同步物流系统下准时化生产与配送调度问题研究

对于"加工-装配"行业而言,物流管理水平的高低直接决定了供应链绩效的好坏。本文以Supply Hub运作模式为背景,研究同步物流下装配系统中各节点的生产与配送调度问题。建立供应链各参与方的生产与配送模型,并通过规划求解得到供应商和制造商的最优生产周期、零部件的最优配送间隔以及零售商的最佳采购周期。最后,结合数值实验,对同步物流模式和传统物流模式下的供应链绩效进行了对比分析。研究结果表明:较之传统物流模式,基于同步化物流方式的装配系统总成本更低,这主要得益于库存成本的下降;由于采取拉动式的生产模式,因此同步物流系统下供应链中的生产和配送活动更加频繁;生产调整成本的增加提高了制造商的平均总成本,由此可见在同步物流系统下,供应商、制造商和零售商之间更需要相互协商和收益共享,从而实现多赢。     

基于库存分担策略的装配系统准时供货模型研究

本文考虑一个由多供应商和单制造商构成的装配系统。当市场的需求时间无法确定时,制造商通过对供应商设定合理的库存分担策略来降低自身成本,供应商则需要自行决定对制造商的补货时间并承担相应的库存持有成本和延迟惩罚成本。文章同时建立了供应商之间的纳什博弈模型和以制造商为主方的主从博弈模型,以找到供应商的最佳供货时间和制造商最优的库存承担时限。通过对比不同模式下供应链的整体绩效,找到实现供应链协调运作的必要条件,并通过数据分析进一步证明相关结论。     

不确定交货条件下两供应商-单制造商协同供货模型

研究了不确定交货条件下两供应商-单制造商系统基于惩罚策略的协同供货模型。首先建立了基于惩罚策略的供应商和制造商模型,接着对模型中供应商和制造商的最优决策进行了分析,得出两供应商的最优生产批量决策存在唯一纳什均衡,且最优期望利润间接地受其单位缺货成本的影响,而制造商最优订货批量大于等于市场需求。其次建立了集中决策下供应链利润函数模型,并证明了该函数是决策变量的联合凹函数,存在唯一的最优解。为了达到集中决策下的供应链利润最大化,推导出基于惩罚策略的供应链协同机制。制造商通过调整订货批量和零件单位缺货惩罚成本,在供应链利润最大化前提下获得最大的剩余利润。最后数例分析说明制造商如何通过控制该惩罚成本系数使得供应链协同并获得最大的剩余利润。     

基于时间惩罚的装配式建筑多源供应链协同模式研究

基于当前装配式建筑产业供应链的管理协同模式对于整体工程施工的工期及成本产生的影响,在供应商间信息不共享的二阶供应链系统模型中,研究不同维度下时间惩罚系数的设立对装配式建筑多源供应链的影响。从提高装配式建筑多源头供应链协同的角度,提出了时间强度惩罚模型,通过设置严重时间横向惩罚系数,激励供应商主动做出与供应链成本最优决策一致的交付决策,从而实现供应链最优供给。数值分析表明,在供应链中只有同时含一般时间惩罚和严重时间横向惩罚时,总承包方才能通过调节惩罚系数促使各供应商愿意选择与集中决策下供应链的最佳供货时间一致的到货时间,从而实现供应链的成本最小化。     

复杂产品主制造商-供应商协同合作最优成本分担激励研究

当前,“主制造商-供应商”的协同合作模式成为复杂产品的主流生产模式,与传统的制造商供应商合作激励相比,该合作模式更关注供应商的努力水平和长期战略合作,其努力程度决定了复杂产品的生产质量与效率。为激励供应商的努力合作,本文设计努力程度参数,提出了主制造商分摊供应商努力成本的激励策略,建立了基于努力程度的最优成本分摊模型,研究了Nash均衡和Stackelberg均衡两种结构下的激励模式,给出该激励模式下的主制造商分摊供应商研制成本的最优比例、最优努力水平和最优收益。研究结果表明,当供应商的努力程度大于等于努力阀值时,主制造商需分担供应商的努力成本,成本分担大小与供应商努力程度的平方成正比,且受单位收益系数和努力程度收益影响系数的影响。同时,研究表明,在主制造商供应商的协同合作机制中,主从关系的 Stackelberg博弈收益优于Nash均衡收益,应用分析进一步表明,主制造商通过分担供应商努力成本的激励措施可以有效地激励供应商的努力程度,实现在主制造商供应商利益均增长的情况下,达到帕累托改进。本文系统地揭示了主制造商激励供应商的最优成本分担问题,为复杂产品主制造商供应商的长期战略合作激励策略制定提供决策依据。     

