The Value of Production Schedule Integration in Supply Chains

This study explores the value of integrated production schedules for reducing the negative effects of schedule revisions in supply chains involving buyer and supplier firms. A stochastic cost model is developed to evaluate the total supply chain cost with integrated purchasing and scheduling policies. The model minimizes the costs associated with assembly rate adjustment, safety stock, and schedule changes for all supply chain members. Through experimentation, the paper examines the impact of several environmental factors on the value of schedule integration. This study finds that schedule integration can lead to overall cost savings in a supply chain, but some firms may have to absorb costs in excess of those they would incur with independent scheduling. Environments with high inventory holding costs and long supplier lead times may not find it beneficial to adopt an integrated schedule. Forecast effectiveness plays a critical role in realizing the benefits of schedule integration. The paper concludes with suggestions for future research.     

产能不确定供应商的风险厌恶行为对供应链的影响

针对具有产能不确定性的风险厌恶供应商和风险中性零售商组成的供应链系统,本文采用经典的风险指标Value-at-risk(VaR)衡量供应商的风险厌恶程度,并将其作为供应商的优化约束条件之一。在斯坦伯格顺序博弈的模型框架下,零售商做定价和订货量决策,供应商做批发价决策。本文求得供应商批发价在VaR约束下的理论上下界,研究了风险厌恶程度对最优批发价的影响。与风险中性环境下的结果相比,在设立合理目标利润的前提下,高风险厌恶程度可能使得供应商提高批发价,低风险厌恶程度则对供应商批发价无影响。当目标利润设立很高时,供应商为了逐利将会降低批发价诱导零售商提高订货量。     

Supply Chain Sourcing Under Asymmetric Information

We study a supply chain with two suppliers competing over a contract to supply components to a manufacturer. One of the suppliers is a big company for whom the manufacturer's business constitutes a small part of his business. The other supplier is a small company for whom the manufacturer's business constitutes a large portion of his business. We analyze the problem from the perspective of the big supplier and address the following questions: What is the optimal contracting strategy that the big supplier should follow? How does the information about the small supplier's production cost affect the profits and contracting decision? How does the existence of the small supplier affect profits? By studying various information scenarios regarding the small supplier's and the manufacturer's production cost, we show, for example, that the big supplier benefits when the small supplier keeps its production cost private. We quantify the value of information for the big supplier and the manufacturer. We also quantify the cost (value) of the alternative‐sourcing option for the big supplier (the manufacturer). We determine when an alternative‐sourcing option has more impact on profits than information. We conclude with extensions and numerical examples to shed light on how system parameters affect this supply chain.     

基于决策者风险规避特性的供应链需求信息共享价值分析

在随机需求条件下,利用条件风险估值(conditional value-at-risk,CVaR)的风险度量准则建立了供应链的需求信息共享决策模型,着重分析了零售商的风险规避程度以及市场需求的不确定性信息对供应链各决策者以及供应链整体信息共享价值的影响。研究结果表明,需求信息共享价值与零售商的风险规避程度、市场不确定性大小以及市场不确定信息所预测的市场需求变化情况有关。数值分析结果表明,零售商越害怕市场的不确定性风险,需求信息共享越有利于提升分散供应链的运作效率;但当市场信息反映出未来的市场需求是消极且零售商接近风险中性时,供应链的需求信息共享价值反而小于零,此时没有进行信息共享的必要。     

Integrated Order Scheduling and Packing

We consider an integrated production–distribution scheduling model in a make‐to‐order supply chain consisting of one supplier and one customer. The supplier receives a set of orders from the customer at the beginning of a planning horizon. The supplier needs to process all the orders at a single production line, pack the completed orders to form delivery batches, and deliver the batches to the customer. Each order has a weight, and the total weight of the orders packed in a batch must not exceed the capacity of the delivery batch. Each delivery batch incurs a fixed distribution cost. The problem is to find jointly a schedule for order processing and a way of packing completed orders to form delivery batches such that the total distribution cost (or equivalently, the number of delivery batches) is minimized subject to the constraint that a given customer service level is guaranteed. We consider two customer service constraints—meeting the given deadlines of the orders; or requiring the average delivery lead time of the orders to be within a given threshold. Several problems of the model with each of those constraints are considered. We clarify the complexity of each problem and develop fast heuristics for the NP‐hard problems and analyze their worst‐case performance bounds. Our computational results indicate that all the heuristics are capable of generating near optimal solutions quickly for the respective problems.     

