基于MSPC的物资采购风险控制研究

本文首先对大量物资采购危机案例进行归纳分析,然后对采购风险诱因进行分类总结。物资采购风险被划分为三类:企业物资采购市场风险、企业物资缺货与备货风险和供应链管理的物资采购风险。针对企业物资采购风险的整体性,本文提出了基于多变量统计过程控制(MSPC)的物资采购风险综合分析模型,该模型可从全局角度控制企业物资采购风险。最后结合一家典型铝业公司监测数据,论证多变量统计过程控制模型在控制企业物资采购风险方面的有效性。     

大庆油田物资采购及库存优化机制设计与模型研究

本文结合大庆油田物资采购中的实际问题, 考虑物资市场、需求、库存三方之间的不确定性和复杂性,分别讨论了物资采购价格时变、物资需求时变、以及不同仓储容量限制下的库存优化模型的研究进展。进一步,设计了针对大庆油田物资的采购及库存优化机制,并选取大庆油田实际采购中的4种A类物资,基于时间序列方法和0-1混合整数规划,分别对机制中的价格预测部分和策略优化部分进行了数值试算,结果表明,基于准确度较高的预测价格,运用混合0-1整数规划模型制定的多品种物资的最优联合采购策略,可以实现采购成本的节省,相比于4种物资2009年的实际采购成本,节约比率高达7.66%,同时价格预测的精度也得到了用户的认可。该机制为油田物资采购和库存优化管理项目中的辅助决策支持系统原型设计提供了参照。但考虑到大庆油田实际采购中的各种复杂因素的影响,还需进一步完善该优化机制,并对相关模型进行改进。     

三种物资同时段需求的EOQ模型

本文研究了三种物资同时段需求的EOQ模型,从理论以及实例均说明了该模型相对单一物资的EOQ模型,能够缩小这三种物资对仓库的占用空间,该模型在实际问题中要求需求和采购价格均随着时间的变化而变化,通过算法计算得到了满足三种物资同时段需求的最佳采购次数,最后得出了所要建立满足需求的最小仓库容量．     

考虑突发事件状态转移的政府应急物资采购定价模型

突发事件发生后,应急物资需求量呈现爆发式增长,政府首先将常规物资调拨至受灾区,并根据阶段性救灾成果作出应急物资采购决策。突发事件状态总是不断发生转移,使得政府已采购的物资在状态好转时容易造成浪费,在状态持续恶化时又不足以满足突发需求,因此考虑突发事件状态转移情形的应急物资采购定价策略对提升政府应急物资保障能力尤为关键。为此,本研究引入数量柔性契约到政府与应急物资供应商组成的两级应急物资采购供应链,构建了基于突发事件状态转移的应急物资采购定价模型,推导得出政企达成合作的条件与双方最优决策策略,并对比分析了契约合作与分散非合作下的供应商利润与政府成本。进一步采用数值计算与敏感性分析验证该模型的有效性,讨论了若干外生变量对政企最优决策与双方成本收益的影响,提出重要的管理启示。研究表明,考虑突发事件状态转移的基于数量柔性契约的政府应急物资采购定价模型既可以有效提高应急物资储备水平,又能保障供应商的合理收益以及控制政府成本,实现了政企双赢。     

油田A类物资采购决策支持系统研究

结合大庆油田物资公司在重要供应链管理环节,即采购、需求和库存中所面临的实际问题(物资需求增加、仓储压力增大、采购成本增多)及三者之间的相互作用,基于预测和优化理论,构建了针对油田A类物资的采购优化和库存管理决策支持系统原型,包括：预测模块、优化模块和方案调整评估模块,为相关部门制定合理物资采购方案提供决策支持.进一步,以银浪仓库中的4种A类物资为例,运用该原型系统进行数值模拟. 结果表明,2009年和2010年4种物资的总成本节省率分别为10.35%和8.07%,效益可观. 考虑到油田物资数据结构不完备及优化模型的复杂性,该原型系统在大庆油田大规模推广方面仍需进一步完善.     

