装配系统中的供应商融资:银行贷款vs买方预付款

由多个供应商和一个装配商组成的装配系统中,装配商组装的最终产品需要由供应商提供零部件,不同供应商提供的零部件是互补的。供应商与装配商之间采用批发价格合同,由供应商决定批发价格而装配商决定订货量。供应商的资金是有限的,可能影响其供货能力以及装配系统的效率。供应商可以向银行借款或者由下游装配商提供预付款以缓解其资金约束的不利影响。针对银行贷款的情形,分析了装配系统的均衡订货量与批发价格,并通过图示直观地描述了资金约束对均衡订货量的影响。在装配商提供预付款时,若预付比例为外生变量,则供应商之间的博弈存在存策略纳什均衡,装配系统的绩效与预付比例以及供应商的资金有关;若预付比例是供应商的决策变量,则预付款可有效解决供应商的资金约束,相比于银行贷款,预付款的融资模式可使装配商和装配系统取得更高的利润。     

供应商风险规避情形下基于期权契约的组装供应链协调

基于产品分工的发展及供应链成员风险偏好不同的特性,构建了由多个风险规避的零部件供应商和一个组装商构成的两阶段组装供应链模型.首先,发现在各供应商均采用批发价格契约向组装商提供零部件情况下,各供应商的最优产量均小于集中决策下的最优产量;其次,引入期权契约机制对组装供应链进行了协调;最后,通过数值算例验证了期权契约协调机制的有效性.     

装配型企业订货量分配与订单排产联合决策研究

针对供应商交货数量不确定环境下,多品种小批量装配型制造企业因生产物料不配套造成生产计划不可行甚至客户订单拖期的问题,从企业运作整体出发,考虑订货量分配决策对订单生产和交货的影响,以最小化采购成本和最小化订单排产相关成本为优化目标,在允许零部件拖期交货且供应商提供拖期价格折扣条件下,建立订货量分配与订单排产联合优化模型。针对可行解空间巨大、传统数学规划方法难以求解的问题,从增强搜索性能角度出发,设计基于自定义邻域搜索算子的局部搜索机制和基于随机与种群重构变异机制的改进粒子群算法的模型求解策略。通过应用实例对本文模型和算法进行了有效性验证和灵敏度分析,结果表明,相比于传统的分散决策方案,本文模型能够有效降低整体成本水平,引入的改进机制能够显著提升算法搜索性能,为企业供应风险下的运营决策制定提供理论参考。     

考虑随机模糊缺陷率且允许缺货的EOQ模型

针对实际库存管理中的产品缺陷问题,研究了含随机模糊缺陷率且允许缺货的经济订购批量(EOQ)模型,并运用随机模糊理论将其转化为确定模型,设计了随机模糊模拟仿真算法进而确定了其最优订购策略.数值算例分析了缺陷率对最优订货量和最优利润的影响.     

供应量随机下基于VMI的两级装配系统协同模型

为降低供应商供应不确定的影响,研究了零部件供应量随机下基于VMI模式的两供应商-单制造商协同供货模型. VMI模式下,制造商确定协同契约,供应商确定零部件的生产量及供应量.提出了收益共享契约和基于剩余补贴与额外惩罚的收益共享契约两种协同机制,分析了其纳什均衡.研究结果表明,收益共享契约不能协调随机供应量的供应链;基于剩...     

大型客机零部件适航风险的贝叶斯网络推理研究

研究大型客机零部件适航风险的推理问题.基于适航取证中法规对飞机零部件适航的规定,研究了大型客机零部件适航的风险因素,建立了适航风险评价指标体系;构建了大型客机零部件适航风险推理的贝叶斯模型,采用区间数表征不确定的条件概率,结合云模型和模糊综合评价法确定先验概率;案例对某零部件适航的系统风险进行预测诊断.     

随机环境下考虑回收定价和销售定价的逆向供应链优化与协调研究

由再制造商和分销商组成的逆向供应链中,再制造商回收的废旧产品数量是与回收价格相关的随机变量,分销商面临的再制造产品需求是与销售价格相关的随机变量.再制造商决策回收价格并向分销商提供合同,分销商基于合同作出反应来决策订购数量和销售价格,目标是在随机回收和随机需求下最大化各自的期望利润.利用博弈论和优化理论,分别得到了分散式和集中式供应链系统下的最优决策,证明了分散式系统中的回收价格和再制造数量偏低而销售价格偏高,并提出了综合三种基本合同的供应链协调机制.最后通过数值仿真得到了系统参数对供应链决策和利润的影响.     

