供应中断和需求扰动下供应链竞合关系研究

考虑供应中断和需求扰动情境下2个供应商和1个零售商组成的两级供应链系统,构建了合作、静态非合作、嵌套式静态非合作3个博弈模型,分析集中式、分散式供应商竞争与合作情形下的零售商采购策略与供应商定价策略。研究表明,当市场需求增大时,分散式供应商合作情形下供应链整体利润最高;当市场需求减少时,集中式供应链整体利润最高。当权衡供应商订货成本与产品供应稳定性时,零售商倾向与相对稳定的供应商合作;当供需同时不确定时,仅较稳定的供应商受影响。     

Blockchain adoption or contingent sourcing? Advancing food supply chain resilience in the post-pandemic era

In the post-pandemic era, food supply chains and firms therein are facing unprecedented severe challenges, because once infection is detected, numerous products must be recalled or abandoned, and both suppliers and retailers in the supply chain suffer enormous loss. To survive under the pandemic, retailers have adopted different sourcing strategies, such as contingent sourcing, which, in turn, affect the upstream suppliers and hence the resilience of the whole supply chain. With the rapid development of digital technologies, retailers nowadays can utilize blockchain as a reliable and efficient way to reduce product risk and hence advance the resilience of food supply chains by improving product traceability and inspection accuracy, and making sourcing transparent. In this paper, we develop a game-theoretic model to investigate the interrelation between the retailer’s decisions on blockchain adoption and sourcing strategies. We consider that a retailer originally orders from a risky supplier while conducting an imperfect inspection to detect infected products before selling. The retailer may speculatively keep on ordering from the risky supplier or adopt contingent sourcing by ordering from an alternative safe supplier. The retailer also has an option to implement blockchain to improve the inspection accuracy and product traceability. We derive the optimal retail prices under different sourcing strategies with and without blockchain adoption and then analyze the incentives for sourcing strategy and blockchain adoption. Then, we identify the conditions of an all-win situation for food retailer, supplier, supply chain resilience, and consumers with/without government subsidy. Finally, we extend to consider the situation that some consumers have health-safety concerns and preferences for blockchain adoption.     

Using backup supply with responsive pricing to mitigate disruption risk for a risk-averse firm

We consider a risk-averse firm’s sourcing problem with two suppliers: a dedicated one and a backup one. The dedicated supplier charges a lower wholesale price, but faces potential disruption risk. The backup supplier is assumed to be perfectly reliable, but charges a higher wholesale price. To mitigate the disruption risk, the firm uses a joint backup supply and responsive pricing strategy. We consider three common backup strategies between the firm and the backup supplier: advance purchase, reservation and contingency purchase. We derive under what conditions each strategy could be optimal. The results show that the thresholds that determine the optimal backup supply strategy are affected by the risk aversion level. When the risk aversion level is not extremely high, the firm should choose among the three backup suppliers by considering the disruption probability and the reservation fee. Firms with a higher risk aversion level tend to rely more on ex-ante preventive efforts (i.e. reservation or advance purchase strategies). When the risk aversion level is extremely high, the firm never considers the contingency purchase strategy, even for a low-probability disruption event. Additionally, market conditions yield non-negligible influences on the firm’s strategic choices due to the existence of risk aversion.     

Coordinating a supply chain under uncertain demand and random yield in presence of supply disruption

A two-echelon supply chain involving one manufacturer and one retailer for a single product is considered in this paper. The end customers’ demand is assumed to be random. The production of the manufacturer is subject to random yield, and there is a possibility of supply disruption in which case no item from her can reach the retailer. The retailer has a backup supplier who is costlier but perfectly reliable, and is having a limit up to which he may deliver. In addition to placing an order to the manufacturer, the retailer is allowed to reserve a quantity from the backup supplier in the ordering period; he may buy up to the reserved quantity after realising actual market demand in the trading period. Aiming at studying the effects of the various uncertainties involved in the chain on the optimal decisions, we develop and analyse centralised and decentralised models. We also propose a contract mechanism to coordinate the chain and find threshold conditions for which the coordinated model would collapse. Numerical examples are provided to illustrate the developed model.     

