Consignment and vendor managed inventory in single-vendor multiple buyers supply chains

In this paper we model a consignment (CS) and vendor-managed inventory (VMI) policy for a single vendor and multiple buyers supply chain with known demand. We study three vendor–buyers partnerships: (i) the vendor and the buyers act independently, (ii) the vendor enters in a vendor-managed inventory consignment (VMI&CS) partnership with the buyers and (iii) the vendor and the buyer belong to a vertically integrated firm where a single decision maker decides about the ordering policies. We use relationships (i) and (ii) to study the benefits of the VMI&CS agreement. We provide analytical and numerical results. We find that such an agreement is more beneficial when the vendor has a flexible capacity. It is also more attractive to buyers when they have significant order costs and the vendor's setup cost is not large. Finally we find that under VMI&CS the vendor will tend to make more frequent shipments with smaller lots.     

A supply chain model with vendor-managed inventory,consignment, and quality inspection errors

This paper considers the integration between quality control and production inventory control in supply chain management. Specifically, we study the effect of inspection errors on the costs incurred in a supply chain system with a single vendor and multiple buyers. In this system, the vendor enters into a vendor-managed inventory (VMI) and a consignment stock (CS) partnership with several buyers. We assume that the items made by the vendor are not in perfect quality, but they contain a given proportion of defective units. We also assume that quality inspection of these items by the buyers is subject to sampling errors. Three cases indicating to different levels of supply integration are considered: VMI–CS system, traditional system and integrated system. For each case, a mathematical model is formulated, an optimum solution is developed, and a numerical example is solved.     

The effect of human factors on the performance of a two level supply chain

Many studies have addressed the issue of coordination in a supply chain. Coordinating mechanisms such as joint lot sizing models, quantity discounts and delay in payments have been used to achieve coordination in a supply chain. An important omission in this literature is the role of human factors, in particular inspection errors and learning, as a tool to improve coordination in a supply chain. In this paper, two coordination mechanisms found in the literature are integrated into a model for a two-level supply chain in which the incoming quality level of raw materials provided to a vendor by a set of suppliers is not perfect. The model addresses supply chain coordination by specifically investigating the role of different human factors on the total cost of the supply chain. These factors are: (a) type I and type II inspection errors; (b) learning in the production process; and (c) learning in quality at the suppliers’ end. Numerical examples are used to compare the costs of the three extensions with the base model (with no defectives).     

Technology investment effects in performance-based maintenance contracts

This work analyses the effects of a fixed initial investment in technology or infrastructure on performance-based maintenance contracts. We present a mathematical expression which reflects the trade-off between an upfront technology investment by the vendor and the cost of required future interventions. We develop a mathematical model of a performance-based maintenance contract that uses this technology trade-off expression and determines the value of the contract for each party. Contractually, the client indicates the duration of the contract and the optimal number of maintenance interventions to maximise asset availability; the vendor quotes the cost for the requested interventions. We study how the initial investment and the contract parameters affect the net present value for each party and the supply chain, demonstrating the existence of an optimal relation between the number of preventive maintenance interventions and level of investment. We derive the optimal contract parameters for the client, vendor and chain and show lack of coordination between the parties. To achieve coordination, we present a revenue sharing mechanism which maximises the value for the chain. Finally, an industry study case with data from the mining sector is presented. Results indicate that by investing and coordinating, the entire supply chain can improve the contract NPV by 149.7%.     

A vendor-managed inventory scheme as a supply chain coordination mechanism

In this paper, we have considered a vendor-managed inventory (VMI) arrangement in a supply chain (SC), where the buyer imposes a penalty for shipments exceeding an upper limit. We have shown as how the industry practice of VMI under penalty can be used as a SC coordination mechanism. The vendor can influence the buyer to increase the batch size without making the buyer worse off. We also discuss how such a penalty scheme may be derived. Further, we have established the equivalence of VMI under deterministic demand with that of quantity discount models, thus highlighting the need to incorporate both cooperation and coordination perspectives while analysing SC collaboration mechanisms.     

