Supply chain networks with global outsourcing and quick-response production under demand and cost uncertainty

This paper develops a modeling and computational framework for supply chain networks with global outsourcing and quick-response production under demand and cost uncertainty. Our model considers multiple off-shore suppliers, multiple manufacturers, and multiple demand markets. Using variational inequality theory, we formulate the governing equilibrium conditions of the competing decision-makers (the manufacturers) who are faced with two-stage stochastic programming problems but who also have to cooperate with the other decision-makers (the off-shore suppliers). Our theoretical and analytical results shed light on the value of outsourcing from novel real option perspectives. Moreover, our simulation studies reveal important managerial insights regarding how demand and cost uncertainty affects the profits, the risks, as well as the global outsourcing and quick-production decisions of supply chain firms under competition.     

供应中断风险下采购与定价决策分析

供应中断是供应链上的企业可能面临的问题,运用合理的采购策略可以帮助企业有效缓解供应中断风险。本文研究了供应中断下供应商和制造商之间的纵向竞争和两个制造商之间的横向竞争问题。供应商制定批发价,两个制造商采用不同的采购策略进行产量博弈,其中一个制造商采用紧急双源订货策略,另一个采用可靠单源订货策略。论文采用了多阶段博弈模型,分析了制造商之间的合谋与竞争两种行为,求出了供应商和制造商的最优决策,比较了这两种行为对供应商和制造商的影响。通过数值分析,讨论了成本参数和可靠性参数对于最优订货量的影响以及对于采用不同订货策略的制造商期望利润的影响。     

Coordination of supply chains by option contracts: A cooperative game theory approach

Manufacturer–retailer supply chains commonly adopt a wholesale price mechanism. This mechanism, however, has often led manufacturers and retailers to situations of conflicts of interest. For example, due to uncertain market demand, retailers prefer to order flexibly from manufacturers so as to avoid incurring inventory costs and to be able to respond flexibly to market changes. Manufacturers, on the other hand, prefer retailers to place full orders as early as possible so that they can hedge against the risks of over- and under-production. Such conflicts between retailers and manufacturers can result in an inefficient supply chain. Motivated by this problem, we take a cooperative game approach in this paper to consider the coordination issue in a manufacturer–retailer supply chain using option contracts. Using the wholesale price mechanism as a benchmark, we develop an option contract model. Our study demonstrates that, compared with the benchmark based on the wholesale price mechanism, option contracts can coordinate the supply chain and achieve Pareto-improvement. We also discuss scenarios in which option contracts are selected according to individual supply chain members’ risk preferences and negotiating powers.     

Pricing and horizontal information sharing in a supply chain with capacity constraint

This paper aims to explore manufacturers horizontal information sharing strategy under competition. The model framework is based on a two-echelon supply chain composed of one upstream supplier and two downstream manufacturers with asymmetric capacity constraint. Analysis of the model establishes manufacturers’ information sharing strategies under different conditions and shows how supplier’s pricing decision can shape manufacturers’ information sharing incentives.     

Decentralization versus coordination in competing supply chains under retailers’ extended warranties

This paper studies a two-tier duopoly competing supply chain system consisting of two manufacturers and two exclusive retailers. Both manufacturers produce differentiated products and both retailers provide extended warranties for the products they sell. Two types of channel-structure strategy options are considered: a decentralized structure with a wholesale price contract and a coordinated structure with a sophisticated contract. We first derive the equilibrium outcomes under three possible chain-to-chain competition scenarios. Subsequently, we reveal how manufacturers control their retail channels to gain more supply chain system profit under an interactive environment with supply chain competition and retailers’ extended warranties. We find that pure coordinated channel competition and pure decentralized channel competition may both reach equilibrium. Furthermore, the interaction forces of supply chain competition and extended warranty service significantly impact the characteristics of the equilibria. Finally, we analyze the competing supply chain’s coordination contract design by using the example of a two-part tariff contract, and determine the feasible contract parameter range that results in a win-win solution for supply chain members.