Ex post demand information sharing between differentiated suppliers and a common retailer

We consider ex post demand information sharing in a two-echelon supply chain in which two suppliers sell differentiated products through a common retailer. We model three scenarios of information sharing to characterise the conditions under which information sharing may benefit or hurt different players: (1) no supplier is informed; (2) only one supplier is informed; and (3) both suppliers are informed. We find that the retailer may voluntarily share the low demand information when the product differentiation and demand magnitude satisfy certain conditions. In contrast, the retailer has no incentive to share the high demand information, even though this information benefits the suppliers. To achieve information sharing, we propose a side payment mechanism, which allows benefitted players to subsidise hurtful players. Finally, we extend our model by considering a situation where the suppliers have limited capacity and may invest to ramp up production capacity to satisfy a high demand.     

Horizontal cooperation and information sharing between suppliers in the manufacturer–supplier triad

In this paper, we analyse a collusion and information-sharing problem between two suppliers in a manufacturer–supplier triad. The manufacturer treats one supplier as a strategic supplier and the other as a backup. While the strategic supplier offers modules of good quality but longer lead times, the backup supplier offers modules with inferior quality but shorter lead times. If there are urgent orders, the manufacturer must turn to the backup supplier. However, it is difficult for the manufacturer to estimate whether the urgent supplier has put extra effort into their production. We formulate this problem by assuming that the urgent supplier has either low or high production costs. To take advantage of the competition between two suppliers, the manufacturer can design a contract menu that defines total payment and lead times, under which both suppliers may be worse off. Meanwhile, it is possible for the suppliers to tacitly form a coalition, and to even share the private cost information. We study this problem by formulating it as a three-stage game. Furthermore, we investigate the variation of profits for each part of the supply chain. We find that the manufacturer is worse off when suppliers cooperate or share private information. Both suppliers, however, can benefit from cooperation and information sharing.     

基于演化博弈模型的供应链利他偏好动态演进研究

考虑供应链成员利他偏好行为和动态演进特征,分别在线性需求和非线性需求下建立相应的供应链决策模型。首先在短期内通过计算博弈支付矩阵对零供双方的均衡策略进行分析,其次在长期内运用演化博弈理论对零供双方进行单独演化分析、交互演化分析,最后将2种需求条件下供应链成员均衡策略进行比较,进而研究零售商利他偏好对供应链长期决策的影响。研究结果表明,短期内,供应商均衡策略依赖于零售商策略,而零售商均衡策略不受供应商影响且总是采取“偏好利他”策略;长期内,2种需求条件下零供博弈的均衡策略均为供应商采取“激励”策略、零售商采取“偏好利他”策略。此外,零售商利他偏好能提高供应商利润并使零售商实现效用最大化,进一步促进双方合作。     

Review of supplier diversification and pricing strategies under random supply and demand

Uncertainties of supply and demand are two major sources of risk in any supply chain. As a result, the companies are implementing different strategies to mitigate the effects of these risks. Supplier diversification and responsive pricing are two of the main strategies that are used to mitigate the supply and demand risks. In supplier diversification, a firm uses multiple channels of sourcing while in responsive pricing, a firm manipulates demand through pricing to mitigate supply and demand risks. In this paper, we review lot-sizing problems when supply and demand are random. We focus on studies that have considered supplier diversification or responsive pricing as a mitigation strategy. We classify the studies based on their main assumptions and summarise their major findings. Finally, we present some directions for future research. Part of what we have found is that most studies that use multiple decision makers have focused on cases where information is complete and non-cooperative. There is a need to consider more realistic situations when there is information asymmetry between the decision makers. In addition, we have found that there is a lack of studies that look at the impact of joint ordering and pricing in the existence of multiple suppliers.     