工艺设计质量信息不对称环境下质量激励合同设计

工艺设计质量决定了产品可制造性，从而对产品质量产生重要影响。在生产外包环境下，不仅供应商的质量努力难以合同化，而且工艺设计质量可能是设计者的私人信息，因此在供应商和制造商之间往往是不对称的，从而为质量激励合同设计带来挑战。本文考虑一个制造商和一个供应商构成的两级供应链。制造商可能自己设计产品，然后将生产外包给供应商，也可能将设计和生产都外包给供应商。本文分析了在这两种外包策略下，制造商的质量激励合同设计。研究发现：1）当工艺设计质量是对称信息时，制造商可以通过质量合同设计实现全局最优质量和利润；2）当工艺设计质量是制造商的私人信息时，工艺设计质量高的制造商可以通过降低对供应商的质量惩罚强度以及增加采购价格来传递工艺设计质量的信号；3）当工艺设计质量是供应商的私人信息时，制造商可以通过质量合同菜单来甄别工艺设计质量信息。与工艺设计质量是对称信息时的均衡合同相比，在针对低工艺设计水平供应商的合同中，制造商降低质量惩罚强度和采购价格；在针对高工艺设计水平供应商的合同中，质量惩罚强度不变，但采购价格提高。     

Reexamining the Nurse Scheduling Problem: Staffing Ratios and Nursing Shortages*

Legislators at the state and national levels are addressing renewed concerns over the adequacy of hospital nurse staffing to provide quality care and ensure patient safety. At the same time, the well‐known nursing shortage remains an ongoing problem. To address these issues, we reexamine the nurse scheduling problem and consider how recent health care legislation impacts nursing workforce management decisions. Specifically, we develop a scheduling model and perform computational experiments to evaluate how mandatory nurse‐to‐patient ratios and other policies impact schedule cost and schedule desirability (from the nurses' perspective). Our primary findings include the following: (i) nurse wage costs can be highly nonlinear with respect to changes in mandatory nurse‐to‐patient ratios of the type being considered by legislators; (ii) the number of undesirable shifts can be substantially reduced without incurring additional wage cost; (iii) more desirable scheduling policies, such as assigning fewer weekends to each nurse, have only a small impact on wage cost; and (iv) complex policy statements involving both single‐period and multiperiod service levels can sometimes be relaxed while still obtaining good schedules that satisfy the nurse‐to‐patient ratio requirements. The findings in this article suggest that new directions for future nurse scheduling models, as it is likely that nurse‐to‐patient ratios and nursing shortages will remain a challenge for health care organizations for some time.     

考虑交货因素的热轧无缝钢管订单排程模型与算法

无缝钢管的市场需求具有多品种、小批量的特点，为了在满足客户需求的同时保证高效连续化生产，文章在满足生产工艺特征的基础上将配送地址和交货期等合同因素引入热轧无缝钢管订单排程问题中，建立了以适期交货、订单集中生产配送和最小化机器设备调整为优化目标的订单排程优化模型，并设计了两阶段求解算法：首先，以订单交货期与配送地址差异最小为目标，基于凝聚策略设计了订单聚类算法，将具有相同工艺约束、相似合同要求的订单进行聚类，并形成初始轧制计划；然后，以设备调整和提前/拖期最小为目标，设计混合变邻域搜索算法，对初始轧制批次进行排程优化。基于实际订单数据的实验结果表明，模型和算法对问题的描述和求解是可行有效的。     

Beyond Patient Classification: Using Individual Patient Characteristics in Appointment Scheduling