     

“Bricks vs. Clicks”: The impact of manufacturer encroachment with a dealer leasing and selling of durable goods

In durable goods markets, many brand name manufacturers, including IBM, HP, Epson, and Lenovo, have adopted dual-channel supply chains to market their products. There is scant literature, however, addressing the product durability and its impact on players’ optimal strategies in a dual-channel supply chain. To fill this void, we consider a two-period dual-channel model in which a manufacturer sells a durable product directly through both a manufacturer-owned e-channel and an independent dealer who adopts a mix of selling and leasing to consumers. Our results show that the manufacturer begins encroaching into the market in Period 1, but the dealer starts withdrawing from the retail channel in Period 2. Moreover, as the direct selling cost decreases, the equilibrium quantities and wholesale prices become quite angular and often nonmonotonic. Among other results, we find that both the dealer and the supply chain may benefit from the manufacturer’s encroachment. Our results also indicate that both the market structure and the nature of competition have an important impact on the player’s (dealer’s) optimal choice of leasing and selling.     

具过度自信零售商的双渠道供应链网络均衡研究

将零售商的过度自信行为纳入双渠道供应链网络均衡模型,研究了由供应商、分销商以及具过度自信行为的零售商构成双渠道供应链网络均衡问题。借助变分不等式以及互补理论,刻画了制造商、分销商以及过度自信零售商的最优行为,并构建了双渠道供应链网络均衡条件。解析分析了市场出现有利信息和不利信息两种情形下,零售商的过度自信行为对其订购决策的影响。最后,数值算例验证上述结论,并借助数值结果分析了零售商的过度自信行为对双渠道网络均衡的影响。     

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。     

Profit oriented supply chain network optimization

This paper proposes a novel mixed integer linear programming model to solve a supply chain network design problem. The proposed model deals with major issues for supply chains; product quality and cost. These issues are usually solved separately, but in this paper, we investigate effects of product quality on supply chain design and transportation flow. A trade-off between raw material quality, its purchasing and reprocessing costs was considered. Assuming decision maker (DM) wishes to work with a supplier which serves a low quality raw material; this raw material should be in need of reprocessing. To avoid the reprocessing costs, a supplier which serves a high quality raw material should be chosen but at this time the DM has to face a high purchasing cost. A supply chain network which consists of multiple suppliers, manufacturers, distribution centers and retailers is tried to be designed to accomplish aforementioned above trade-offs. The paper examines and discusses the relationship between product quality and supply chain design and offers several managerial insights.     

制造商广告激励策略对灰色市场的影响研究

在灰色市场的背景下,构建了由一个制造商和两个独立市场的零售商构成的两阶段供应链模型。依据产品估值将市场分为高端和低端市场,基于价格差异,低端市场的零售商为了实现投机套利会在高端市场中销售原本属于低端市场的产品。研究了灰色市场与制造商广告激励策略对供应链的影响问题。研究表明:若低端市场消费者对产品评价较低,灰色市场可增加制造商的利润;而低端市场消费者对产品估值较高时,灰色市场会减少制造商利润。进一步引入了制造商广告激励策略,得出广告激励不仅可以抑制灰色市场,而且可以在不降低高端市场零售商利润的情况下,让制造商和低端市场零售商的收益增加。     

Exploring greedy criteria for the dynamic traveling purchaser problem

Given a set of products and a set of markets, the traveling purchaser problem looks for a tour visiting a subset of the markets to satisfy products demand at the minimum purchasing and traveling costs. In this paper, we analyze the dynamic variant of the problem (D-TPP) where the quantity made available in each market for each product may decrease over time. We introduce and compare several greedy strategies and test their impact on the solution in terms of feasibility and costs. In particular, we study an incremental approach where an initial naive strategy is improved and refined by a number of variants. Some of the proposed heuristics take into account either one of the two objective costs, while others are based on both traveling and purchasing costs. Extensive computational results are also provided on randomly generated instances.     

