Asymmetric Competition in B2B Spot Markets

We model strategic behavior of two types of suppliers in B2B spot markets: a supplier that has forward contracts and uses the spot market only for inventory liquidation, and a supplier that uses the spot market as its sole selling channel. We find that when the spot market demand is small, the supplier that has forward contracts has a higher incentive to invest in expanding the spot market. When the spot market demand exceeds a threshold size, this situation is reversed, and the supplier with no contracts benefits more from making the spot market more prevalent. We show that a supplier with forward contracts benefits from the existence of the spot market more than a supplier with no contracts and that this result holds with both negative and positive correlation between spot market demand and contracted demand. We find that suppliers producing only for the spot market gain from working in industries where contracted demand and spot market demand are positively correlated, whereas suppliers that have forward contracts benefit from working in industries with a negative correlation between demands, since it allows them to better manage risk. In addition, both total industry supply and spot market supply are higher in industries where demands are negatively correlated.     

Flexible Backup Supply and the Management of Lead‐Time Uncertainty

We consider replenishment decisions for a constant rate demand environment from a supplier with uncertain lead times. We study the potential use of a flexible backup supplier as an emergency response to accurate lead‐time information arriving at (or close after) the beginning of the demand interval and well after an original order with the stochastic lead‐time supplier has been placed. The emergency response decisions involve whether to order and how much from the flexible backup supplier, with the objective of minimizing the cost of meeting demand. We derive the optimal emergency‐response policy and clearly outline its implications on the optimized safety lead time of the original order placement and on the cost of meeting demand. We examine the impact on the use of the flexible backup supplier of factors like the arrival time of accurate lead‐time information and the response lead time of the backup supplier. We further study the potential benefits of the use of the flexible backup supplier in a dual role: as one of the two suppliers in a redundant supply system assigned to originally meet the demand and as an emergency response to later‐arriving lead‐time information. Our numerical studies illustrate the benefits from the use of the flexible backup supplier as an emergency response, but for reasonable purchase premiums and short lead times of flexible backup supply options, their use in a dual (regular and emergency response) role often leads to improved performance over safety lead‐time single and uncertain lead‐time supplier‐replenishment strategies. The benefits of the backup supply options are accentuated the higher the lead‐time uncertainty of the stochastic lead‐time supplier is.     

The Impact of Forecast Errors on Early Order Commitment in a Supply Chain*

Supply chain partnership involves mutual commitments among participating firms. One example is early order commitment, wherein a retailer commits to purchase a fixed‐order quantity and delivery time from a supplier before the real need takes place. This paper explores the value of practicing early order commitment in the supply chain. We investigate the complex interactions between early order commitment and forecast errors by simulating a supply chain with one capacitated supplier and multiple retailers under demand uncertainty. We found that practicing early order commitment can generate significant savings in the supply chain, but the benefits are only valid within a range of order commitment periods. Different components of forecast errors have different cost implications to the supplier and the retailers. The presence of trend in the demand increases the total supply chain cost, but makes early order commitment more appealing. The more retailers sharing the same supplier, the more valuable for the supply chain to practice early order commitment. Except in cases where little capacity cushion is available, our findings are relatively consistent in the environments where cost structure, number of retailers, capacity utilization, and capacity policy are varied.     

Supply Diversification with Responsive Pricing

We study sourcing and pricing decisions of a firm with correlated suppliers and a price‐dependent demand. With two suppliers, the insight—cost is the order qualifier while reliability is the order winner—derived in the literature for the case of exogenously determined price and independent suppliers, continues to hold when the suppliers' capacities are correlated. Moreover, a firm orders only from one supplier if the effective purchase cost from him, which includes the imputed cost of his unreliability, is lower than the wholesale price charged by his rival. Otherwise, the firm orders from both. Furthermore, the firm's diversification decision does not depend on the correlation between the two suppliers' random capacities. However, its order quantities do depend on the capacity correlation, and, if the firm's objective function is unimodal, the total order quantity decreases as the capacity correlation increases in the sense of the supermodular order. With more than two suppliers, the insight no longer holds. That is, when ordering from two or more suppliers, one is the lowest‐cost supplier and the others are not selected on the basis of their costs. We conclude the paper by developing a solution algorithm for the firm's optimal diversification problem.     