Order timing strategies in a single-supplier,multi-retailer system

The timing of retailer order placement is an important factor in supply chain performance in systems with uncertain end-customer demands. Retailers often prefer short order lead times, which permits the resolution of demand uncertainty prior to order placement, and reduces the risks associated with excess inventory. Suppliers, in contrast, prefer long lead times, in order to match supply output with retailer demand. These conflicting preferences create tension between a supplier and retailers regarding order timing preferences. This paper considers order timing preferences within a strategic framework involving a supplier and one of its retailers in a multiple-retailer system. We identify and explore several mechanisms a supplier can use within this framework to induce early retailer order placement and improve expected cost performance.     

需求和成本同时发生偏差时供应链协调研究

研究一个供应商和一个零售商组成的供应链,分别在一体化供应链、分散化供应链发生突发事件的情况下,使用收益共享合约协调该供应链。研究发现,收益共享合约在稳定条件下能实现该供应链的协调;当突发事件导致价格敏感系数和供应商的生产成本同时与其预测值发生偏差时,原有的协调被打破,改进的收益共享合约可协调价格敏感系数和成本偏差的分权供应链。     

供需双重不确定下链与链竞争的博弈分析

研究了分别由1个零售商和1个供应商构成的两条供应链之间的竞争问题,讨论了供应中断风险和需求不确定对于竞争的供应链的影响。分析了协调竞争、混合竞争、非协调竞争3种供应链结构下的最优订货量和契约参数。研究发现在一定的收益共享系数范围,供应链协调竞争成立。最后通过数值计算,分析了参数对最优订货量的影响,得到了管理启示。     

随机需求下零售商主导供应链的订单决策分析

已有关于供应链中订单决策问题的研究大都是从制造商主导交货期的角度来研究订单价格和交货期,但在"集群"环境下和市场随机需求下,零售商拥有购买决策权,主导订单时间。通过引入制造商声明策略,研究了在随机市场需求下和市场不确定性与观察时间相关联下,制造商—零售商之间的订单决策问题。建立了不同策略下的零售商订单决策模型,分析了制造商声明策略对零售商订单决策的影响,推导了制造商最佳利润率的求解算法。研究表明:制造商的不加班策略对自身始终是最有利,但最优利润率受市场不确定影响;零售商的订单决策受制造商声明策略和订单价格的影响。最后,通过算例给出制造商的最佳利润率以及市场不确定性对双方收益的影响。     

Supply chain resilience for single and multiple sourcing in the presence of disruption risks

This paper investigates the use of sourcing strategies to achieve supply chain resilience under disruptions. The coping strategies considered are single and multiple sourcing, backup supplier contracts, spot purchasing, and collaboration and visibility. Collaboration and visibility, which affect suppliers’ recovery capabilities and a buyer’s warning capability, have not been similarly modelled in the past. A scenario-based mathematical model is developed such that it considers objectives under uncertainties including disruption risks and operational risks. A broad numerical study examines its output for various risk attitudes in a decision-maker, ranging from risk neutral to risk averse. The sensitivity of procurement strategies to other key parameters such as recovery and warning capabilities is examined. One of the major findings is that buyer’s warning capability plays a vital role in enhancing supply chain resilience. We seek to build on these efforts to further support disruption planning and mitigation and to obtain a deeper understanding of the relationship between supply chain characteristics and resilience.     