Market share in a post-entry game

This paper investigates the dynamics of market share within a contemporary, real life, entry deterrence situation in the provision of National Health Service (NHS) pathology services. The major conclusion is that the previous Government's initiatives did not succeed in promoting competition in markets where existing NHS providers were operating significantly more efficiently than their neighbours. Evidence suggests managers were influenced more by potential competition from a new private sector entrant than by actual competition among existing providers. The effect of a new entrant is modelled as a perturbation of a pre-existing stable equilibrium in a seeming oligopoly influenced by market forces subject to Government regulation. Economic analysis of the market share which a new entry might gain shows that, on the assumptions made and contrary to expectations, the likely impact of Government regulation of NHS prices would be an increase in price per test in most of the market. Nevertheless the policy objective of improving quality at value for money prices was achieved for the near-monopoly provider within our case study area.     

The shelf space and pricing strategies for a retailer-dominated supply chain with consignment based revenue sharing contracts

Consider a two-echelon supply chain consisting of two manufacturers and a dominant retailer, such as big supermarkets like Walmart. Under a consignment contract with revenue sharing, the two manufacturers sell through the retailer two substitutable products whose demands are dependent on their shelf space and sales prices. The two manufacturers may compete horizontally for shelf space and pricing by three scenarios: Nash game, Stackelberg game, and collusion, and play vertically the retailer-Stackelberg game with the retailer. For each of these horizontal scenarios, we present all participators’ equilibrium strategies and their corresponding profits, based on which the impacts of manufacturers’ cost difference and moving sequence are investigated. Additionally, we discuss whether a horizontal collusion among manufacturers occurs when they choose their scenarios and whether centralization is always beneficial for the entire chain under the considered consignment contract. The study reveals the following results: (i) When the manufacturers compete horizontally, the high-cost manufacturer always sets a high-price and less shelf space strategy, while the low-cost manufacturer always adopts a low-price and more shelf space strategy, which is not affected by their moving sequence. If they collude horizontally, it is just reverse. (ii) When the two manufacturers compete horizontally, all participators’ equilibrium strategies and their corresponding profits are significantly influenced by manufacturers’ moving sequence. (iii) A horizontal collusion between the manufacturers can occur only when their cost difference is relatively small; this finding supplements existing literature. (iv) When the cost difference between manufacturers is relatively big, then centralization may be detrimental to the entire chain, which can explain why several supply chains adopt vertical competition strategies in practice. In addition, we find that these results still hold for the limited shelf space scenario and shelf-space limitation enhances the horizontal and vertical competition intensity by increasing shelf space fee.     

Integrated market selection and production planning: complexity and solution approaches

Emphasis on effective demand management is becoming increasingly recognized as an important factor in operations performance. Operations models that account for supply costs and constraints as well as a supplier’s ability to influence demand characteristics can lead to an improved match between supply and demand. This paper presents a class of optimization models that allow a supplier to select, from a set of potential markets, those markets that provide maximum profit when production/procurement economies of scale exist in the supply process. The resulting optimization problem we study possesses an interesting structure and we show that although the general problem is ${\mathcal{NP}}$ -complete, a number of relevant and practical special cases can be solved in polynomial time. We also provide a computationally very efficient and intuitively attractive heuristic solution procedure that performs extremely well on a large number of test instances.     

低碳环境下供应链差异化定价与协调机制研究

以低碳和普通产品两个制造商和一个零售商组成的两级供应链系统为研究对象,探讨了供应链的差异化定价与协调机制问题。求解得到了两制造商和零售商的最优定价策略及可行的低碳产品生产成本范围。研究发现:1)分散决策的差异化定价策略无法达到供应链协调;2)在可行的低碳产品生产成本范围内,低碳产品制造商、零售商和整个供应链系统的利润都随低碳产品生产成本的增加而减少,只有普通产品制造商的利润随低碳产品生产成本的增加而增加。因此,降低低碳产品生产成本是促进低碳产品推广的关键。针对分散决策造成供应链效率损失的情况,采用Shapley值法进行协调,并给出了契约协调机制。最后,通过算例分析了消费者价格敏感性变化和低碳产品生产成本上升对最优决策和供应链利润的影响。     