Managing Disruptions in Decentralized Supply Chains with Endogenous Supply Process Reliability

Supply disruptions are all too common in supply chains. To mitigate delivery risk, buyers may either source from multiple suppliers or offer incentives to their preferred supplier to improve its process reliability. These incentives can be either direct (investment subsidy) or indirect (inflated order quantity). In this study, we present a series of models to highlight buyers’ and suppliers’ optimal parameter choices. Our base‐case model has deterministic buyer demand and two possibilities for the supplier yield outcomes: all‐or‐nothing supply or partial disruption. For the all‐or‐nothing model, we show that the buyer prefers to only use the subsidy option, which obviates the need to inflate order quantity. However, in the partial disruption model, both incentives—subsidy and order inflation—may be used at the same time. Although single sourcing provides greater indirect incentive to the selected supplier because that avoids order splitting, we show that the buyer may prefer the diversification strategy under certain circumstances. We also quantify the amount by which the wholesale price needs to be discounted (if at all) to ensure that dual sourcing strategy dominates sole sourcing. Finally, we extend the model to the case of stochastic demand. Structural properties of ordering/subsidy decisions are derived for the all‐or‐nothing model, and in contrast to the deterministic demand case, we establish that the buyer may increase use of subsidy and order quantity at the same time.     

The Comparison of Two Vertical Outsourcing Structures under Push and Pull Contracts

In a three‐tier supply chain comprising an original equipment manufacturer (OEM), a contract manufacturer (CM), and a supplier, there exist two typical outsourcing structures: control and delegation. Under the control structure, the OEM contracts with the CM and the supplier respectively. Under the delegation structure, the OEM contracts with the CM only and the CM subcontracts with the supplier. We compare the two outsourcing structures under a push contract (whereby orders are placed before demand is realized) and a pull contract (whereby orders are placed after demand is realized). For all combinations of outsourcing structures and contracts, we derive the corresponding equilibrium wholesale prices, order quantities, and capacities. We find that the equilibrium production quantity is higher under control than under delegation for the push contract whereas the reverse holds for the pull contract. Both the OEM and the CM prefer control over delegation under the push contract. However, under the pull contract, the OEM prefers control over delegation whereas the CM and the supplier prefer delegation over control. We also show that for a given outsourcing structure, the OEM prefers the pull contract over the push contract. In extending our settings to a general two‐wholesale‐price (TWP) contract, we find that when wholesale prices are endogenized decision variables, the TWP contract under our setting degenerates to either a push or a pull contract.     

Uniform vs. Retailer‐Specific Pricing: Incentive Alignment to Enhance Supply Chain Efficiency

We consider a supplier selling to multiple retailers using one of two constant wholesale pricing strategies: a uniform wholesale price (UWP) vs. a retailer‐specific wholesale price (RSWP). In line with the prior literature in economics, our initial finding is that as long as retailers are asymmetric, then (a) the supplier and less efficient retailer would prefer the RSWP strategy and (b) the more efficient retailer would prefer the UWP strategy. By examining the total profits of the supply chain under each pricing strategy, we present a new result: the UWP strategy results in a greater degree of supply chain efficiency as compared to the RSWP strategy. The key intuition driving this result is that by charging a UWP, the supplier signals a fair treatment for downstream retailers, which leads to the more efficient retailer being able to reduce market prices and hence capture a larger share of market demand. Noting that the supplier prefers the RSWP scheme as compared to the UWP scheme, we propose a contract which comprises two components: a UWP per unit complemented with a slotting allowance or side payment. The contract is always preferred by the supplier and also leads to greater supply chain efficiency.     

