应对策略

针对突发事件影响制造商产出的情形，研究了收益共享契约协调应对突发产出事件的有效性问题。首先论证了无突发产出事件时收益共享契约协调供应链的有效性，进而分析了突发产出事件对供应链最优生产计划、定价决策、绩效和协调性的影响。然后，建立了突发产出事件下的收益共享契约协调应对模型，并对原收益共享契约和修正后的收益共享契约进行了对比分析。研究表明：当突发产出事件导致产出扰动范围较小时，供应链的最优生产计划、批发价格和零售价格几乎保持不变，仅当产出扰动范围较大时，三者才需要同时调整，此时原供应链的协调性也将被打破，而修正后的收益共享契约具有良好的抗突发性。最后，通过算例进行了验证。     

Demand–Supply Mismatches and Stock Market Performance: A Retailing Perspective

We provide empirical evidence that the volatility of inventory productivity relative to the volatility of demand is a predictor of future stock returns in a sample of publicly listed U.S. retailers over the period 1985–2013. This key performance indicator, entitled demand–supply mismatch (DSM), captures the fact that low variation in inventory productivity relative to variation in demand is indicative of the superior synchronization of demand‐ and supply‐side operations. Applying the Fama and French (1993) three‐factor model augmented with a momentum factor (Carhart 1997), we find that zero‐cost portfolios formed by buying the two lowest and selling the two highest quintiles of DSM stocks yield abnormal stock returns of up to 1.13%. These strong market anomalies related to DSM are observed over the entire sample period and persist after controlling for alternative inventory productivity measures and firm characteristics that are known to predict future stock returns. Further, we reveal that DSM is indicative of lower future earnings and lower sales growth and provide evidence that the observed market inefficiency results from investors’ failure to incorporate all of the information that inventory contains into the pricing of stocks.     

Dynamic Pricing and Inventory Management with Dual Suppliers of Different Lead Times and Disruption Risks

It is common for a firm to make use of multiple suppliers of different delivery lead times, reliabilities, and costs. In this study, we are concerned with the joint pricing and inventory control problem for such a firm that has a quick‐response supplier and a regular supplier that both suffer random disruptions, and faces price‐sensitive random demands. We aim at characterizing the optimal ordering and pricing policies in each period over a planning horizon, and analyzing the impacts of supply source diversification. We show that, when both suppliers are unreliable, the optimal inventory policy in each period is a reorder point policy and the optimal price is decreasing in the starting inventory level in that period. In addition, we show that having supply source diversification or higher supplier reliability increases the firm's optimal profit and lowers the optimal selling price. We also demonstrate that, with the selling price as a decision, a supplier may receive even more orders from the firm after an additional supplier is introduced. For the special case where the quick‐response supplier is perfectly reliable, we further show that the optimal inventory policy is of a base‐stock type and the optimal pricing policy is a list‐price policy with markdowns.     

Durability,Transit Lags,and Optimality of Inventory Management Decisions

Two laboratory experiments on a single‐echelon inventory task show that inventory durability interacts with transit lags to create order volatility that exceeds demand volatility. Thus, inventory durability and transit lags cause managers to deviate from inventory decision optimality. Durability creates a large increase in order volatility because players adjust orders insufficiently to reflect current inventory and backlogs, much as they adjust orders insufficiently to reflect holding and backlog costs in newsvendor studies (e.g., Schweitzer and Cachon 2000). Transit lags exacerbate non‐optimal ordering by interfering with players' ability to correct prior errors. Our results suggest that non‐optimal inventory decisions can be driven by inventory and supply chain characteristics, even in the absence of the coordination and information sharing problems studied by Croson et al. (2005) and Sterman (1989a,b). We also examine the influence of features related to personality. We find little evidence that the interactive effects of durability and transit lags are altered by need for cognition, impulsiveness, or locus of control, suggesting that these features make supply chain management extremely difficult. These results imply that retailers and their upstream partners must consider the characteristics of their product and supply chains when interpreting demand signals received from downstream partners.     