Heterogeneity and increasing returns may drive socio-economic transitions

There are clear benefits associated with a particular consumer choice for many current markets. For example, as we consider here, some products might carry environmental or ‘green’ benefits. Some consumers might value these benefits while others do not. However, as evidenced by myriad failed attempts of environmental products to maintain even a niche market, such benefits do not necessarily outweigh the extra purchasing cost. The question we pose is, how can such an initially economically-disadvantaged green product evolve to hold the greater share of the market? We present a simple mathematical model for the dynamics of product competition in a heterogeneous consumer population. Our model preassigns a hierarchy to the products, which designates the consumer choice when prices are comparable, while prices are dynamically rescaled to reflect increasing returns to scale. Our approach allows us to model many scenarios of technology substitution and provides a method for generalizing market forces. With this model, we begin to forecast irreversible trends associated with consumer dynamics as well as policies that could be made to influence transitions.     

由零售商负责回收的多期闭环供应链网络均衡

本文研究了零售商回收模式下多期闭环供应链网络均衡问题。制造商通过零售渠道将产品销售给消费者,以满足消费市场需求,同时消费产生的废旧品由零售商回收返回制造商处进行再制造,通过产品库存和回收废旧品连接相邻规划期。运用变分不等式理论和互补理论,分别刻画了制造市场、零售市场和消费市场的均衡,接着构建了多期闭环供应链网络均衡模型。利用变分不等式的投影收缩算法,对模型进行求解。算例着重分析了废旧品利用率对网络均衡状态和供应链成员利润的影响。结果表明:当制造商的废旧品利用率逐渐增加时,回收量逐渐增加,制造商的利润先减后增,零售商利润一直增加,而供应链总利润一直增加,供应链网络中的最优决策变量主要受到回收量约束的影响。     

随机需求下考虑风险行为的闭环供应链网络均衡模型

以变分不等式和均衡理论为基本研究工具,研究了随机需求与再制造率不确定条件下多个竞争型的供应商、制造商、零售商及消费市场的行为及均衡条件。对所建立的多级闭环供应链网络均衡模型,通过拟牛顿算法求解变分不等式,并仿真分析了再制造率、回收率以及风险因素对闭环供应链网络均衡结果的影响。结果表明:制造商提高再制造率能实现供应链成员利润的增加、产品价格的降低以及回收量的增加;制造商基于风险最小化和利润最大化相结合的原则进行决策能增加产品的交易量及企业的利润。     

Supplier–manufacturer coordination in capacitated two-stage supply chains

Manufacture-to-order is an increasingly popular strategy in commodity electronics and other similar markets where many different product configurations can be produced from common components. To succeed in this environment, manufacturers need to keep both cost and order fulfillment time low. In this article, we compare three different mechanisms that a manufacturer, whose revenues depend on order delays, may use to affect its component supplier’s inventory decisions. These mechanisms are specifying components inventory level, offering a share of the earned revenues to the supplier (called simple revenue sharing), and offering a two-part revenue-sharing scheme. We show that whereas the first two approaches do not lead to supply chain coordination, the two-part scheme does. We demonstrate with numerical experiments that up to a point, the component supplier benefits from having a high utilization of its production facility, whereas the manufacturer benefits from having excess production capacity.     

Planning for demand failure: A dynamic lot size model for clinical trial supply chains

This paper examines the optimal production lot size decisions for clinical trial supply chains. One unique aspect of clinical trial supply chains is the risk of failure, meaning that the investigational drug is proven unsafe or ineffective during human testing and the trial is halted. Upon failure, any unused inventory is essentially wasted and needs to be destroyed. To avoid waste, manufacturers could produce small lot sizes. However, high production setup costs lead manufacturers to opt for large lot sizes and few setups. To optimally balance this tradeoff of waste and destruction versus production inefficiency, this paper generalizes the Wagner-Whitin model (W-W model) to incorporate the risk of failure. We show that this stochastic model, referred to as the failure-risk model, is equivalent to the deterministic W-W model if one adjusts the cost parameters properly to reflect failure and destruction costs. We find that increasing failure rates lead to reduced lot sizes and that properly incorporating the risk of failure into clinical trial drug production can lead to substantial cost savings as compared to the W-W model without the properly adjusted parameters.