考虑供应风险的多源应急物资采购双层规划模型

自然灾害频繁发生,事故灾难不断涌现,公共卫生事件猝不及防,社会安全风险交织叠加,给人们的生产和生活带来了巨大的风险和不确定性。在突发事件背景下,考虑应急物资供应中的各类风险,激励多源应急物资的稳定供给,受到党和政府高度重视。应急物资供应有哪些风险,如何规避这些风险,针对多种渠道的采购,如何优化采购结构。这些问题是本论文关注的重点。本文以政府、制造型企业、受灾地区民众为决策主体的三级供应链为基础,构建了上层以整个供应链系统收益最大化为目标函数、下层以供应风险最小化为目标函数的双层规划模型,对不同情景下物资采购订单的分配进行研究。在此基础上,本文以某市洪涝灾害为例进行分析,证明了模型的可行性,并探究了供应风险变化对物资采购订单分配、以及整个供应链系统收益的影响,以期为政府应急物资采购决策提供参考性建议。     

基于看跌期权契约的应急物资采购储备模型

应急物资具有峰值需求量大,需求不确定性强,缺货成本高等特点,这使得政府必须在事前进行一定数量的物资储备。然而,由于应急物资需求的发生概率较低,针对食品药品等一类具有保质期限的物资,一旦在保质期限内需求未发生,则会造成大量的浪费与损失,加重政府的财政负担。虽然传统供应链中的回购契约可使政府将剩余物资回售给供应方,能够在一定程度上降低政府成本,但是供应方并没有因承担多余风险而获取到额外收益。基于此,本文设计了一种基于看跌期权契约的应急物资采购储备模型,用于解决保质期风险而引发的损失问题,并分析了实现政企供应链协调的机制,探讨了双方实现共赢协调的具体条件。此外,本文进一步表明与回购契约相比,基于看跌期权契约所建立的采购储备模式能够在降低政府成本的同时,合理地补偿供应方因承担多余风险而造成的损失,更好地保障了供应方的利益,达到了政府和供应方双赢的目的。     

Production quantity allocation for order fulfilment in the supply chain: a neural network based approach

In the current global business environment, it is very important to know how to allocate products from the producer to buyers (or distributors). If products are not appropriately distributed due to absence of an effective allocation policy, the producer and buyers cannot expect to increase customer satisfaction and financial profit. Sometimes some buyers can order more than the actual demand due to inappropriately forecasting customer orders. This is the big obstacle to the effective allocation of products. If the producer can become aware of buyers’ actual demands, it is possible to realise high-level order fulfilment through the effective allocation of products. In this study, new allocation policies are proposed considering buyers’ demands. The back propagation algorithm, one of the learning algorithms in neural network theory, is used to recognise actual demands from the previous buyers’ orders. After excluding surplus demands included in buyers’ demands, products are allocated to buyers according to one of the existing allocation policies depending on the company's decision. In the numerical examples, new allocation policies reducing buyers’ surplus demands outperform previous allocation policies with respect to average amount of backorder.     

供应中断情况下基于备份供应商的应急决策分析

在供应商-制造商二级供应链中,制造商作为领导者,采用一个战略供应商和一个备份供应商。有两种期权执行模式,一种是需求未知情况下提前向备份供应商订货的推式订货模式,另一种是获知需求后再向备份供应商订货的推式与拉式相结合的订货模式。证明了所建模型均为凸规划,并利用Karush-Kuhn-Tucker条件求得备份供应商的能力预定量、战略供应商订货量以及最优利润的表达式,得出了是否采用备份供应商的临界值。研究结果表明：推式模式下战略供应商的订货量较大,推拉结合模式下备份供应商的能力预定量较大,推拉结合模式下制造商的利润较大;随着战略供应商可靠性系数的增大,推式模式下首先放弃备份供应商的使用;当战略供应商的采购成本、备份供应商的期权执行成本和缺货成本较大,且残值以及可靠性系数较小时,推拉结合模式相对于完全推式的效果更加明显。     