Modelling carbon trading and refrigerated logistics services within a fresh food supply chain under carbon cap-and-trade regulation

Carbon cap-and-trade regulation is widely adopted to reduce carbon emissions. Under this regulation, we propose a carbon trading mechanism considering refrigerated logistics services in a fresh food supply chain. In addition to supplying fresh food, the supplier offers refrigerated logistics services and overstocked carbon emission permits to the retailer. We study the decisions on the price of emission permits traded within the supply chain, the retail price and the price of refrigerated logistics services in different carbon trading options, without carbon trade, inner carbon trade, inner and outer carbon trade. Pricing strategies for fresh food, emission permits and refrigerated logistics services are provided for supply chain members. We also reveal the relationship between carbon trading and refrigerated logistics services, and investigate their joint influence on the supplier–retailer cooperative relationship. In addition, it is shown that with the implementation of a transfer payment mechanism, supply chain members are motivated to participate in the carbon trading mechanism, which has advantages including improved resource utilisation and more competitive supply chains.     

Random yield and coordination mechanisms of a supply chain with emergency backup sourcing

This paper considers a supply chain in which a buyer purchases finished items from a contracting supplier to satisfy a stochastic market demand, where the supplier’s production is subject to random yield. We assume that the buyer can make up the shortage by sourcing from an emergency backup supplier. We develop two Stackelberg game models, i.e. buyer-Stackelberg (BS) model and supplier-Stackelberg (SS) model, and find that the decentralised BS model results in a higher stocking factor of supplier’s input than the decentralised SS model. Compared with BS model, the buyer in SS model performs more explicit order plan, and we find that only when the actual yield of the supplier is insufficient, the buyer would use emergency backup sourcing to make up the shortage. When the manufacturing operation of the supplier is in the good state, the buyer only orders a certain amount and has some leftover. When the actual yield of the supplier is moderate, the buyer uses up every item produced from the supplier regardless of the yield rate. Comparing both channel structures, SS operation is a more effective way of controlling both inventory cost and backup sourcing cost, and it can be beneficial for each player as well as for the whole channel. Finally, we develop the coordination mechanism for each channel to investigate the issues of risk handling and risk sharing for uncertain demand and uncertain yield.     

Flexible strategies under supply disruption: the interplay between contingent sourcing and responsive pricing

Due to possible supply disruptions because of a low-cost unreliable supplier, a firm may use a high-cost reliable supplier as an additional regular supplier (dual sourcing) or an emergency backup supplier with an extra emergency cost (contingent sourcing). We consider the firm's sourcing problem when the pricing decision is made before any supply uncertainty is resolved (committed pricing) or after the supply state is realised (responsive pricing). By comparing the relative value of responsive pricing in contingent sourcing to that in dual sourcing, we study the relationship between contingent sourcing and responsive pricing in mitigating supply disruption risks. We show that the emergency cost and potential lost sales caused by disruption probability jointly impact the interplay of these two strategies. More specifically, when the emergency cost is low and the potential lost sales are lower under contingent sourcing than that under dual sourcing, contingent sourcing and responsive pricing are substitutes; otherwise, they are complements. Furthermore, we examine how disrupted capacity, i.e. the quantity that the unreliable supplier can deliver when disrupted, impacts the interplay, and find that the probability of the substitution relationship becomes higher when the disrupted capacity increases. We also find that under committed pricing, contingent sourcing is not optimal for any value of disruption probability when the emergency cost is high, a phenomenon that does not exist under responsive pricing.     

Consumer search,transshipment, and bargaining power in a supply chain

We study a decentralised supply chain with one manufacturer and two symmetric retailers who could transship their excess inventory between each other. Without transshipment, the retailer’s unsatisfied customers search and buy the product at the other retailer with some probability. With transshipment, the retailer can transship the other retailer’s excess inventory to fulfil its own unmet demand. However, a transshipment price is often charged by one retailer for transshipping goods to another. We show the retailer’s profit is unimodal in the transshipment price, and the manufacturer’s profit increases in the customer search probability. Although the retailer’s preference over transshipment depends on the magnitude of search probability and transshipment price, the retailer may always prefer the transshipment no matter their magnitude. We then study the effect of bargaining power over the transshipment decision (whether to transship between retailers and at what transshipment price). Our analysis suggests that the manufacturer always prefers to control the transshipment price rather than to control whether to transship, while the retailer can prefer both. We also find that increasing bargaining power always benefits the manufacturer but could hurt the retailer. We finally check the robustness of our results by investigating the case with asymmetric retailers     