供应链管理模型的分类和研究进展

本文首先在综合近年来供应链管理的国内外研究文献的基础上,从研究对象与方法的界定和研究内容的界定两个层面对供应链管理模型进行了分类。然后,对供应链管理中的几类主要问题:供应链中的库存问题、供应链中的信息流及其价值问题、供应链协调与契约等问题的外部环境进行了简要分析,对其研究进展进行了综述。最后,展望了供应链管理模型未来的研究方向与热点。     

Centralization versus decentralization: Risk pooling,risk diversification,and supply chain disruptions

We investigate optimal system design in a multi-location system in which supply is subject to disruptions. We examine the expected costs and cost variances of the system in both a centralized and a decentralized inventory system. We show that, when demand is deterministic and supply may be disrupted, using a decentralized inventory design reduces cost variance through the risk diversification effect, and therefore a decentralized inventory system is optimal. This is in contrast to the classical result that when supply is deterministic and demand is stochastic, centralization is optimal due to the risk-pooling effect. When both supply may be disrupted and demand is stochastic, we demonstrate that a risk-averse firm should typically choose a decentralized inventory system design.     

多零售商供应链应对突发事件的协调机制研究

本文针对一个供应商和n个Cournot竞争零售商组成的供应链系统,从系统优化和企业管理的角度研究了该供应链系统如何应对突发事件。首先证明稳定条件下的收益共享合约能实现该供应链协调。但突发事件引起的成本和需求的扰动会打破供应链协调,当突发事件导致供应链的市场需求增加而生产成本减少时,供应商必须通过增加生产来应对突发事件;当突发事件导致供应链的市场需求减少而生产成本增加时,供应商必须通过减少生产来应对突发事件;并通过求解突发事件下供应链系统最优利润的Karush-Kuhn-Tucker(KKT)条件,提出了供应链在一体化时应对突发事件的最优策略。进一步证明了改进的收益共享合约可以协调突发事件下分散化决策的供应链系统。最后运用数值实验对模型进行了验证。     

Dynamic Supply Risk Management with Signal‐Based Forecast,Multi‐Sourcing,and Discretionary Selling

We examine the critical role of advance supply signals—such as suppliers’ financial health and production viability—in dynamic supply risk management. The firm operates an inventory system with multiple demand classes and multiple suppliers. The sales are discretionary and the suppliers are susceptible to both systematic and operational risks. We develop a hierarchical Markov model that captures the essential features of advance supply signals, and integrate it with procurement and selling decisions. We characterize the optimal procurement and selling policy, and the strategic relationship between signal‐based forecast, multi‐sourcing, and discretionary selling. We show that higher demand heterogeneity may reduce the value of discretionary selling, and that the mean value‐based forecast may outperform the stationary distribution‐based forecast. This work advances our understanding on when and how to use advance supply signals in dynamic risk management. Future supply risk erodes profitability but enhances the marginal value of current inventory. A signal of future supply shortage raises both base stock and demand rationing levels, thereby boosting the current production and tightening the current sales. Signal‐based dynamic forecast effectively guides the firm's procurement and selling decisions. Its value critically depends on supply volatility and scarcity. Ignoring advance supply signals can result in misleading recommendations and severe losses. Signal‐based dynamic supply forecast should be used when: (a) supply uncertainty is substantial, (b) supply‐demand ratio is moderate, (c) forecast precision is high, and (d) supplier heterogeneity is high.     

供应链网络系统的牛鞭效应时滞因素分析与库存控制策略研究

牛鞭效应的存在严重影响了供应链系统的运作效率,增加了供应链管理的复杂性。本文基于供应链网络库存状态的内部系统动力学机制,构建了供应链网络库存系统的状态转移模型,并引入时滞影响因素,通过供应链网络库存系统的波动状态描述牛鞭效应。在此模型基础上,针对供应链网络系统的牛鞭效应问题,提出了一类新的基于库存波动状态的动态供应链库存控制策略,并运用系统稳定性理论,将该策略的参数优化求解问题转化成线性矩阵不等式的求解问题。最后通过系统仿真深入分析了供应链网络库存系统对库存控制策略参数以及系统时滞因素的敏感性,并验证了该动态库存控制策略可以有效地抑制牛鞭效应。     