Scheduling patients involves a trade‐off between the productivity of the service provider and customer service. This study considers how outpatient medical facilities can improve their appointment scheduling by incorporating individual patient information in the scheduling process. Specifically, we obtain data on patient characteristics and examination durations from a health clinic, describe how that data can be used to predict patient examination durations in the clinic's appointment scheduling system, and evaluate the benefit of using individual patient characteristics over a conventional classification method. Computational results illustrate this method of patient scheduling reduces an overall cost function comprised of patient wait time, physician idle time, and over time by up to 24.2%, particularly when patients are sequenced with short duration patients being scheduled first. Several environmental characteristics are found to play critical roles in determining the magnitude of the benefit, including patient punctuality, no‐show probability, the clinic duration, the appointment rule used for scheduling, and the ratio of the physician's idle time cost to the patient wait cost. We also detail and evaluate a practical procedure for using heterogeneous scheduling under a fixed schedule.     

信息不对称下基于区块链驱动的供应链减排信息共享机制研究

信息不对称是阻碍供应链多主体协同减排的主要因素,针对消费者隐匿低碳偏好导致的供应链协同减排效率损失问题,通过与基于委托-代理理论的供应链减排信息甄别机制比较,设计了基于区块链驱动的供应链协同减排信息共享机制。研究表明,消费者获得额外的信息租金是导致供应链减排效率损失的主要因素,生产商和供应商通过分担一定比例的“区块链+协同减排”投资成本,可以获得额外的信息共享收益。“区块链+协同减排”信息共享机制在消除信息租金的同时,可以有效提高供应链收益,并且存在一最优收益分配比例使得生产商与供应商收益达到均衡以及供应链收益达到最优。“区块链+协同减排”信息共享机制可以有效提高供应链上下游企业协同减排效率,是推进我国“十四五”时期减排任务的重要路径之一。     

非对称信息下供应链应急管理和信息价值研究

研究了非对称信息下供应链在突发事件下的应急管理和信息价值问题。当供应链生产计划已经完成后,突发事件发生并导致零售商所面临的市场需求规模以及供应商的生产成本同时发生突变,而且这些突变信息对于供应链成员而言是非对称的。分析了非对称信息对应急管理的影响以及相应的管理对策,发现非对称信息下的最优生产量不超过对称信息下的最优生产量,导致供应链系统收益减少并产生了信息价值,分析了非对称信息下供应链系统的信息价值规律以及影响因素。最后给出数值算例说明了信息在供应链中的重要价值,同时也说明了突发事件情况下实施应急管理的必要性和重要性。     

信息非对称条件下的质量预防决策分析

研究了不同信息条件下供应链的质量预防问题,在文献[1,2]建立的有关质量签约问题的优化模型基础上,把供应商作为委托人和购买商作为代理人建立了供应链的质量预防决策委托代理模型。其中,质量预防水平和供应商要求购买商的前向支付是供应商的决策变量,质量评价水平是购买商的决策变量。本文重点研究了了非对称信息下供应链的质量预防和前向支付问题,考虑了购买商质量评价信息隐匿情况,运用极大值原理推导了供应商的质量预防和前向支付的最优解。最后结合一个农机公司拖拉机销售问题进行了仿真计算和分析,对比了不同信息环境下的决策结果。     

非对称信息供应链质量信号传递博弈分析

基于博弈论和委托代理理论,研究了非对称信息条件下供应链节点企业间如何进行质量信号传递的问题。供应商对生产过程投资水平进行决策并采取质量预防策略,为获得最优质量契约可将其生产过程水平类型以信号传递给生产商,其对接收到的中间部件或原材料进行质量评价决策和加工处理决策。运用最优化原理,构建了生产商产品质量决策控制模型,并对生产商支付的"信息租金"进行了量化的描述并进行了仿真检验,结果证明:供应商有激励性动机将其生产过程水平类型以信号传递给生产商,并提高中间部件或原材料质量水平;当生产商观测到供应商所提供的产品质量信号后,将降低其产品质量检验水平、提高加工处理水平,增加向供应商的前向支付,作为对供应商提高产品质量水平的质量奖励,同时整个供应链的联合期望收益将显著增加,并使生产商为获取供应商产品质量水平向其支付的"信息租金"减少。最后论证了供应商进行产品质量信号传递过程中"棘轮效应"的成因,并给出了以上各结论相应的定量分析与证明。     