基于补偿合约的供应链定价与能力设计的协调问题研究

研究和分析了在需求不确定并且受价格影响的情况下,供应链中制造商与供应商的产品定价与能力设计的协调问题。制造商从供应商处采购用于产品生产的关键零部件,供应链面临的潜在需求服从随机分布,有效需求则受产品定价的影响。当供应商的生产能力出现约束时,制造商可以从外部其他渠道获取关键零部件,但是需要付出一个更高的采购价格。制造商确定产品的销售价格,供应商确定生产能力。分析比较了在集成供应链与独立决策的供应链中的定价与能力计划策略,提出了一种能够有效协调制造商和供应商的决策行为的补偿合约。最后,进行了数值分析,证明补偿合约的有效性。     

Multiperiod Models with Capacities in Competitive Supply Chain

This paper considers a supply chain setting where several capacitated suppliers compete for orders from a single retailer in a multiperiod environment. At each period, the retailer places orders to the suppliers in response to the prices they announce. Each supplier has a fixed capacity. We consider a make‐to‐stock setting where the retailer can carry inventory. The retailer faces exogenous, price‐dependent demand. We study the problem using ideas from fluid models. In particular, we (i) analyze when there are pure equilibrium policies in this setting and characterize the structure of these policies; (ii) consider coordination mechanisms; and (iii) present some preliminary computational results. We also consider a modified model that uses option contracts to coordinate the supply chain.     

产能有限的供应商主导的双渠道分销策略研究

在供应商产能有限的背景下,研究供应商的最优分配策略和双渠道分销的问题。根据期望利润最大化建立供应商渠道分配模型,依据纳什均衡确定供应商的最优定价、最优产能和最优分销策略。结果表明,在双渠道策略的情况下,供应商应该优先满足销售企业的销售量。若供应链的销售量恰好得到满足,供应商应该按最优产能生产。供应商的渠道选择与供应商产能、供应链各节点的盈利能力和生产成本有关。     

Allocating Capacity with Demand Competition: Fixed Factor Allocation*

We consider a supply chain consisting of a supplier and two retailers. The supplier sells a single product to the retailers, who, in turn, retail the product to customers. The supplier has limited production capacity, and the retailers compete for the supplier's capacity and are duopolists engaged in Cournot competition for their customers. When the sum of the retailers' orders exceeds the supplier's capacity, the supplier allocates his capacity according to a preannounced allocation rule. We propose a new capacity allocation rule, fixed factor allocation, which incorporates the ideas of proportional and lexicographic allocations: it prioritizes retailers as in lexicographic allocation, but guarantees only a fixed proportion of the total available capacity to the prioritized retailer. We show that (1) the fixed factor allocation rule incorporates lexicographic and proportional allocations from the perspectives of the supplier and the supply chain; (2) under fixed factor allocation, the supply chain profit is not affected by the allocation factor when it is greater than a threshold; (3) the retailers share the supply chain profit with the supplier depending on the value of the allocation factor; and (4) the fixed factor allocation coordinates the supply chain when the market size is sufficiently large. We also compare fixed factor with proportional and lexicographic allocations, respectively. Furthermore, we demonstrate how the supplier can optimize his capacity level and wholesale price under fixed factor allocation.     

Optimizing Customer Forecasts for Forecast‐Commitment Contracts

We study a “Forecast‐Commitment” contract motivated by a manufacturer's desire to provide good service in the form of delivery commitments in exchange for reasonable forecasts and a purchase commitment from the customer. The customer provides a forecast for a future order and a guarantee to purchase a portion of it. In return, the supplier commits to satisfy some or all of the forecast. The supplier pays penalties for shortfalls of the commitment quantity from the forecast, and for shortfalls of the delivered quantity from the customer's final order (not exceeding the commitment quantity). These penalties allow differential service among customers. In Durango‐Cohen and Yano (2006), we analyzed the supplier's problem for a given customer forecast. In this paper, we analyze the customer's problem under symmetric information, both when the customer is honest and when he strategically orders more than his demand when doing so is advantageous. We show that the customer gains little from lying, so the supplier can use his control over the contract parameters to encourage honesty. When the customer is honest, the contract achieves (near‐)coordination of the supply chain in a great majority of instances, and thus provides both excellent performance and flexibility in structuring contracts.     