Operational Hedging and Diversification under Correlated Supply and Demand Uncertainty

When facing supply uncertainty caused by exogenous factors such as adverse weather conditions, firms diversify their supply sources following the wisdom of “not holding all eggs in one basket.” We study a firm that decides on investment and production levels of two unreliable but substitutable resources. Applying real options thinking, production decisions account for actual supply capabilities, whereas investment decisions are made in advance. To model triangular supply and demand correlations, we adapt the concepts of random capacity and stochastic proportional yield while using concordant ordered random variables. Optimal profit decreases monotonically in supply correlation and increases monotonically in supply–demand correlation. Optimal resource selection, however, depends on the trivariate interplay of supply and demand and responds non‐monotonically to changing correlations. Moreover, supply hedges (i.e., excess capacity at alternative sources) can be optimal even if supply resources are perfectly positively correlated. To accommodate changing degrees of correlation, the firm adjusts the lower margin capacities under random capacity; but under stochastic proportional production capability, it uses either low‐ or high‐margin capacities to create tailored “scale hedges” (i.e., excess capacity at one source which can partially substitute for diversification).     

Dynamic Pricing and Inventory Management with Regular and Expedited Supplies

We consider a periodic‐review inventory system with regular and expedited supply modes. The expedited supply is faster than the regular supply but incurs a higher cost. Demand for the product in each period is random and sensitive to its selling price. The firm determines its order quantity from each supply in each period as well as its selling price to maximize the expected total discounted profit over a finite or an infinite planning horizon. We show that, in each period if it is optimal to order from both supplies, the optimal inventory policy is determined by two state‐independent thresholds, one for each supply mode, and a list price is set for the product; if only the regular supply is used, the optimal policy is a state‐dependent base‐stock policy, that is, the optimal base‐stock level depends on the starting inventory level, and the optimal selling price is a markdown price that decreases with the starting inventory level. We further study the operational impact of such supply diversification and show that it increases the firm's expected profit, reduces the optimal safety‐stock levels, and lowers the optimal selling price. Thus that diversification is beneficial to both the firm and its customers. Building upon these results, we conduct a numerical study to assess and compare the respective benefit of dynamic pricing and supply diversification.     

Do Shareholders Really Prefer Their Executives to Maximize the Equity Value? A Newsvendor Case*

In this article, we study how the operational decisions of a firm manager depend on her own incentives, the capital structure, and financial decisions in the context of the newsvendor framework. We establish a relationship between the firm’s cost of raising funds and the riskiness of the inventory decisions of the manager. We consider four types of managers, namely, profit, equity, firm value, and profit‐equity maximizers, and initially assume that they may raise funds to increase the inventory level only by issuing debt. We show that the shareholders are indifferent between the different types of managers when the coefficient of variation (CV) of demand is low. However, this is not the case when the CV of demand is high. Based on the demand and the firm’s specific characteristics such as profitability, leverage, and bankruptcy costs, the shareholders might be better off with the manager whose compensation package is tied to the firm value as opposed to the equity value. We, then, extend our model by allowing the manager to raise the required funds by issuing both debt and equity. For this case we focus on the equity and firm value maximizer managers and show that our earlier results (for the debt only case) still hold subject to the cost of issuing equity. However the benefit of the firm value maximizer manager over the equity maximizer manager for shareholders is considerably less in this case compared to the case where the manager can only issue debt. The Board of Directors can take these factors into consideration when establishing/modifying the right incentive package for the managers. We also incorporate the notion of the asymmetric information to capture its impact on the board of directors’ decision about the managers’ incentive package.     