基于双边拍卖模型的易变质品供应链协作研究

以交易信用为协调激励机制,分析了完全信息及双边不完全信息时,持续变质的易变质品供应链的协调问题.在交易信用激励机制下,供应商通过允许下游企业延迟支付贷款而激励其提高采购批量,进而实现供应链的协调.在信息对称时,通过分析双方的个人理性约束而给出交易信用长度的取值范围;当双方对彼此的资金成本存在双边信息不完全时,通过构建双边拍卖模型给出各方的最优报价策略以及均衡的交易信用长度.最后的算例验证了文章的结论.     

An analysis of the general benefits of a centralised VMI system based on the EOQ model

Within a vendor-managed inventory (VMI) agreement, the upstream supply chain member (the vendor) takes responsibility for managing the inventory of the downstream member (the customer) within specific levels previously agreed upon without the need of orders from the customer side to be placed. Therefore, the vendor can focus on optimising production efficiency and capacity planning, while the customer has to improve forecast accuracy. This paper analyses the benefits a VMI agreement could bring for a one-supplier, multiple-customer case through analysing two cases: a supply chain managed in a traditional manner and VMI when both the vendor and the customers belong to the same organisation. The analysis is based on the economic ordering quantity (EOQ) formula and its related total cost, and the novelty is captured by evaluating one vendor, multiple buyers, and multiple product situations. The modelling is done so as to capture the needs and factors which occur within the pharmaceutical industry and a numerical application will be executed with data from one of the main leaders within the pharmaceutical field.     

存在尾货处理渠道的服装行业回购契约研究

考虑销售价格变动以及是否存在尾货处理渠道对服装行业供应链的影响,以博弈论为基础,在回购契约框架下建立了单次订购两阶段销售模型,通过分析不同时点回购契约对供应链协调性影响,得出：仅仅采用期末回购或期中回购不能实现供应链协调,通过设置合理的批发价格和回购价格,同时采用期末和期中回购能实现供应链系统协调;当供应链系统拥有对过季服装的处理渠道,并以合理价格对服装进行处理时,采用处理点策略能有效提高供应链系统整体效益。最后通过算例分析验证了相关结论的有效性。     

Scheduling of recovery actions in the supply chain with resilience analysis considerations

Supply chain engineering models with resilience considerations have been mostly focused on disruption impact quantification within one analysis layer, such as supply chain design or planning. Performance impact of disruptions has been typically analysed without scheduling of recovery actions. Taking into account schedule recovery actions and their duration times, this study extends the existing literature to supply chain scheduling and resilience analysis by an explicit integration of the optimal schedule recovery policy and supply chain resilience. In particular, we compute a schedule optimal control policy and analyse the performance of this policy by varying the perturbation vector and representing the outcomes of variations in the form of an attainable set. We propose a scheduling model that considers the coordination of recovery actions in the supply chain. Further, we suggest a resilience index by using the notion of attainable sets. The attainable sets are known in control theory; their calculation is based on the schedule control model results and the minimax regret approach for continuous time parameters given by intervals. We show that the proposed indicator can be used to estimate the impact of disruption and recovery dynamics on the achievement of planned performance in the supply chain.     

多供应商、多销售商的两级供应链库存模型研究

研究多个供应商、多个销售商组成的两级供应链的库存系统,在具有价格弹性的市场需求、允许供应商和销售商产生缺货的条件下,针对有无价格折扣的两种情况,分别建立了供应商、销售商各自的库存模型;结合满足供应商和销售商Pareto有效性,建立了含价格折扣的供应链系统整体盈利最大的库存模型.     