Trust-embedded coordination in supply chain information sharing

This paper studies supply chain coordination with trust-embedded cost-sharing contract. In a two-tier supply chain, a retailer (she) and a supplier (he) make their private demand forecasting individually. The retailer places soft-orders, which are costless, non-verifiable and cancellable before shipping, to the supplier. After that, the supplier relies on the retailer’s ordering information to update his demand evaluation and prepare his capacity. How much the supplier relies on the retailer’s ordering information is specified by trust, which is a kind of psychological feeling and affected by multiple factors. When the supplier does not fully trust the retailer, he tends to prepare a conservative capacity to avoid over-production. To coordinate the supply chain, a two-stage coordination process is proposed. At the first stage, the supplier and retailer negotiate a cost-sharing rule to bind soft-orders. At the second stage, the retailer places a soft-order and decides whether or not to bind it referring to the cost-sharing rule. After that, the supplier determines his optimal production capacity. We show that the retailer and supplier value trust differently in the experimental studies. We also find that there is a threshold of negotiation power for the supply chain partners which means the supplier’s/retailer’s expected profit drops down if his/her negotiation power exceeds certain thresholds. The experimental studies also show that the proposed the two-stage coordination is effective.     

Supplier selection under risk of delivery failure: a decision-support model considering managers’ risk sensitivity

This paper studies the problem of supplier selection and order allocation in a retail supply chain (comprising suppliers, a central purchasing unit and outlets) under disruption risk. The final demand is deterministic. Suppliers are located in different geographic areas, and supplies are subject to a positive probability of disruption. Different capacity and failure probabilities for each supplier are considered. Our analysis focuses on the insurance versus profitability trade-off faced by a supply manager who buys from suppliers for the outlets. Instead of determining optimal decisions given an objective function and the risk sensitivity of the decision-maker, we use a mixed integer linear programming approach to provide decision-making support that shows a supply manager the ‘elasticity of (expected) losses versus (expected) profits’. Under this model, and depending on the profit-and-loss targets, a supply manager of known risk sensitivity (i.e. risk aversion and loss aversion) can make better decisions when choosing suppliers. Moreover, taking into account, the impact of the share of fixed costs that must be covered by the operation, we consider the net values of expected profit and loss. We discuss the potential influence of the level of the firm’s fixed costs on the supply strategy. In particular, we show how the minimum value of the gross margin needed for the strategy’s profitability affects that strategy. A numerical application is conducted to illustrate the contribution of our decision-making support mechanism, and several managerial insights are obtained.     

Developing a resilient supply chain through supplier flexibility and reliability assessment

In this study, we examine the optimal allocation of demand across a set of suppliers in a supply chain that is exposed to supply risk and environmental risk. A two-stage mixed-integer programming model is used to develop a flexible sourcing strategy under disruptions. Our model integrates supplier selection and demand allocation with transportation channel selection and provides contingency plans to mitigate the negative impacts of disruptions and minimise total network costs. Finally, a numerical example is presented to illustrate the model and provide insights. The findings suggest that developing contingency plans using flexibility in suppliers’ production capacity is an effective strategy for firms to mitigate the severity of disruptions. We also show that flexibility and reliability of the suppliers and regions play a significant role in determining contingency plans for during disruption. Findings generally show that highly flexible suppliers receive less allocation, and their flexible capacity is reserved for disruptions. For firms that do not incorporate risk management into supplier selection and allocation, the recommendation is to source from fewer, more reliable suppliers with less risk of disruption. Our findings also emphasise that the type of disruption has important implications for supplier selection and demand allocation. This study highlights the supply chain risk management strategy of regionalising as a means for minimising the impact of environmental disruptions.