基于三支决策的灰色可能度聚类方法及应用

针对经典的灰色可能度聚类评估模型难以判定决策对象的灰类归属和过度聚类等问题,利用三支决策的思想和方法,通过引入三支灰类的概念描述决策对象和灰类之间的不确定聚类关系;将其代替灰色定权聚类中的灰类和严格的聚类关系,构建基于三支决策的灰色可能度聚类方法,并采用决策粗糙集中的贝叶斯推理确定聚类阈值;最后,以案例验证所提方法的有效性和合理性。结果表明：本文所构建的模型是经典灰色可能度聚类评估模型的拓展和泛化,可以有效避免过度聚类,降低决策风险,提高聚类可靠性。     

基于数量弹性契约的供应商数量选择问题研究

供应商数量对供应链的风险和成本有重要的影响,确定供应商数量必须考二方面因素。在引入数量弹性契约的基础上,考虑供应商的供应风险和市场需求的随机性,通过最大化供应链企业的收益,建立了最优供应商数量的整数规划模型;然后分析了数量弹性契约的可行性,衡量了最优供应商数量下存在的风险以及风险的影响程度;算例和仿真证明了模型的有效性。该模型在考虑供应风险、需求风险和供应成本的情况下选择最优的供应商数量,可以为供应链企业的供应商选择决策提供重要依据。     

随机中断和随机需求下闭环供应链最优回收定价模型

讨论了由一个制造商、一个零售商和一个第三方回收商组成的闭环供应链的差别定价问题.基于博弈论的理论和方法在集中式和分散式决策情形下分别建立了第三方回收定价模型,并给出了随机中断和随机需求下闭环供应链的最优定价策略组合,最后通过数值例子分析了供应中断对最优批发价和零售价的影响.     

Component ordering strategies in assembly systems with uncertain capacity and random yield

Sourcing components in a complex global supplier network may lead to a high degree of supply uncertainty. Events, such as unexpected production defects or insufficient supplier capacity, can cause unexpected shortages of required components and halt the assembly of final products. Accordingly, the assembly enterprises must effectively manage various supply uncertainties in their component ordering decisions to avoid such component shortfalls. These issues have guided this research to investigate the optimal ordering strategies of an assembler facing the following two types of supply uncertainty: the uncertain production capacity of a standard component (component 1) and the random production yield of a core component (component 2). The assembler makes the component ordering decisions before these supply uncertainties are realized. We characterize the optimal ordering decision and find that the assembler should order components 1 and 2 according to a fixed ratio, which only depends on the random yield of component 2 and the production cost of component 1, but not on the uncertain capacity of component 1. A case study is presented to further explore the intertwined effects of these two uncertainties in an assembly system. Finally, the model is extended to consider a secondary option of buying additional component 1 s after observing some or all of the supply uncertainties, and this secondary option endows the firm with different capabilities in counteracting the supply uncertainties.     

随机产出下考虑小微供应商成本利润率的供应链决策研究

小微型供应商由于产能、资金等限制,其目标可能是实现成本利润率最优,从而提高企业生存能力。基于该观察,区别于多数文献采用利润最优决策准则,本文研究由小微供应商和零售商组成的单周期供应链决策问题。小微供应商面临产出随机风险,以成本利润率最大为目标进行产能决策,零售商以利润最大为目标确定最优订购量。研究发现小微供应商的成本利润率受到自身成本偏重系数以及零售商盈利能力的共同影响,将出现亏损、合理盈利、超额盈利三种情况。并且,零售商采取不同订货策略也会对小微供应商盈利情况产生差异影响。保守(积极)订货策略下,零售商是否盈利取决于自身单位净利润能否弥补单位缺货损失(自身可盈利空间)。本文研究融合现实普遍存在的产出随机问题,为小微供应商和其他供应链成员的产能/订购决策问题提供有益的管理启示。     

Coordination of stocking decisions in an assemble-to-order environment

This paper examines an assemble-to-order environment involving a short-life-cycle product that is sold in two different configurations, each requiring a unique component that must be stocked in advance. Both configurations of the product are assembled on the same equipment which has limited capacity. The focus of the analysis is on the determination of the appropriate stocking quantities for each of the configuration specific components. Because the same assembly capacity is often reused for different instances of the component stocking problem, we treat assembly capacity as exogenous. This represents the fact that capacity decisions are often made less frequently than are procurement/production quantity decisions. We first solve for the first-best stocking policy when the components are produced internally. We then consider the case when the components are procured from external suppliers, and investigate how different forms of contract between the assembler and the component suppliers affect coordination of the supply chain as well as each party’s profit. One particularly interesting finding is that it is possible to coordinate the supply chain with a single-price contract between each supplier and the assembler while awarding all parties positive profit.     