VMI下需求受库存和努力水平影响的供应链协调

针对一个实施VM I(供应商管理库存)的两级供应链,市场需求受供应商和零售商双重努力影响的问题,建立了基于协作关系的库存和努力水平决策模型。通过分析得出在分散决策下供应商选择的库存水平和零售商选择的努力水平均低于集中决策下的最优水平,供应链效率也较低。设计了一个成本分摊契约协调供应链。结果表明,该契约能将供应商和零售商紧密地联系在一起,且通过供应商和零售商的共同努力能获得比分散式决策下更大的利润。     

How to motivate vendor’s RFID adoption beyond mandate? A retailer’s perspective

Wal-Mart’s mandate of vendors’ RFID adoption has speeded the implementation of RFID, creating an innovative way of managing products and ushering in a new era of supply chain efficiencies. However, Wal-Mart’s action is widely controversial and hits troubles due to vendors’ protests. This research analyses how a retailer firm can stimulate its vendor to adopt this emerging innovation of supply chain management by using an incentive contract rather than a mandate. Such a contract should motivate the vendor to make costly efforts to adopt RFID, truthfully report the information of adoption cost, and execute RFID’s adoption at the retailer’s preferred timing. Established on the framework of the principal–agent theory (In economics, the principal–agent problem refers to the dilemma of how one party (the ‘principal’) could motivate the other party (the ‘agent’) to act in the best interests of one party (the ‘principal’) when both parties have different interests and information) and the real options theory (A real option theory investigates how valuable the flexibility (the ‘real options’) such as to the timing of the contract is when there is uncertainty in the contract), this paper derives such an incentive contract, discusses the effects of agency concerns and sheds substantive light on RFID’s adoption in a retailer–vendor dyad.     

Production lead-time hedging and coordination in prefabricated construction supply chain management

This paper studies a coordination scheme to solve a production lead-time hedging (PLTH) issue in the prefabricated construction supply chain management. To mitigate tardiness delivery owing to prefab production uncertainty, the project contractor (PC) prefers to inform the prefab factory (PF) an earlier due date which is termed as PLTH strategy. However, this strategy forces the PF to compress its production process. A balance must be optimised through the proposed PLTH coordination scheme. It includes a PLTH-related cost term, i.e. crashing money (charged by the PF to the PC) and a constant transfer term. Three models with different power structures are considered. Firstly, two Stackelberg games with alternative decision-making sequences and an equal power model are discussed to obtain the optimal PLTH amount and crashing money. Later on, a cost-sharing term is used to fairly allocate the system surplus. It is observed that this coordination scheme reduces the PLTH amount and ensures win–win coordination for both parties. Some interesting managerial implications are also obtained from comparison analysis and numerical studies.     

Vendor-managed inventory with consignment stock agreement for single vendor–single buyer under the emission-trading scheme

This paper presents a joint economic lot size (JELS) model for coordinated inventory replenishment decisions under the vendor-managed inventory (VMI) with consignment stock (CS) agreement and an emission-trading scheme. The paper assumes a single product that flows along a two-level supply chain system, with a single vendor and a single buyer. The total cost of the system is the performance measure, which is the sum of the vendor’s and the buyer’s total costs. The total cost includes the set-up and order costs, inventory holding costs, greenhouse gases (GHG) emissions tax and penalty costs. A mathematical model is proposed to determine: (1) the vendor’s production lot size quantity; (2) the number of shipments sent by the vendor to the buyer in a cycle; and (3) the production rate that minimises the total cost of the supply chain. Some numerical examples are carried out, as well as comparisons with the traditional JELS model for a classic two-level supply chain. Results show that the performance of the system is better when it is operated under a VMI with CS agreement, which is capable of reducing the traditional inventory holding costs and, for some values of given parameters, the GHG emissions tax and penalty costs.     

服务供应链的信息共享机制及绩效研究

文章研究的服务供应链包含一个服务供应商和一个服务集成商信息共享机制问题。服务供应商提供原始服务产品或活动给服务集成商,而服务集成商依次以附加值集成服务出售给客户。在不确定性市场环境下,客户服务需求量带有价格敏感和随机性的特征。在服务供应商和服务集成商之间,探析服务供应链的不同信息传输方式下信息共享机制问题,评估服务供应链的绩效,其结果强调服务业开展信息共享的必要性。     