The Impact of Information Sharing and Advance Order Information on a Supply Chain with Balanced Ordering

This paper considers a supply chain with one supplier and multiple retailers that face exogenous heterogeneous end‐customer demands, where all parties utilize base‐stock policies. Each retailer is restricted to order once in every order cycle and their orders are replenished in a balanced manner within the cycle. Our study investigates the impact of information sharing and advance order information (AOI) on the supply chain. We find that the supplier benefits from the two mechanisms via two important factors, the information about observed end‐customer demands and the decision on re‐establishing the replenishment sequence. We derive the supplier's optimal sequence for stochastically comparable end‐customer demands with AOI and propose a sequencing rule for the setting with information sharing. Our numerical study examines the cost impacts of two proposed mechanisms on the entire supply chain.     

Channel Strategies and Stocking Policies in Uncapacitated and Capacitated Supply Chains*

A supply chain consisting of a single supplier distributing two independent products through multiple retailers is analyzed in this paper. The supplier needs to incentivize its retailers to adopt stocking policies that are mutually advantageous and that result in the optimal level of market coverage. The focus is on determining the optimal stocking policies for retailers and the resulting distribution strategy given that the supplier has either unlimited or limited capacity. The results provide insights on the optimal distribution strategy and stocking policies for the supply chain. In general, the paper shows that it is optimal for the supplier to use an intensive distribution strategy (i.e., the products are stocked by all retailers). Selective or exclusive strategies are optimal only when retailers are risk averse, stocking synergies exist, and there are differences in demand or supply uncertainties across products. The analysis also shows that retailers hold larger stocks of a product which generates higher supplier margins but only when the supplier has unlimited capacity. If the supplier has limited capacity, then their margins have no effect on retailers' stocking decisions. Contrary to conventional wisdom, retailers hold larger stocks of a product that has less demand uncertainty as compared to one that has more demand uncertainty.     

考虑不同碳排放处理模式的动态供应商选择及采购批量问题研究

不同的碳排放处理模式及不确定的市场需求等因素影响下,如何选择供应商并确定采购批量直接影响企业的运营和效益。本文在多时间周期、多产品种类、多供应商及随机需求情形下,同时考虑不同碳排放处理模式,分析动态供应商选择及采购批量等最优决策问题,构建混合整数非线性规划模型。通过设计变异算子和扰动因子来改进粒子群算法,力求在短时间内求解大规模决策问题。针对不同规模供应商选择及采购批量决策问题,采用精确方法、近似方法和改进粒子群算法求解。数值实验验证了模型及改进粒子群算法的有效性和可行性,分析了碳税、碳交易价格及碳限额对供应链管理的影响,并给出了供应商选择及碳排放处理的决策参考建议。     

Fairness in Selling to the Newsvendor

This paper studies the impact of fairness concerns on supply chain performance (SCP) in the two‐party newsvendor setting. We extend prior fairness analysis to a wide range of demand distributions, and also allow the degree and definition of fairness to assume a broader range of preferences than those in prior literature. Contrary to prior literature, we find that if the retailer's ideal allocation to the supplier is not sufficiently large, regardless of demand variability, a fair‐minded retailer makes no difference to system efficiency when facing a traditional profit‐maximizing supplier. Only when the retailer's ideal allocation to the supplier is above a threshold can the retailer's fairness concern improve the system efficiency for sufficiently high demand uncertainty. In order for the retailer's fairness concern to improve expected profits of both parties compared to the traditional supply chain case (win–win), the demand uncertainty cannot be too low, the retailer is not very averse to disadvantageous inequity, and his ideal allocation to the supplier is within a specific range. If only the supplier is concerned for fairness, the results range from worsening to improving (but not coordinating) the system and a win–win situation is impossible. Finally, when both the supplier and retailer are fair‐minded, SCP is improved unless both parties prefer to allocate small portions of system profit to the other. Again, win–win will be achieved only when the demand uncertainty is sufficiently high, the retailer's ideal allocation is within a certain range, and he is not very averse to disadvantageous inequity.