大型水电工程物资调运建模及算法

根据小湾水电工程物资供应管理的实际情况,提出了物资调运的三级节点概念模型,论述了物资采购与调运的数学模型,并给出了具体算法。模型已应用于该工程物资调运决策支持系统中,运行实践表明,该模型能够辅助调度人员制定合理的物资采购与调运方案。     

突发事件下应急物资多目标优化调度模型与算法研究：以新冠肺炎疫情为例

突发事件下应急物资调度具有高度不确定性与动态性,应急物资跨区域调度计划能否科学合理制定对应急救援的有效开展具有重要影响。以武汉市新冠肺炎疫情为例,考虑应急物资跨区域调配的时效差异、地域分散以及资金消耗等要素,建立多周期下包含软硬需求时间窗约束的多物资品种、运输方式的跨区域三级动态物资调度网络模型,并设计一种带变异操作的动态变惯性权重自适应粒子群算法(VDCWPSO),利用疫情算例验证该算法的有效性和可行性。研究结果表明,在保障应急物资供应时效性、公平性、经济性原则下,物资跨区域调度可以缓解资源严重短缺状况、提高医用物资利用率,研究可为突发事件下应急物资调度计划的制定与动态调整提供决策支持。     

基于两类型灾害事件考虑的赈灾物资储备

赈灾物资的储备,既要符合物资的科学储存规律、又要满足物资储备的经济规律.在建立赈灾物资储备一般模型后,按照重复灾害事件和未遂灾害事件两类灾害事件的理论之说,对模型进行修改完善,分别构建未遂灾害事件的赈灾物资储备模型以及重复灾害事件的赈灾物资储备模型.通过实例分析,验证了所建模型的合理性和可行性.     

军需物资调集规划问题的研究

以军需物资调集为背景 ,在系统分析的基础上建立了全局优化问题的数学规划模型 ,并对模型求解进行了研究 ,提出两阶段规划算法 .仿真计算结果表明所建模型的有效性     

基于信息化技术的物资采购创新研究

物资采购是任何组织发展的中心环节,有效及时的物资采购直接影响着组织内部各种活动的正常开展。现代社会信息技术在物资采购领域的应用缩短了采购时间,提高了采购效率,推动了物资采购管理的创新。本文通过分析信息技术对物资采购的影响,为如何有效利用信息技术提出建议。     

Stochastic models of consumer behaviour

During the past thirty years much research has been carried out in order to produce decision aids for managers. Considerable efforts have been dedicated to models that describe how consumers make purchase decisions. Within this vast area of research we review stochastic approaches to consumer behaviour, i.e. probabilistic laws relating the observed strings of consecutive purchases to explanator variables. We start out by discussing the basic concepts underlying this field. Then we deal with models concentrating on brand choice, whereby we trace the development from the early ideas in the Fifties to today's sophisticated models. Subsequently we turn to the Negative Binomial Distribution, the ‘classical’ purchase incidence model, and its extensions. Then we describe combined purchase timing-brand selection models and introduce models of store choice and purchase quantity selection. After briefing on estimation and validation methods for stochastic models we finally critically review the state-of-the-art in this field. Special emphasis is placed on empirical applications throughout the review.     

批量购买下免费商品赠送对新产品扩散的影响

在非耐用品的购买过程中,批量购买的消费行为较为普遍。本文基于Bass模型,将批量购买看作一个扩散过程,建立批量购买下含免费商品的产品扩散模型;然后在扩散模型中引入重复购买和价格策略等因素的影响,构建了优化模型群。对不同购买方式下的免费商品赠送进行仿真分析,同时对模型中重要参数进行优化后分析,计算分析表明:和单量购买情形一致,当存在批量购买时,免费商品的赠送同样会加快产品的扩散速度,但值得赠送更多的免费商品以达到利润最大化。消费者的批量购买量越大,就越有必要赠送更多的免费商品来让消费者了解该产品,甚至对每个消费者发放免费商品。同时,通过对赠送时期的对比分析,发现只有在产品引入初期赠送最佳,形成了“首期赠送效应”。最后,给出了参数对免费商品赠送水平的影响范围与趋势。     

SAA-regularized methods for multiproduct price optimization under the pure characteristics demand model

Utility-based choice models are often used to determine a consumer’s purchase decision among a list of available products; to provide an estimate of product demands; and, when data on purchase decisions or market shares are available, to infer consumers’ preferences over observed product characteristics. These models also serve as a building block in modeling firms’ pricing and assortment optimization problems. We consider a firm’s multiproduct pricing problem, in which product demands are determined by a pure characteristics model. A sample average approximation (SAA) method is used to approximate the expected market share of products and the firm profit. We propose an SAA-regularized method for the multiproduct price optimization problem. We present convergence analysis and numerical examples to show the efficiency and the effectiveness of the proposed method.     