Pricing and ordering decisions in a supply chain with downward substitution and imperfect process yield

We consider a manufacturer sourcing from two suppliers of asymmetric component quality and producing a quality-differentiated product, namely a low- and high-quality version, with each having deterministic demand. The manufacturer adopts the existing process to produce low-quality products with components from the supplier with low component quality, and develops a new process to produce high-quality products with components from the supplier with high component quality. The new process has imperfect yield, and products that do not meet the specifications for high-quality products can substitute for low-quality products produced with the existing process. We investigate the suppliers’ price decisions and the manufacturer’s ordering and production decisions in a game-theoretical model under dual sourcing. Our analyses reveal that increasing product differentiation or higher yield of high-quality products do not necessarily translate to a higher profit for the manufacturer. In light of the manufacturer’s sourcing strategies, we show that sourcing from a single supplier with high- and low-quality components yields a lower profit than sourcing from one supplier with high component quality and the other with low component quality. Finally, we investigate the manufacturer’s decision-making with endogenous yield rate of high-quality products. Our analyses demonstrate that the manufacturer benefits from setting the yield rate of high-quality products ahead of the suppliers’ price decisions.     

Lean Six Sigma applied to process performance and improvement model for the development of electric scooter water-cooling green motor assembly

Abstract

In response to the environmental issues triggered by global warming, worldwide companies gradually put the factor of carbon emission into the process of product lifecycle, developing green technology or adopting cleaner production aimed at sustainable development. Lean Six Sigma has advantages of cutting waste and facilitating process improvements as well as system analysis, helping enterprises create the overall business benefits in the value chain. Used in the renewable energy industry, it can promote the triple bottom line (TBL), the performance of sustainable production for corporate profit, social responsibility and environmental responsibility. Therefore, this work took the process performance of the electric scooter water-cooling green motor manufactured in Taiwan with the world’s highest density of scooters as a case study. The developed performance evaluation and improvement model for manufacturing scheduling and process quality achieved the goal of economic benefits of enhancing process quality performance by shortening manufacturing scheduling and reducing process variations with Lean Six Sigma. Besides, they could respond to the policy of energy saving and carbon reduction – replacing the traditional scooters of high-carbon emissions with the electric scooters of low emissions. Furthermore, they could bring enterprises into harmony with economic benefits, ecological benefits and social benefits.     

考虑策略型消费者的在线零售商库存信息披露及联合定价、库存决策模型

在两期销售环境下,研究了面向策略型消费者的在线零售商库存信息披露及联合定价、库存决策问题。考虑在线零售商库存信息共享和隐藏两种库存披露策略,构建了在线零售商两期销售利润模型。通过分析消费者的购买行为,讨论了在具有策略型消费者的市场中,在线零售商应如何选择库存信息披露策略,以及如何制定最优定价和库存决策。在此基础上,分析了相关参数对在线零售商决策及利润的影响。研究结果表明,在线零售商的最优定价及库存决策受消费者估值折扣系数和第二期定价策略的影响。特别地,当在线零售商选择第一期缺货时,更倾向于共享其库存水平信息;当在线零售商选择第二期缺货或者两期均不缺货时,消费者估值折扣系数存在一个阈值,当低于该阈值时,在线零售商会选择隐藏库存水平信息,当高于该阈值时,在线零售商会选择共享库存水平信息。     

Shop floor characteristics influencing the use of advanced planning and scheduling systems

