机场油料库存控制仿真研究

对机场油料库存水平进行计算机仿真分析是提高机场油料保障能力的重要手段,也是新时期实现精确后勤、节约后勤的有效途径。经过对油料库存系统的动态研究,分析了该离散事件系统的数学特性,通过仿真试验输出的系统性能评价指标,量化了库存水平的评价标准,为系统优化提供了决策依据。实际算例表明,将所开发的仿真程序应用于控制机场油料库存,能够形成合理的库存控制策略。     

两级系统多周期随机库存路径优化

库存和运输是物流活动的最主要环节,如何同时对二者进行优化,是供应商管理库存必须解决的核心问题。针对一个配送中心为多个零售商实施统一配送的两级系统,以最小化系统计划期平均总费用为目标,分析包括零售商存储费、缺货费,以及配送中心进货费、存储费和配送费的系统全部费用组成,整合库存与配送建立了库存路径问题数学模型。根据零售商需求的随机性和库存路径问题本身的两阶段性,估计零售商库存上下限,选择配送中心订货策略及配送优先原则,借鉴旅行商问题求解思路,设计了求解问题的启发式算法。用Matlab7.0编程实现仿真算例求解表明,整合优化比分别优化节省平均总费用6.2%。     

基于遗传算法的随机性（Q，r）库存系统仿真优化

（Q，r）模型是库存管理中的重要控制模型。对于随机性（Q，r）库存系统，难以用解析方法求解最优的库存控制策略。运用仿真优化技术，基于离散事件系统仿真原理，建立了随机性（Q，r）库存系统的仿真模型，设计了一种改进的遗传算法并应用它优化库存系统的库存控制策略。采用面向对象方法实现了仿真模型和改进的遗传算法。仿真实例表明所提出的仿真优化技术是可行且有效的。     

供应链中控制多级存储的射频辨识Push/Pull混合策略设计与仿真

由于射频辨识(radio frequency identification,RFID)激励的电子看板系统能够从远端看见供应链节点企业库存的状况,使得广域分布的供应链多级存储能够实现RFID激励的Pull控制.本文根据供应链分销网络多级存储的结构特点,以及系统运作期间各阶段节点企业的功能,在不同阶段采用不同的控制策略.因此,设计了多种不同的RFID激励的Push/Pull混合控制策略.为了比较和验证各混合策略对多级存储的控制性能,建立了以总库存成本、总缺货损失、总运行成本和库存周转率作为评价策略性能的指标体系.由于供应链系统的动态性与随机性,难以进行数学建模和精确求解,因此基于离散事件系统仿真原理,设计并实现了仿真模型.通过对各策略下多种结构的供应链分销网络多级存储的仿真,验证并分析了制造商阶段采用Push控制,分销商和零售商阶段采用Pull控制的策略的有效性和最优性.     

配送中心库存控制研究

制造业及销售业将没有竞争力的配送业务外包出去已成为企业的生存之道。配送中心的发展有效减少了交易次数和流通环节、产生规模效益、减少客户库存、提高库存保证程度、控制商品质量等。但配送中心较高的库存也使企业的运营成本居高不下,成为影响其发展的主要顽疾。本文在配送中心库存问题现状研究的基础上,提出配送中心库存控制方面存在的问题,最后,提出控制库存的方法、策略。     

考虑门店持有库存的同城整车配送优化模型

研究连锁零售企业配送中心和连锁门店构成的二级库存系统,考虑门店持有库存对配送中心库存的影响,以门店客户服务水平对系统总成本进行约束优化,建立了连锁零售配送中心同城整车配送库存优化模型,并给出了一个具体的的算例。     

物美的选择

2007年11月30日早8点，物美集团开始对自己的ERP系统进行切换。此次系统切换在云岗大卖场、古域店两家门面店，以及西红门配送中心、百子湾配送中心、家电配送三家配送中心同时进行。12月1日凌晨4点，原有系统中的库存数据全部导入到SAP的系统之中，在营运、配送中心、采购、IM、财务等部门的协同下，切换工作顺利完成。物美集团结算系统随即向供应商发出通知，上述两家门面店、     