带有随机订货点的两阶段报童模型

销售商可通过二次订货以达到降低风险、增加利润的目的,然而在实际中由于生厂商供货能力不足等不可控因素,销售商往往无法确定何时能进行第二次订货。针对这种现象,本文研究二次订货时间不确定的报童问题,假设随机订货时间点和需求率均服从均匀分布,建立了带有随机订货点的两阶段报童模型,给出了两阶段最优期望总订货量,使得零售商在整个销售期内的期望利润达到最大值。最后通过数值算例,对比分析了本文的二次订购模型与传统一次订购模型,研究结果指出在整个销售期内二次订货可以提高零售商的期望利润。     

Optimal pricing and inventory policies with reliable and random-yield suppliers: characterization and comparison

In this paper, we study the joint pricing and inventory replenishment problem for a periodic-review inventory system with random demand and dual suppliers, one of the suppliers is reliable but more expensive, the other supplier is less expensive but is unreliable with random yield. We characterize the firm’s optimal policies that simultaneously determine the optimal ordering and pricing decisions in each period over a finite planning horizon, and investigate the impacts of supply source diversification and supplier reliability on the firm and on its customers. We show that having source diversification or higher reliability of suppliers not only increases the firm’s expected profit, but also results in a lower optimal selling price, thus they benefit both the firm and its customers.     

The impact of decision timing on the suppliers’ interactions: simultaneous moves <Emphasis Type="Italic">versus</Emphasis> sequential moves

The last few decades have witnessed a huge growth of outsourcing in industry where the downstream firm assigns its production tasks to different upstream suppliers. This makes the supply chain structure more complicated and gives rise to some relevant operational questions. This paper focuses on a supply chain structure that consists of one assembler and two suppliers, and both suppliers’ production yields are stochastic. The assembler delegates the quantity decisions to the suppliers, and the two suppliers choose their production quantities either simultaneously or sequentially. We compare the suppliers’ equilibrium production strategies under these two scenarios. Our results show that the decision sequence can exert significant influences on the firm’s and channel’s equilibrium payoffs. At any given wholesale price, both suppliers produce more components under sequential moves than under simultaneous moves, and this results in higher payoffs for the suppliers, the assembler and the entire supply chain. The supplier’s profit increases if he can make the decision later under sequential moves. From the channel’s perspective, it is more beneficial for the supplier with a higher production cost to make the decision first. The assembler is able to extract more surplus by endogenously setting the wholesale price. However, this may make the suppliers worse off under sequential moves than under simultaneous moves.     

基于利润—CVaR的期权契约供应链协调

文章以一个风险厌恶销售商与风险中性供应商所组成的两级供应链为背景,以条件风险价值(CVaR)和期望利润的加权平均作为销售商的决策目标,对期权契约下销售商的订购策略及供应链协调问题进行了研究,并对比分析了销售商以CVaR为目标时的情形。在给出销售商在不同风险厌恶程度下的最优订购策略后,文章进一步给出了供应链相应的协调条件,并分析了此时期权权利金,销售商的风险厌恶程度和期望利润权重等参数对供销双方收益的影响,发现“利润-CVaR”法下销售商的风险厌恶程度对供销双方利润的影响与CVaR法下的情况有所不同,但权利金依然起到了分配整体供应链利润的作用,且销售商期望利润权重的增加会降低自身收益水平而提高供应商利润。最后,文章通过数值模拟的方式对上述结论进行了验证。     

Coordinating order quantity decisions in the supply chain contract under random demand

In this paper, we are concerned with the coordinating quantity decision problem in a supply chain contract. The supply chain contract is composed of one manufacturer and one retailer to meet the random demand of a single product with a short lifecycle. Our analysis show that the retailer expects to obtain higher profit under proper ordering policies, which can also maximize the expected profit of the supply chain. The manufacturer may induce the retailer to order the coordinated quantity by adjusting the unit return price. As a result, the supply chain is expected to achieve the optimal expected profit.     

The effect of supply uncertainty in price-setting newsvendor models

We consider a price-setting newsvendor model in which a firm needs to make joint inventory and pricing decisions before the selling season. The supply process is uncertain such that the received quantity is the product of the order quantity and a random yield rate. Two cost structures are investigated, the in-house production case in which the firm pays for the input quantity and the procurement case in which the firm pays for the quantity received only. Our objective is to investigate the effect of yield randomness on optimal decisions and expected profit. By using the theory of stochastic comparisons, we find that under both cost structures, a less variable yield rate leads to a lower optimal price and a higher expected profit. Moreover, we show that in the in-house production case, a stochastically larger yield rate also results in a lower optimal price and a higher profit, but this is not true in the procurement case. Examples show that the effect of supply uncertainty on optimal order quantity is not universal.