The purpose of this article is to investigate how the manufacturing process, the shop type and the data quality, i.e. the shop floor characteristics, influence the use of advanced planning and scheduling (APS) systems in production activity and control (PAC). The methodology implemented is a multiple case study at three case companies. Each company has different shop floor characteristics, but all use a scheduling module in an APS system, which supports production scheduling. A theoretical framework is developed suggesting how APS system are used in the PAC activities, and which major aspect to consider. The case analysis shows that the scheduling module in APS system, foremost supports sequencing and dispatching. In particular, the shop type is influenced by the decision of how often the APS runs and what freedom is given to the shop floor. The manufacturing process influences how the dispatch list is created. Contrary to the literature presuming that APS systems are most suitable in job shop processes, it is found that the manufacturing process is not a crucial factor when deciding whether APS systems are an appropriate investment. It is found that the level of data quality needed in the APS system depends to a large extent on how the dispatch list is used. For example, is the dispatch list used as a guideline, not a regulation, the need for accurate data in the module is reduced. This article extends the previous literature concerning APS systems by analysing how APS systems influence PAC as a whole and increase the understanding of the challenges of using APS systems in PAC.     

An Experimental Comparison of Time-Based and Economic-Based Scheduling Methods to Maximize Net Present Value*

In the past, performance in dynamic-scheduling environments was primarily measured in terms of time or physical shop characteristics. Objectives such as mean tardiness, flow time, and work-in-process inventory were commonly used. Today, there is increasing interest in the use of more advanced economic performance measures. These measures have the more comprehensive objective of maximizing ownership wealth by economically scheduling jobs and tasks. This study presents a large-scale experiment testing time-based and economic-based scheduling methods in a dynamic job shop. These methods are evaluated on their ability to maximize net present value (NPV). The study considers the just-in-time (JIT) delivery environment. The job shop is hypothetical, but is based on models of real production situations. Results show that the use of very detailed economic information in a sophisticated manner generally improves economic performance. Where due dates are easy to achieve, however, time-based scheduling methods are at least as good as those based on economics. Also, where utilization is high and due dates tight, early cost information in release and dispatch is detrimental to schedule value.     

考虑供应商产品交付水平的供应链融资策略研究

供应商产品的交付水平直接影响下游制造商的生产，但是这种现象没有得到供应链金融研究的重视。为此，本文将供应商交付水平和供应链的运营融资问题结合起来研究。在考虑供应商产品交付水平的情况下，通过研究资金不足的供应商分别利用制造商预付款融资和风险投资方股权融资时，供应商的最优运营决策和融资策略，最后考虑了供应商对两种融资方式的选择。研究结果表明，供应商的自有资金水平对供应链均衡决策及其收益影响很大，有限的自有资金严重制约了供应商产品的交付水平，降低了供应链的运作效率；不管是资金充足，还是选择融资，供应商的利润不仅与自身的运营效率有关系，而且与替代供应商产品的批发价格有很大关系，当供应商的运营效率较低时，供应商的利润随着替代供应商产品的批发价格先增大后减小，当供应商运营效率较高时，供应商的利润随着替代供应商产品的批发价格逐渐增大。当供应商进行融资时，若自有资金水平较低，应通过股权融资的方式进行融资，若自有资金水平较高，供应商应该选择制造商预付款的方式进行融资，若自有资金量超过预付款融资时供应商所需资金的阈值时，供应商选择不融资。     

E-business services and business performance: a study of the telecommunications manufacturing industry

The development of information and communication technologies has significantly changed the business interactions as well as created new approaches for improving business performances. While the benefits from this development have been well documented in the literature, it also poses a significant challenge for companies in tracking or further improving e-business services. This article contributes to this body of knowledge by investigating the impact of e-business service dimensions on business performance in the telecommunications manufacturing industry. Based on 121 usable responses from a questionnaire survey of the UK telecommunication manufacturers, structural equation modelling is employed to identify the main e-business service dimensions which affect business performance significantly. The data analysis reveals that two e-business service dimensions significantly influence suppliers’ performance from the buyer's perspective. It also indicates the significant relationships between suppliers’ performance, buyer-perceived buyer–supplier relationship maintenance and the buyer's competitive advantage. The findings in this research not only help the supplier to understand which practices significantly improve its overall performance (as perceived by the buyer), but also assist the buyer in its supplier development efforts to improve its own business performance.