基于RFID的配送中心管理系统设计与应用

传统的配送中心管理系统难以满足配送中心对信息实时采集、作业自动化管理的要求,而无线射频识别技术具有非接触式、多目标自动识别的技术优势.在成熟仓库管理系统的基础上,提出了基于无线射频识别技术的配送中心管理系统设计方案.简要介绍了系统的基本作业环节,包括货品入库业务、货品出库业务、库存盘点及补货等业务流程.基于一个实际系统的研发与实施案例,论述了系统开发和实施过程中所涉及的软、硬件技术难点与解决方案,最后总结并分析了该配送中心管理信息系统的实施成果.     

物流配送中心无线应用

随着技术的发展,目前大多数配送中心都有着一套先进的物流管理模式.对于一个配送中心信息化管理存在的问题主要是:库存信息的准确率较低,商品及库存信息不易追溯,较难实时查询控制的要求以及库存先进先出(FIFO)的控制问题.     

一种考虑相关需求的多级库存控制优化模型

在技术驱动的全球化市场,供应链管理已经成为企业和学者共同面对的重要课题。库存控制问题则是企业供应链管理中一个很重要的环节。该文研究了在供应链管理的环境下,由K个配送中心,每个配送中心由Nk个零售商组成的配送网络的库存控制问题。凭着对实际配送系统的观察和分析,在综合考虑了同一产品在不同零售点需求的相关性,以及同一产品在不同周期需求相关性的情况下,以最小化库存成本和运输成本之和为目标,一定的服务水平为约束,建立了多级库存控制优化模型。     

Assessing effect of global inventory planning with enterprise-wide information for a large manufacturer

This paper studies how a global manufacturer with many subsidiaries can achieve enhanced business value for the organization by sharing information within its supply chain network. Specifically, the uncertainties in the demands from the downstream distribution center affect the inventory levels at the upstream distribution center under different inventory policies, considering the uncertain lead times and the given order fill rates. With a generic simulation model and real data, we evaluate the magnitude of savings in inventory under the new inventory policy where information can be shared among subsidiaries, compared to the status quo where subsidiaries run independently with no information sharing. The results show that average inventory level at the upstream DC under the new policy would be reduced by approximately 3%. Considering the given manufacturer's global supply chain distribution network holds about $4 billion in average inventory, the 3% improvement is a very significant savings.     

A decision rule for coordination of inventory and transportation in a two-stage supply chain with alternative supply sources

This paper deals with a two-stage supply chain that consists of two distribution centers and two retailers. Each member of the supply chain uses a (Q,R) inventory policy, and incurs standard inventory holding and backlog costs, as well as ordering and transportation costs. The distribution centers replenish their inventory from an outside supplier, and the retailers replenish inventory from one of the two distribution centers. When a retailer is ready to replenish its inventory that retailer must decide whether it should replenish from the first or second distribution center. We develop a decision rule that minimizes the total expected cost associated with all outstanding orders at the time of order placement; the retailers then repeatedly use this decision rule as a heuristic. A simulation study which compares the proposed policy to three traditional ordering policies illustrates how the proposed policy performs under different conditions. The numerical analysis shows that, over a large set of scenarios, the proposed policy outperforms the other three policies on average.     

Joint shipment consolidation and inventory decisions in a two-stage distribution system

This study is motivated by a problem that an industrial distributorship faced while distributing automotive spare parts to service and repair centers. Considering the problem encountered, we present an analytical model for joint inventory and shipment consolidation decisions in a two-stage distribution system with a single distribution center, multiple non-identical retailers, and an outside supplier. The retailers face stochastic end-customer demand and use continuous review to replenish inventories. On the other hand, the distribution center uses a periodic review policy and employs a time-based shipment consolidation policy to dispatch retailers’ accumulated orders at the end of each consolidation cycle. We present an exact optimization technique to compute the optimal replenishment quantity at the distribution center, order-up-to level at retailers, and a shipment consolidation cycle length to measure the effects of inventory at retailers on the overall performance. Finally, we perform numerical experiments to measure the impact of various parameters on the overall distribution system.     