基于RFID技术的双供应链投资决策研究

本文考虑零售商主导的分别由一个供应商和一个零售商组成的两条竞争型供应链中,当两个供应商都未投资RFID技术、只有一个供应商投资RFID技术以及两个供应商同时投资RFID技术时,考虑供应商成本结构的差异,对比分析供应链的投资决策。由于模型解析解过于复杂,本文通过算例分析,着重考虑产品的替代率、RFID标签价格以及库存可获得率三个因素对供应链成员利润的影响。结果表明两条供应链对RFID技术的投资决策会因成本结构和产品替代率的不同而发生变化,其中在两个供应商生产成本差异较大且产品竞争强度较低时,生产成本较高的供应商更愿意投资RFID技术,而生产成本较低的供应商不愿意投资RFID技术,两个零售商则希望使用RFID技术,所以此时仅会有一条供应链上的成员达成一致,决定投资使用RFID技术。     

时间约束下不对称信息鲜活农产品供应链应对突发事件协调模型

针对一个由供应商和一个零售商构成的鲜活农产品供应链,在考虑损耗和新鲜度的影响下,假设产品的市场需求为零售价格的非线性函数,零售商成本为私有信息,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,研究了在突发事件引起零售商成本分布函数扰动情况下,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。最后,通过数值仿真验证了相关结论。     

物流联合外包下库存管理模式对供应链运作的影响

针对由供应商、第三方物流服务商和零售商组成的供应链,考虑供需双方将物流服务联合外包给第三方物流服务商、共同承担运费的情形,探究供应商管理库存和寄售库存两类库存管理模式的引入对供应链运作及合同设计的影响。分别在传统的零售商管理库存、仅引入寄售库存的零售商管理寄售库存以及同时引入供应商管理库存和寄售库存的供应商管理寄售库存三种模式下,构建了第三方物流服务商主导、供应商和零售商跟随的序贯非合作博弈模型,证明了所有模式下均衡的订购量/寄售量均存在且唯一,并探讨了均衡结果随零售商运费分摊比例、转移支付价格两个关键参数的变化。横向对比三种模式下的均衡结果和集中决策下的最优结果,发现：零售商管理库存模式下的均衡订购量总是低于零售商管理寄售库存模式以及集中决策下的结果,而其他库存管理模式下的订购量并非一定低于集中决策下的结果;不同库存管理模式下,均衡状态下的订购量/寄售量及供应链总的期望收益大小关系取决于供应商和零售商的类边际(毛利)贡献率,从而表明,供应链环境下,上下游成员企业的收益结构、盈利水平等对于库存决策及库存模式的选取有重要影响。此外,在绝大多数情形下,不同库存管理模式下的均衡订购量与集中决...     

Exploring Framing Effects in Inventory Control Decisions: Violations of Procedure Invariance

Recent research on decision framing has shown that (i) there are multiple types of framing effects and (ii) the context of the decision can influence framing effects. This research examines decision framing effects in inventory control contexts by questioning the assumption of procedure invariance, that preference should not be impacted by how options are presented to a supply chain manager making an inventory control decision. Study 1 uses three single‐shot decision experiments to establish that all three types of framing effects identified by Levin et al. ( 1998 ) apply in basic inventory control contexts. Results were consistent with theory in all three cases. Given this evidence that framing effects have potential to impact inventory control decisions, two laboratory experiments in Study 2 utilize multi‐period decision tasks to demonstrate that framing effects can impact performance in a dynamic inventory decision setting similar to practice. One of the experiments in Study 2 was conducted with student subjects, while the other with inventory managers from a large retail firm. Results from both experiments provide evidence that even when initial framing effects on order quantities fade, there can be longer term effects on inventory levels and performance. Furthermore, these effects are robust to education and professional experience. The findings suggest that although a manager might select appropriate inventory control metrics, prudence must be exercised in the presentation of these metrics, and that mere presentation can be used to alleviate known human biases in inventory control decisions.     

A queuing/management consideration on Japanese production systems

A single-stage lot/cell production under a Poisson arrival and exponential service in a batch is considered. The three economic queuing models of push and pull types are presented, an economic comparison of push versus pull types is considered, and a strategic management/design consideration to the lot production is given. First, the total expected operating cost is given for the three queuing models including the Omote-Kanban type similar to VMI. Second, the push versus pull system is discussed from a view of setup time, inventory or operating cost, and it is ascertained that the three types are alternative. Finally, a strategic management basis for economic traffic, leadtime setting is given, and discussed by the introduction of production matrix on 2-stage design.