供应链中具有产能限制的竞争企业中的信息共享研究

本文研究由一个供货商和两个制造商组成的二级供应链中，制造商之间的横向信息共享策略和供应商的定价问题。在模型中，上游供应商同时为下游两家制造商提供价格相同的原材料，下游制造商生产具有替代性的商品进行数量竞争，并受到相同的产能限制。以Cournot博弈为研究手段，求解了制造商的均衡订货决策和信息共享策略，分析比较了在不同的信息共享策略下制造商的利润、供应商的利润和批发价格。本文在研究制造商的信息共享策略时考虑了上游供应商的批发价格的影响。研究表明，当均衡解受到产能约束时，制造商的信息共享策略会反向。在某些情况下，完全信息共享和完全信息不共享都可能成为博弈的占优策略。上游供应商通过调整批发价格可以影响制造商的信息共享决策。该模型为上游供应商提供了一种最优定价策略，也为下游制造商提供了求解自身最优订货量和信息共享决策的方法。     

基于多重结算方式的装配系统协同问题研究

鉴于装配系统中存在的众多不确定因素,制造商往往采取延迟付款(货齐付款)的方式来降低供应商供货不同步的风险,而供应商则倾向于采用及时付款(货到付款).本文以装配系统为研究对象,分别针对延迟付款和及时付款方式建立了两供应商对单制造商的准时供货模型,考虑当每个零部件的供货提前期均不确定时,供应商和制造商应该如何进行相应的生产...     

VMI模式下供应商之间的生产进度信息共享研究

当制造商采用供应商管理库存策略时,供应商之间的生产进度信息共享一般能减少供应商的缺货和存货持有成本。针对供应商的生产提前期的不同情况,建立了供应商库存成本的优化模型。分析了供应商之间的生产提前期变动大小比较对供应商生产进度信息共享选择的影响,指出在绝大多数情形下生产进度信息共享是有利的,但在某些情形下共享不一定有利。无论信息共享与否,供应商中某一方存在的生产提前期的不确定都会增加供应商的最小期望成本,并对供应商如何实现期望成本最小提出了建议。     

嵌入Supply-hub的供应链联合生产与订货批量模型研究

考虑JIT环境下基于Supply-hub的供货模式,建立了制造商、Supply-hub和供应商的平均成本函数,提出了供应链分散决策和集中决策情形下的制造商和供应商的生产与订货批量模型。结果表明,制造商的生产批量在供应链分散决策时变化无规律,而在供应链集中决策时随着供应商与Supply-hub之间距离的增加而增加;相比分散决策,供应链集中决策时制造商的成本增加而供应商的成本减少,而整个供应链的总成本减少,供应商可以通过转移支付让制造商和供应商均受益,从而实现整个供应链的帕累托优化,随着供应商与Supply-hub之间的距离增加,协调能够让供应链得到更多的收益。     

基于激励相容契约的ATO式供应链交叉协调研究

考虑由两个零部件供应商与单个制造商组成的按订单装配式供应链中的信息不对称问题。以完全信息下各成员的利润作为基准,分析了成本类型信息占优的单个供应商"信息伪装"对纵向制造商和横向互补供应商所造成的损失,提出了基于激励相容的供应商-制造商纵向契约和横向互补供应商参与下的交叉协调契约。通过数学建模和仿真数据分析,研究表明：制造商主导的针对单个信息不对称供应商的激励契约,会产生"低端向下扭曲"现象,降低了横向供应商的最优订单量;制造商与横向的信息对称供应商分担信息租金而形成的交叉协调,在显示真实成本信息的同时,还可以提高最优订单量和整个供应链的全局利润。     

