Supplier hoarding,government intervention,and timing for post-disaster crop supply chain recovery

This work presents a multi-methodological approach to address the issue of post-disaster crop supply chain recovery under the influences of government intervention and supplier hoarding intention. A conceptual model which characterizes the antecedents of supplier hoarding intention is proposed, and validated using survey data. Grounded in the empirical study, an analytical model is then proposed for decision analysis of a two-tier crop supply chain recovering from post-disaster supply disruptions. Analytical results indicate that hoarding behavior reduces the time taken by supply chain members for supply recovery; and however, contributes to mixed effects on the expected profits of supply chain members.     

On the use of RFID in the management of reusable containers in closed-loop supply chains under stochastic container return quantities

This paper studies a closed-loop supply chain that uses containers for transporting products from a supplier to a retailer. At the retailer, used containers are collected and returned to the supplier. The supplier inspects returned containers, and either repairs and reuses or disposes them. This paper studies the case where the fraction of containers that are returned to the supplier is stochastic, and where an RFID system can be used to support the tracking of container positions in the supply chain. The use of RFID leads to improved information on the return of containers and better return predictability as well as higher return rates, which we model as an increase in the mean return rate of containers and a reduction in return variance. The paper first develops a mathematical planning model for this scenario, and it then studies how the use of RFID impacts the performance of the system. In addition, it analyzes under which conditions the use of RFID is economical, and in which situations traditional container systems should be preferred.     

The value of information on supply risk under random yields

For companies facing challenge of managing unreliable supply sources, one of the operational goals is to increase the overall profit by improving performance of uncertain supply. We here develop stochastic decision frameworks which evaluate necessary information about uncertainties and help newsvendor and suppliers to enhance supply reliability. We first analyze the newsvendor’s purchasing decision under supply uncertainty and the derived decision framework is used to identify stochastic dominance conditions. We found that partial supply risk information is sufficient to determine regular ordering quantity, but to improve the overall profit, it is important to gather more information about stochastic dominance conditions.     

供应链中采购与库存协调的研究

通过对二级供应链中采购和库存协调问题的研究,提出了两阶段协调方法,第一阶段在采购方内部进行协调,制定采购计划;第二阶段由采购方与供应方进行协调,从而降低供应链的总成本,获得更多的总利润,为使采购方能采用协调机制,可通过数量折扣的方法还利于采购方,达到采购方与供应方的双赢。     

基于电子商务的供应链管理集成技术研究

针对传统的供应链管理难以实现企业与合作伙伴间对信息的实时同步共享,不能充分支持和体现供应链管理的战略优势和系统特征的问题,在分析基于电子商务的供应链管理集成模式的基础上,给出以BizTalk为主要开发平台的电子商务供应链管理系统集成的技术架构,使供应链上的节点企业可以真正实现与供应商、经销商和客户的信息共享。     

Dual sourced supply chains: the discount supplier option

In this paper, we examine the dynamics of a supply chain that has the option of using two suppliers – one reliable, and the other unreliable. We characterize the unreliable supplier with long lead-time mean and variance. Although the use of the unreliable supplier might potentially warrant higher inventory and transportation costs, it is attractive because of the willingness of the supplier to provide a discount on the purchase price. We analyze the cost economics of two suppliers in a broader inventory-logistics framework, one that includes in-transit inventories and transportation costs. In this broader perspective, we provide a simple heuristic and sample exchange curves to determine: (i) if the order should be split between the suppliers; and (ii) if the order is split, the amount of discount and the fraction ordered to the secondary supplier to make order-splitting a worth-while policy. ©     

A supply chain model of vendor managed inventory

This research evaluates how vendor managed inventory (VMI) affects a supply channel. Specifically, VMI always leads to a higher buyer's profit, but supplier's profit varies. In the short-term, VMI is found to reduce total costs of the channel system, but under certain cost conditions between buyer and supplier, it could decrease the purchasing price and supplier's profit. In the long-run, it could more likely increase supplier's profit than in the short-run. Finally, VMI is an effective supply chain strategy that can realize many of the benefits obtainable only in a fully integrated supply chain.     