带有提前购买价格折扣的易逝品库存模型

经典Newsboy模型是在购买价格不变的情形下去确定最优进货批量．然而,对于一些具有特定的消费时间的商品（如中秋节的月饼等）,生产厂家为了更好地安排生产,通常提供提前购买价格折扣．这样确定何时进货、进多少货的问题对经销商来说就显得非常重要．本文研究了该问题,并建立了带有提前购买价格折扣的易逝品的一个库存模型,同时也给出了应用实例与参数的灵敏度分析．     

Integrated analytical hierarch process and mathematical programming to supplier selection problem with quantity discount

In this article an integration of analytical hierarchy process and non-linear integer and multi-objective programming under some constraints such as quantity discounts, capacity, and budget is applied to determine the best suppliers and to place the optimal order quantities among them. This integration-based multi-criteria decision making methodology takes into account both qualitative and quantitative factors in supplier selection. While the analytical hierarchy process matches item characteristics with supplier characteristics, non-linear integer programming model analytically determines the best suppliers and the optimal order quantities among the determined suppliers. The objectives of the mathematical models constructed are maximizing the total value of purchase (TVP), minimizing the total cost of purchase (TCP) or maximizing TVP and minimizing TCP simultaneously. In addition, several “what if” scenarios are facilitated and the quality of the resulting models is evaluated on real-life data.     

Management Adopts Operational Research: Session Report

Quantitative methods are derived to assist buyers purchasing commodities in fluctuating price markets. Demand is known whilst price is a stochastic variable which may contain trends or seasonal fluctuations. The essential feature of the problem is that the buyer has many opportunities to make a purchase.Mathematical models are formulated to describe particular commodity buying problems. The optimal purchasing policy is derived by using dynamic programming. It consists of a set of discrete price breaks at each buying opportunity together with the associated stock levels the buyer should aim to achieve at each price break with his purchase at this opportunity. The price breaks are dependent on the probability density functions of future prices and the number of future buying opportunities. Recurrence relations are derived to calculate these price breaks. The case of restrictions on the purchase quantity at each price offer, either because of supply limitations or by the buyer as a policy decision, and price discounts are also considered.A case study illustrating the techniques is given and the methods are extended to purchasing for a blending problem with substitutable commodities.     

基于承诺交货期的两阶通用件库存模型

在一个两阶段生产系统中,针对第二阶段应用单通用件的情况,引入承诺交货期因素,分别建立了第一阶段无通用件、单通用件、双通用件库存模型,考查了承诺交货期对通用件库存模型总成本的影响,分析了三类模型相应的最优库存水平。通过算例,说明了在一个第二阶段采用单通用件的两阶段生产系统中,当通用件与非通用件的单位采购成本相同时,并非第一阶段使用越多的通用件,总成本就越低。     

基于博弈的网络团购供应链信任协调机制研究

随着网络团购的快速发展,失信问题日益突出,此问题若得不到解决,将严重制约网络团购的发展规模.分析了影响供应链成员间信任的因素,并在运用KMRW声誉模型进行有限次重复博弈的基础上,引入第三方信用监管机构,设计了相应的约束机制和激励机制.分析结果显示,声誉模型对交易双方信任合作提供隐性激励,建立长期战略合作关系,有利于机会主义的守约行为;第三方信用监管机构的介入可以约束交易双方的机会主义行为,减少他们之间的信息不对称,能够最大限度的减少网络团购交易中的风险.     

Cost of ownership model for spare engines purchase for the Korean navy acquisition program

Major weapon system acquisition programmes often require high initial purchase cost which can be a burden for the procurement of a highly reliable system. In order to avoid the tendency of acquiring a less expensive weapon system with lower performance, a cost of ownership (COO) model can be applied to assess the lifetime cost of the weapon system. In many existing cost estimation models for weapon systems, the failure rate of the system is assumed to be constant and the functional relationship between the initial purchase cost and maintenance cost is not well defined. In this paper, we propose a revised COO model where random effects models are employed to accommodate the variations of the system failure frequency and repair time. It is expected that our model can contribute to the cost-effective procurement of spare engines for the Korean Navy acquisition programme within the limited national defence budget.     

The Effect of Payment Rules on Ordering and Stockholding in Purchasing

The payment conditions for the purchase of raw materials and components have received little attention in the literature on inventory control. A common practice is to require payment by some specific day of the month following the month of delivery rather than a fixed time period after delivery. Alternatively, for convenience, invoices for a particular supplier may always be dealt with on the same day of the month, regardless of the payment conditions. In such circumstances the classical square root E.O.Q. is not the ‘optimal’ size for purchase orders. Under the assumption of a roughly constant demand rate for the final products, as is assumed for lot sizing techniques in most statistical inventory control models, it is shown that orders should be specified as a number of integral months' demands. For those items whose annual purchase bill is over about £500 per year, the minimum cost purchase order should be one month's demand, to be delivered as early in the month as possible or in convenient sub-lots.This new model will not lead to large savings on the use of the E.O.Q. lot size. It is however claimed that this fits the practical situation better and avoids many of the nonsenses of the E.O.Q. of, for example, giving absurdly low order sizes for high priced items, and the need to place lower bounds on order sizes.