基于不同交货期策略的两供应商-单制造商协同供货模型

构建了基于不同交货期策略的两供应商-单制造商协同供货模型.在对基于交货窗的协议交货期交货策略1和基于费用分担的可控交货期交货策略2进行分析和描述后,根据策略1建立了交货窗下基于协议交货期的两供应商-单制造商的stackelberg对策模型,分析了各自的最优决策;根据策略2建立了费用分担机制下基于可控交货期的两供应商-单制造商协调优化模型,给出了求解最优值的算法.接着分析了策略2优于策略1下的交货期压缩费用分担系数,给出了分担系数的范围,在此基础上建立了基于改进理想点的不对称Nash协商交货期压缩费用分担协调策略.最后通过数例对两种交货策略进行了分析比较并验证了本文的分担协调策略是有效的.     

Outsourcing Competition and Information Sharing with Asymmetrically Informed Suppliers

This paper studies an outsourcing problem where two service providers (suppliers) compete for the service contract from a client. The suppliers face uncertain cost for providing the service because they do not have perfect information about the client's type. The suppliers receive differential private signals about the client type and thus compete under asymmetric information. We first characterize the equilibrium of the supplier competition. Then we investigate two of the client's information sharing decisions. It is shown that less information asymmetry between the suppliers may dampen their competition. Therefore, the client does not necessarily have the incentive to reduce information asymmetry between the suppliers. We characterize the conditions under which leveling the informational ground is beneficial to the client. We also find that under the presence of information asymmetry (e.g., when the suppliers have different learning abilities), sharing more information with both suppliers may enhance the advantage of one supplier over the other and at the same time increase the upper bound of the suppliers' quotes in equilibrium. Consequently, the suppliers compete less aggressively and the client's payoff decreases in the amount of shared information. The findings from this study provide useful managerial implications on information management for outsourcing firms.     

Using Frontier Portfolios to Improve Make‐to‐Order Operations

Make‐to‐order (MTO) manufacturers face a common problem of maintaining a desired service level for delivery at a reasonable cost while dealing with irregular customer orders. This research considers a MTO manufacturer who produces a product consisting of several custom parts to be ordered from multiple suppliers. We develop procedures to allocate orders to each supplier for each custom part and calculate the associated replenishment cost as well as the probability of meeting the delivery date, based on the suppliers' jobs on hand, availability, process speed, and defective rate. For a given delivery due date, a frontier of service level and a replenishment cost frontier are created to provide a range of options to meet customer requirements. This method can be further extended to the case when the delivery due date is not fixed and the manufacturer must “crash” its delivery time to compete for customers.     

Capacity Sharing and Cost Allocation among Independent Firms with Congestion

We analyze the benefit of production/service capacity sharing for a set of independent firms. Firms have the choice of either operating their own production/service facilities or investing in a facility that is shared. Facilities are modeled as queueing systems with finite service rates. Firms decide on capacity levels (the service rate) to minimize delay costs and capacity investment costs possibly subject to service‐level constraints on delay. If firms decide to operate a shared facility they must also decide on a scheme for sharing the capacity cost. We formulate the problem as a cooperative game and identify settings under which capacity sharing is beneficial and there is a cost allocation that is in the core under either the first‐come, first‐served policy or an optimal priority policy. We show that capacity sharing may not be beneficial in settings where firms have heterogeneous work contents and service variabilities. In such cases, we specify conditions under which capacity sharing may still be beneficial for a subset of the firms.     

How does information sharing affect first-tier suppliers’ flexibility? Evidence from the automotive industry in Sweden

This study addresses the critical research issue of how supplier delivery performance can be enhanced by integrating information sharing into volume and delivery flexibility. This study developed a research model to relate information sharing on demand forecasts and inventory data between original equipment manufacturers (OEMs) and first-tier suppliers. Based on a sample of 52 suppliers from automotive industry in Sweden, partial least squares structural equations modelling (PLS-SEM) was used to assess the model. The results confirm that sharing demand forecasts is a key enabler of supplier volume and delivery flexibility while sharing inventory data is not. The study contributes to enlarging the knowledge about supply chain management from the suppliers’ perspective. It also contributes to knowledge by validating the conceptual model and operationalisation of constructs. The study also has practical contribution in which management should focus on improving communication and collaboration practices with OEMs for effective sharing of demand forecasts.     