两级分销系统的订货策略研究

研究的两级分销库存系统由一个分销中心和N个零售商组成。在资源和能力有限的情况下,给定用户满足率,确定一个分销中心和多个零售商的最佳订货量,使得库存总费用最小。对库存建立费用模型,用改进的自适应遗传算法对其进行求解。     

基于多智能体的连锁零售多级库存集成与优化

针对连锁零售企业库存量高、库存成本高、配送断货和配送滞后等问题,建立基于多智能体系统的多级库存智能管理系统,应用NETLOGO平台实现多智能体库存优化系统的仿真研究。实验结果表明,该系统可以解决多级库存优化算法不符合实际情况或无法得到结果等问题,可应用于连锁零售多级库存优化和多智能体的建模仿真研究中。     

随机需求下的供应链库存控制策略研究

考虑了由多个供应商、一个配送中心组成的二级供应链系统在市场需求为随机情况下的多品种库存问题。通过确定各变量之间的关系,以配送中心损失期望值最小为目标函数,建立了一个混合整数非线性规划模型;利用求解多元函数条件极值的办法来求解该问题模型;最后给出了一个算例进一步诠释了该解法,从而丰富了在面对市场为随即需求下的多品种库存控制策略的研究工作。     

On the performance of binomial and beta-binomial models of demand forecasting for multiple slow-moving inventory items

The paper deals with the lead-time demand forecasting for inventory management of multiple slow-moving items in the case when the available demand history is very short. Two stochastic models of demand are compared: (i) the first based on the “population-averaged” binomial distribution of requests (the traditional approach); and (ii) the second based on the beta-binomial probability distribution that assumes that the demand probabilities for the inventory items follow the beta distribution, and employs the Bayesian framework to forecast the lead-time demand (longitudinal statistical approach). The conducted simulation study shows that using the latter model leads to the significant decrease of the holding cost and higher inventory system reliability. Besides, as follows from the simulation results, the beta-binomial demand model is especially useful when the demand probabilities are low and have the U-shaped distribution.     

需求随机依赖库存环境下的订货仿真优化模型

需求的随机性和依赖库存性是库存问题的特点之一,在需求以泊松分布的形式随机依赖库存的条件下讨论了（Q,T）型库存控制问题。为了评估库存控制策略的平均盈利水平,建立了该库存问题的离散事件系统仿真模型,设计了一种基于仿真的种群重叠、遗传操作非重叠的进化算法,用以优化库存控制策略,类似设计了基于仿真的模拟退火和粒子群优化算法进行比较。通过实例分析了不同参数的变化对模型最优解的影响,灵敏度分析表明需求依赖库存效应越明显时,利润水平越高,最优订货策略越倾向于高库存、短周期和现货销售。仿真实例说明了基于仿真的优化算法的可行性、有效性。     

Incorporating lateral transfers of vehicles and inventory into an integrated replenishment and routing plan for a three-echelon supply chain

This paper focuses on developing an integrated replenishment and routing plan that takes into account lateral transfers of both vehicles and inventory for a three-echelon supply chain system including a single plant, multiple distribution centers and multiple retailers. A mixed integer programming model to the overall system is formulated first, and then an optimization-based heuristic consisting of three major components is proposed. The purpose of the first component is to assign retailers to distribution centers, and determine routing schedules for each distribution center. And the remaining two components are corresponding to two smaller optimization models – a variant of the classical transportation problem modeled for determining vehicle transfer between distribution centers, and a variant of the conventional minimum cost network flow problem modeled for determining inventory replenishment and transfer. Experimental results reveal that the proposed algorithm is rather computational effectiveness, and the pooling strategy that considers both vehicles and inventory transfers is a worthy option in designing supply chain operations.     

A mathematical model to minimize the inventory and transportation costs in the logistics systems

In this paper we consider a logistics system for parts manufacturer distribution center(depot) to supply the parts to the parent company. And we formulate the mathematical model to minimize the sum of inventory holding costs at the depot, and the transportation and inventory costs at parts manufacturer.

We apply the model to an actual automobile parts manufacturer to demonstrate the effectiveness of the proposed model.