The impact of transportation disruptions on supply chain performance

This paper investigates the effect of a transportation disruption on supply chain performance using system dynamics simulation, comparing a traditional supply chain and a vendor managed inventory system (VMI) when a transportation disruption occurs between 2 echelons in a 5-echelon supply chain. The greatest impact occurs when transportation is disrupted between the tier 1 supplier and warehouse. In the traditional structure the retailer, warehouse, and tier 1 supplier experience the greatest inventory fluctuations and the highest goods in transit to their facilities. These impacts are less severe for the VMI structure, although unfilled orders are approximately the same for each.     

Multiple sourcing under supplier failure risk and quantity discount: A genetic algorithm approach

This paper investigates an order allocation problem of a manufacturer/buyer among multiple suppliers under the risks of supply disruption. A mixed integer non-linear programming (MINLP) model is developed for order allocation considering different capacity, failure probability and quantity discounts for each supplier. We have shown that the formulated problem is NP-hard in nature and genetic algorithm (GA) approach is used to solve it. The model is illustrated through a numerical study and the result portrays that the cost of supplier has more influence on order quantity allocation rather than supplier’s failure probability.     

Global supply chain design: A literature review and critique

In this paper, we review decision support models for the design of global supply chains, and assess the fit between the research literature in this area and the practical issues of global supply chain design. The classification scheme for this review is based on ongoing and emerging issues in global supply chain management and includes review dimensions for (1) decisions addressed in the model, (2) performance metrics, (3) the degree to which the model supports integrated decision processes, and (4) globalization considerations. We conclude that although most models resolve a difficult feature associated with globalization, few models address the practical global supply chain design problem in its entirety. We close the paper with recommendations for future research in global supply chain modeling that is both forward-looking and practically oriented.     

Coordination with a backup supplier through buy-back contract under supply disruption

This paper studies a buy-back contract between a buyer and a backup supplier when the buyer’s main supplier experiences disruptions. The expected profit functions and the optimal decisions of the contract players are derived through a sequential optimization process. The common properties of the contract as well as the differences under the demand uncertainty and the main supplier’s recurrent supply uncertainty are explored through comparative studies and numerical examples. The study contributes to the literature by providing a better understanding of the impacts of demand and supply uncertainties and by shedding insights on the value of a backup supply.     

A three-level supply chain network design model with risk-pooling and lead times

This paper considers a single-sourcing network design problem for a three-level supply chain consisting of suppliers, distribution centers (DC’s) and retailers, where risk-pooling strategy and DC-to-supplier dependent lead times are considered. The objective is to determine the number and locations of suppliers and DC’s, the assignment of each location-fixed DC to a supplier and that of each retailer to a DC, which minimizes the system-wide location, transportation, and inventory costs. The problem is formulated as a nonlinear integer programming model, for which a two-phase heuristic solution algorithm is derived based on the Lagrangian relaxation approach. Numerical experiments show that the proposed heuristic is effective and also efficient.     

Diversification strategy with random yield suppliers for a mean–variance risk-sensitive manufacturer

We consider the diversification strategy for a mean–variance risk-sensitive manufacturer with unreliable suppliers. We first analyze the linear model and find that the suppliers are selected according to the descending order of their contributed marginal expected profit, and increasing the manufacturer’s risk-averseness leads to a more even allocation of demand across the suppliers. Then, we study the general newsvendor model. By approximating the leftover inventory with a normal distribution, we establish the general properties of the active supplier set and show that the supplier selection rule is similar to that under the risk-neutral setting when the demand uncertainty is large. Moreover, we conjecture that the selection rule also applies when the demand uncertainty is low, which we verify with an extensive numerical study. Our paper makes two contributions: First, we establish the properties of the optimal diversification strategy and develop corresponding insights into the trade off between cost and reliability under the mean–variance framework. Second, we perform comparative statics on the optimal solution, with a particular emphasis on investigating how changes in the supplier’s cost or reliability affect the risk-averse manufacturer’s ordering decisions and customer service level.     