The Impact of Forecast Errors on Early Order Commitment in a Supply Chain*

Supply chain partnership involves mutual commitments among participating firms. One example is early order commitment, wherein a retailer commits to purchase a fixed‐order quantity and delivery time from a supplier before the real need takes place. This paper explores the value of practicing early order commitment in the supply chain. We investigate the complex interactions between early order commitment and forecast errors by simulating a supply chain with one capacitated supplier and multiple retailers under demand uncertainty. We found that practicing early order commitment can generate significant savings in the supply chain, but the benefits are only valid within a range of order commitment periods. Different components of forecast errors have different cost implications to the supplier and the retailers. The presence of trend in the demand increases the total supply chain cost, but makes early order commitment more appealing. The more retailers sharing the same supplier, the more valuable for the supply chain to practice early order commitment. Except in cases where little capacity cushion is available, our findings are relatively consistent in the environments where cost structure, number of retailers, capacity utilization, and capacity policy are varied.     

Sourcing Through Auctions and Audits

Buyers often find that obtaining complete information about suppliers is costly. In such scenarios, there is a trade‐off between the costs of obtaining information and the benefits that accrue to the owners of such information. There are also various ways in which the missing information can be obtained or inferred. In this paper, we compare the efficiency of obtaining information via the classical mechanism design approach, which relies on the information available before the contracts are designed, with that of an “audit‐based” approach, which relies on the information obtained after the fact. In our model, a single buyer (the Stackelberg leader) wishes to procure a package of products or services from various competing suppliers that possess private cost information. We allow for arbitrary cost and revenue functions and can incorporate multiple cost and revenue drivers. We show how the buyer can optimize her profit and at the same time coordinate the channel by using a contract scheme involving auctions, audits, and profit sharing. We also examine the behavior of this mechanism when the supplier can exert effort to reduce cost but the cost of effort cannot be verified. We propose several mechanisms for different precontract informational scenarios and compare their performance.     

产品后市场服务渠道选择:垂直式或网络化?

制造业服务化让企业将核心业务向服务领域延伸.在运营成本和服务能力的约束下, 为了给顾客提供高水平服务, 后市场服务可以由供应商自主提供, 或由第三方服务商提供, 由此分别形成了垂直式渠道和网络化渠道.针对这两种供应链渠道分别进行了建模优化, 通过对比两种供应链结构下的渠道服务水平、市场供给量和供应链上各成员的利润, 讨论了供应链的最优渠道结构选择.研究结果表明, 只要服务成本不变, 供应链的渠道结构不会改变服务水平.供应链最优的渠道结构由供应商与第三方服务商的服务成本差异决定, 只要第三方服务商的服务成本足够低, 供应商就应该选择服务外包和网络化渠道, 从而实现帕累托改进.     

考虑保鲜努力与增值服务的生鲜电商供应链最优决策与协调

针对一个生鲜电商与一个生鲜供应商组成的供应链，其中生鲜电商负责销售农产品并提供增值服务，而生鲜供应商负责农产品的保鲜配送。考虑保鲜努力与服务水平均会影响生鲜农产品的市场需求，通过构建集中式与分散式下的生鲜电商供应链决策模型，分析了新鲜度需求弹性、服务需求弹性等因素对最优决策的影响，并对比分析了分散式与集中式决策下的最优决策。在此基础上，设计了"收益共享-双向成本分担"契约，通过合理设计契约参数实现了生鲜电商供应链的完美协调与帕累托改进。最后，进一步深入分析了供应链在协调前后的最优决策变化，并用数值算例进行了考察与验证。研究发现：供应链在协调后必然会提高产品新鲜度与服务水平，但可能会导致更低或更高的生鲜农产品销售价格。当新鲜度需求弹性与服务需求弹性较低时，生鲜电商在协调后会制定相对更低的产品价格，实施"优质低价"策略；而在新鲜度需求弹性或服务需求弹性高于某一水平时，生鲜电商在协调后会制定相对更高的产品价格，实施"优质优价"策略。