不同碳排放政策下考虑碳减排投入的供应链协调

在考虑碳减排技术投入下,为了实现不同碳排放政策下的供应链协调,通过建立集中式和分散式决策下的供应链模型,根据供应链协调的条件,给出了供应链实现协调的契约形式及契约参数。为了确定不同碳排放政策下的最优订货量和最优碳减排率,通过对博弈模型进行优化,提出了具体的求解方法。数值计算结果表明：随着碳排放政策的变化,供应链的最优订货量、最优碳减排率和供应链的利润也将发生相应的变化,而生产成本、缺货损失、产品残值、销售价格、批发价格等参数变化不仅会影响最优订货量、最优碳减排率和供应链利润,还会影响收益共享比例、碳减排技术投入和碳排放成本的分摊比例。     

A distribution free newsvendor model with consignment policy and retailer’s royalty reduction

Reducing the system cost and achieving significant profit are the key factors for every successful business sector. A consignment contract under distribution-free approach may be a fruitful combination to achieve a profitable business. This model deals with a single-period newsvendor problem with a consignment policy. The consignment policy is an agreement between any two parties, named as the consignor and the consignee. Under Stackelberg approach, firms act as leader and follower. Both parties carry some parts of the holding cost instead of one. A new policy for paying the fixed fee to the consignee is introduced. This paper considers no specific probability distribution for customer’s demand except a known mean and standard deviation. An efficient approach is proposed to reduce the retailer’s cost and building a sustainable consignment contract. The solution of this model is obtained using distribution free approach. A comparison between the traditional supply chain policy and the consignment policy is established. The price-sensitivity on demand is analysed. Some numerical examples and graphical representations are given for both traditional and consignment policy. Result proves that consignment policy is dominating over the traditional policy and a significant reduction of retailer’s royalty is found.     

Internal incentives and operations strategies for the water-saving supply chain with cap-and-trade regulation

Faced with the rapid development of modern industries of agriculture, manufacturing, and services, water resources are becoming increasingly scarce. Industries with high water consumption are generally regulated by the government’s water cap-and-trade (CAT) regulation to solve the contradiction between the limited water supply and the rapid growing water demand. Supply chain equilibrium and coordination models under the benchmark scenario without water saving and CAT regulation, water-saving supply chain equilibrium and coordination models under the scenario without/with CAT regulation are developed, analyzed and compared. The corresponding numerical and sensitivity analyses for all models are conducted and compared, and the managerial insights and policy recommendations are summarized in this article. The results indicate that (1) Conducting water saving could improve effectively the operational performance of the water-saving supply chain under the scenario without/with CAT regulation. (2) The coordination strategy based on the revenue sharing contract could efficiently coordinate the water-saving supply chain, enhance water consumption reduction rate, and improve the operational performance of the water-saving supply chain. (3) The implementation of CAT regulation enhances effectively water-consumption-reduction in the water-saving supply chain and improves the operational performance of water-saving supply chain. (4) Simultaneous implementation of CAT regulation by the government and adopting coordination strategy by the water-saving supply chain would be superior to any other scenarios/strategies. (5) A suitable water cap based on the industrial average water consumption and historical water consumption data are beneficial for constructing reasonable and effective incentive mechanism. (6) A higher marginal trade price could induce more reduction in water consumption and create better operational performance for the manufacturer and water-saving supply chain, both under the equilibrium and coordination strategies.     

市场需求预测偏差下供应链协调

分两阶段研究了产品市场需求预测存在偏差情况下供应链协调问题。第一阶段，给出市场需求预测下的最优生产批量；第二阶段，首先给出需求预测偏差下的最优供给批量和供应链整体最考掣润，然后提出一种使供应链整体最大利润得以实现的协调机制。最后给出算例加以说明。     

供应链订货与营销渠道协调的主从对策模型

研究了供应链订货与营销渠道的协调问题,考虑了零售商具有订货成本缩减和营销投资成本,建立了供应链订货与营销渠道协调的Stackelberg主从对策模型.这一模型中,主方零售商具有产品零售价格和投资决策权,从方供应商具有产品批发价格决策权.分析了零售商四种投资策略,针对每种投资策略下的协调模型进行了数值仿真,结果表明在零售商订货成本缩减和营销之间进行投资协调能够同时增加零售商和供应商利润.