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。     

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.     

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.     

Multi-level inventory management decisions with transportation cost consideration

In this article we address specific inventory management decisions with transportation cost consideration in a multi-level environment consisting of a supplier–warehouse–retailers. We develop two models – namely, decentralized ordering model and centralized ordering model to investigate the effect of collective ordering by retailers on the total inventory cost of the system. A numerical study shows that the proposed model is robust and generates reasonable cost savings. The models have potential in several multi-level applications such as fresh or frozen food delivery to stores of different supermarkets or the supply of medicine to a number of hospitals from a wholesaler.     

基VMI的供应链利润模型研究

研究了供应链管理环境下新的库存策略。建立了基于VMI的有初始库存、允许库存短缺、缺货需补充、补充具有延时的供应链利润模型，并对该模型进行了供应链总的库存相关成本及供应商的库存相关成本分析。     

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. ©     

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.     

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。     

Optimizing a bi-objective inventory model of a three-echelon supply chain using a tuned hybrid bat algorithm

This paper presents a bi-objective VMI problem in a single manufacturer-single vendor multi-retailer (SM-SV-MR) supply chain, which a redundancy allocation problem is incorporated. In the hybridized problem, a manufacturer produces a single item using several machines that work in series, and stores it in a warehouse to replenish one vendor who delivers it to several retailers using the shortest possible route. A novel meta-heuristic, called hybrid bat algorithm (HBA), with calibrated parameters is utilized to find a near-optimum solution. To show the efficiency of HBA, the results are compared to the ones using the traditional BA and a genetic algorithm.     

Impact of decision sequence on reliability enhancement with supply disruption risks

This paper considers a supply chain that consists of a manufacturer and a supplier who faces disruption risks. We investigate the impact of decision sequence on the supplier’s endogenous reliability enhancement and the firms’ equilibrium pricing strategies. The supply chain reliability achieves a higher level under the supplier–leader game, but this does not always lead to a higher payoff for the supply chain. Each firm prefers to make the decision first, while any decision sequence can become dominant for the supply chain. We also show that the supply chain can achieve coordination via the revenue sharing contract.     

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。     

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.     

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。     

Effect of variable transportation and carbon emission in a three-echelon supply chain model

Several industries controls carbon emission during transporting products due to increased transportation for obtaining the best transportation way with reduced cost. This study considers a three-echelon supply chain model where the supplier makes semi-finished products and transports to manufacturer for finished products. The manufacturer transports products by single-setup-multi-delivery policy to multi-retailer. The aim of the model is to reduce the supply chain cost by considering variable transportation and carbon emission costs are considered due to several shipments. An algebraic approach is employed to obtain the closed-form solution. Numerical example, sensitivity analysis, and graphical representations are given to illustrate the model.     

Design and planning for green global supply chains under periodic review replenishment policies

We quantify the impact of jointly optimizing strategic network design and tactical inventory planning on the cost and CO₂ emissions of multi-echelon logistics networks. The obtained insights indicate that longer optimized replenishment cycles reduce a node’s transportation cost and CO₂ emissions but increase its inventory costs. Moreover, under a fixed replenishment cycle, a node’s service level increases when supplied by a satellite warehouse. Finally: (i) the costs of implementing optimal green network design decisions could be misleading if inventory planning is neglected, (ii) greening of supply chains could become expensive, (iii) current legislative CO₂ ton prices hardly influence logistics networks.     

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.     

An integrated model for stock replenishment and shipment scheduling under common carrier dispatch costs

We examine a joint inventory replenishment and shipment scheduling problem that arises in the context of a vendor-managed inventory (VMI) arrangement. Since a temporal shipment consolidation policy is being implemented, the inventory requirements at the vendor are affected by the timing and quantity of shipment release. The vendor’s problem is to determine an integrated policy for inventory replenishment and shipment release and to set its parameters. We develop analytical models for computing such integrated policies where it is economical to use common carriage for outbound transportation. We propose algorithmic approaches to set the optimal policy parameter values.     

Environmental determinants of VMI adoption: An exploratory analysis

This study empirically examines the determinants of adoption of Vendor Managed Inventory programs that have recently gained popularity in many industries. To achieve this goal, survey scales are adapted and developed for buyer and supplier market competitiveness, product demand, buyer operational uncertainty, and buyer–supplier cooperation. Based on the analysis of responses from purchasing managers in three industries, structural equation modeling results suggest that the competitiveness of the supplier’s market and buyer–supplier cooperation are positively associated with VMI adoption, while operational uncertainty for the buyer is negatively associated with VMI adoption. Managerial implications and limitations of the study are also noted.     

Analyzing the impact of intermodal-related risk to the design and management of biofuel supply chain

This study presents a mathematical model that designs a reliable multi-modal transportation network for a biofuel supply chain system, where intermodal hubs are subject to site-dependent probabilistic disruptions. The disruption probabilities of intermodal hubs are estimated by using a probabilistic model which is developed using real world data. We developed an accelerated Benders decomposition algorithm to solve this challenging NP-hard problem. Numerical analysis show that the model selects to use intermodal hubs located in areas with low disruption probabilities. In case of a disaster, the reliable solution results in 6.21% savings over the minimum cost solution.     

Modeling and optimizing transportation decisions in a manufacturing supply chain

We describe a transportation problem we studied at the trucking division of a textile manufacturer that owns and operates a large number of manufacturing facilities in all stages of the manufacturing supply chain. The problem involves scheduling of pickup and delivery of daily inventory movement between plants. We develop integer programming models that are based on the current workflow of the schedulers and that capture and optimize crucial aspects of the problem. We validate the models and demonstrate their use with actual data. The results suggest that an effective computerized decision-support system can be built around these models.