Robust optimization for United States Department of Agriculture food aid bid allocations

The U.S. Department of Agriculture (USDA) currently uses a bidding system to determine carriers and suppliers that would partner in providing food aid annually in response to global emergencies and famine. We mimic the USDA approach via a robust optimization model featuring box and ellipsoid uncertainty frameworks to account for uncertainties in demand, supplier and carrier bid prices. Through a case study utilizing historical invoice data, we demonstrate our model applicability in improving ocean carrier and food supplier bid pricing strategy and similar supply chain network optimization problems. Through a validation algorithm we demonstrate the value of our robust models.     

面向电子供应链的企业物流信息系统模型研究

面向电子供应链的企业物流信息系统的开发和建设,有助于实现企业、供应商、销售商之间的协调发展,减少库存,降低操作成本,缩短交易时间等。根据电子供应链的网络环境特点,在研究制造业企业物流一般流程的基础上,根据主、辅制造商物流流程,提出企业物流信息系统的参考模型结构设计。     

Truthful multi-unit multi-attribute double auctions for perishable supply chain trading

This paper aims to propose multi-attribute double auctions for perishable supply chain trading (PSCT). We first construct a multi-unit/single-unit multi-attribute double auction (MS-MDA) for PSCT where suppliers can submit bids on a single unit of one item (i.e., single output restriction). We then relax the single output restriction and propose a multi-unit multi-attribute double auction (M-MDA) for PSCT in which each supplier offers multiple units of one item. Both the MS-MDA and M-MDA mechanisms are incentive compatible, individually rational, budget balanced and computationally efficient. The computational study shows that all proposed mechanisms are of high allocation efficiency and practically implementable.     

Integrating the warehousing and transportation functions of the supply chain

Electronic commerce and associated business-to-business transaction capabilities have changed the way in which supply chains operate. The Internet has enabled information exchange on an unprecedented scale, often at a pace too fast for normal consumption. Companies are not equipped to make effective use of data from warehouse management systems––which contain information on supplier/customer warehouse inventory levels and key customer ordering patterns––and transportation management systems––within which information pertaining to the location of important supply chain assets such as products or vehicles is typically stored. These systems are key factors in integrating the physical flow of goods along the supply chain. The integration of these systems leads to global inventory visibility, which, in turn, leads to reduced costs and improved customer service by decreasing shipping and receiving cycle times, increasing shipment and inventory accuracy, and decreasing lead-time variability. This paper examines the total cost benefits that can be achieved by suppliers and warehouses through the increased global visibility provided by an integrated system. We develop a discrete event simulation model of a multi-product supply chain to examine the potential benefits to be gained from global inventory visibility and trailer yard dispatching and sequencing techniques. Experimental results demonstrate the potential for this integrated paradigm to improve customer service through improved efficiencies, reduced costs, and reduced lead-time variability.     

Post-disaster grain supply chain resilience with government aid

Assessing the disruption and resilience of the agricultural grain supply chain is critical to ensure grain supply and stabilize grain price in the final market. This research proposes a quantitative model to analyze how a grain processor regains robustness when supply is disrupted by a natural disaster upstream, and how this disruption affects grain retailers downstream. Two supply chain recovery methods, contingent sourcing and government aid, are considered for grain processor recovery. The results show that (1) a processor prefers timely full recovery, and (2) government aid as an intervention means is indispensable but cannot fully replace the backup supplier.     

Social responsibility and supply chain relationships

We use the term purchasing social responsibility (PSR) to describe the involvement of purchasing managers in socially responsible activities. The purpose of the research is to examine the potential impact that PSR might have on supply chain relationships. Our findings suggest that PSR has a direct and positive impact on supplier performance, as well as an indirect, mediated effect through improved trust and cooperation. These findings hold important implications not only for purchasing managers but also logistics managers in the areas of customer service, distribution, and business-to-business marketing.     

供应链中基于VMI库存与运输协调问题的研究

通过对1个供应商、N个零售商组成的供应链形式的协调问题研究,提出了在VMI系统中协调库存与运输的配送策略。这种配送策略假设需求是Poisson随机过程,以更新理论为基础,基于供应商有权持有小额定单,直到定单数量到达一定程度时进行一起派送,即通过规模经济运输,达到降低成本的目的。