Developing a data base for planning— A shipping industry case

The shipping industry comprises many discrete sectors, with such widely differing characteristics of markets and vessel design that they are in effect separate industries. Planning therefore requires a detailed knowledge of each industry's characteristics—a data base from which future projections and corporate strategy can be developed.

International bulk shipping is not yet rigorously confined by intergovernmental agreements, except for regulations covering safety and technical standards, and it is therefore a market open to the economic forces of supply and demand. The market for parcel tankers, which carry a wide range of liquid cargoes in small quantities, is the subject of this study of how the supply and demand balance in a typical shipping industry is assessed.     

竞争环境下的轴-辐式集装箱海运网络设计问题

针对航运企业的重组与全球扩张引起的竞争问题,提出了竞争环境下的轴-辐式集装箱海运网络设计模型。模型采用基于路径的变量作为决策变量,利用离散函数来表示航运企业与航运联盟的竞争可吸引的流量(或客户),目的在于通过设计混合轴-辐式集装箱海运网络,实现以更低的服务成本和更短的服务时间最大化可吸引的流量,建立了枢纽港口数量约束、航线连接约束、航线中转约束、流量竞争约束等,运用多点交叉遗传算法进行求解,最后结合亚欧航线的集装箱海运市场进行实例分析,对考虑客户需求多样性与航运联盟对策下的轴-辐式集装箱海运网络进行设计,并验证了算法的计算效果。     

Managing High‐Tech Capacity Expansion via Reservation Contracts

We study capacity reservation contracts between a high‐tech manufacturer (supplier) and her OEM customer (buyer). The supplier and the buyer are partners who enter a ‘design‐win” agreement to develop the product, and who share the stochastic demand information. To encourage the supplier for more aggressive capacity expansion, the buyer reserves capacity upfront by paying a deductible fee. As capacity expansion demonstrates diseconomy of scale in this context, we assume convex capacity costs. We show that as the buyer's revenue margin decreases, the supplier faces a sequence of four profit scenarios with decreasing desirability. We examine the effects of market size and demand variability to the contract conditions. We propose two channel coordination contracts, and discuss how such contracts can be tailored for situations where the supplier has the option of not complying with the contract, and when the buyer's demand information is only partially updated during the supplier's capacity lead‐time.     

中国企业部门信用风险溢价期限结构与宏观经济因子

近年来，中国企业部门债务风险不断暴露，其是否会引发系统性信用危机正成为焦点。本文着眼于中国企业部门信用风险累积与暴露背后的宏观经济现实，在简约模型中引入结构向量自回归模型（SVAR），将经济冲击区分为总供给冲击、总需求冲击和货币政策冲击，以此研究各宏观经济因子对中国企业部门信用风险溢价期限结构的影响特征，从而揭示中国企业部门信用风险定价的宏观经济机理。本文发现，正向的总供给冲击和货币政策冲击有助于降低中国企业部门信用风险溢价，但正向的总需求冲击则会推高中国企业部门信用风险溢价，自2011年以来持续处于高位水平的信用风险溢价的主要根源正是4万亿经济刺激计划所带来的扩张性总需求，因此欲从根本上降低中国企业部门信用风险水平，应紧缩社会总需求，并通过制度改革和结构调整，改善社会总供给。     

Supply Chain Management of Fresh Products with Producer Transportation*

This article considers a class of fresh‐product supply chains in which products need to be transported by the upstream producer from a production base to a distant retail market. Due to high perishablility a portion of the products being shipped may decay during transportation, and therefore, become unsaleable. We consider a supply chain consisting of a single producer and a single distributor, and investigate two commonly adopted business models: (i) In the “pull” model, the distributor places an order, then the producer determines the shipping quantity, taking into account potential product decay during transportation, and transports the products to the destination market of the distributor; (ii) In the “push” model, the producer ships a batch of products to a distant wholesale market, and then the distributor purchases and resells to end customers. By considering a price‐sensitive end‐customer demand, we investigate the optimal decisions for supply chain members, including order quantity, shipping quantity, and retail price. Our research shows that both the producer and distributor (and thus the supply chain) will perform better if the pull model is adopted. To improve the supply chain performance, we propose a fixed inventory‐plus factor (FIPF) strategy, in which the producer announces a pre‐determined inventory‐plus factor and the distributor compensates the producer for any surplus inventory that would otherwise be wasted. We show that this strategy is a Pareto improvement over the pull and push models for both parties. Finally, numerical experiments are conducted, which reveal some interesting managerial insights on the comparison between different business models.     

Optimal Purchase and Transportation Cost Lot Sizing for a Single Item

A review of the literature indicates that the traditional approach for evaluating quantity discount offerings for purchased items has not adequately considered the effect that transportation costs may have on the optimal order quantity; despite the general fact that purchased materials must bear transportation charges. The transportation cost structure for less-than-truckload (LTL) shipments reflects sizable reductions in freight rates when the shipment size exceeds one of the nominal rate breakpoints. However, the shipper must also be aware of the opportunity to reduce total freight costs by artificially inflating the actual shipping weight to the next rate breakpoint, in order that a lower marginal tariff is achieved for the entire shipment. Such over-declared shipments result in an effective freight rate schedule that is characterized by constant fixed charge segments in addition to the nominal marginal rates. Over-declared shipments are economical when the shipment volume is less than the rate breakpoint, but greater than a cost indifference point between the two adjacent marginal rates. This paper presents a simple analytical procedure for finding the order quantity that minimizes total purchase costs which reflect both transportation economies and quantity discounts. After first solving for the series of indifference points that apply to a particular freight rate schedule, a total purchase cost expression is presented that properly accounts for the actual transportation cost structure. The optimal purchase order quantity will be one of the four following possibilities: (1) the valid economic order quantity (EOQ), QC; (2) a purchase price breakpoint in excess of QC; (3) a transportation rate breakpoint in excess of QC; and (4) a modified EOQ which provides an over-declared shipment in excess of QC. Finally, an algorithm which systematically explores these four possibilities is presented and illustrated with a numerical example.     

数据优势会使平台企业提高定价吗？——模型推导与理论分析

数字经济时代,数据成为平台企业的重要生产要素。本文分析了垄断环境与差异化竞争环境下,数据对平台企业定价行为的影响。研究结果表明：在垄断环境下,数据会降低平台企业产品或服务的价格;差异化竞争环境下,数据的丰富使市场中的平台企业可以自发地形成两种定价方式：对于为主流领域提供产品或服务的企业而言,数据会使其提高价格获取利润,而对于面临长尾需求的企业而言,数据会使其降低价格,采取"薄利多销"的手段获取利润。同时,本文也提出了对数据优势作用的进一步思考——数据有助于完全价格歧视的实现与产生新价格歧视场景;数据有助于企业识别自身特征,进一步使平台市场自发形成"主流层次"与"长尾层次"两个层次;数据有弱化市场势力的作用。     

人工智能、技术进步与低技能就业——基于中国制造业企业的实证研究

人工智能重塑中国制造业核心竞争力的同时，也加剧了行业内低技能型劳动力被取代的危机。本文以技术进步影响劳动力技能结构的理论机制为分析框架，聚焦人工智能与制造业的融合对低技能就业比重的因果效应。基于2011-2017年制造业企业的面板数据，首先将人工智能与制造业的融合定义为"AI产业化"和"产业AI化"，基于定义、逐家判断人工智能企业名单并定位人工智能的初始时间，再采用双重差分法围绕人工智能对低技能就业比重的因果效应及效应的传导机制展开实证分析。实证结果表明：（1）制造业企业融合人工智能显著降低了低技能的就业比重，即在一定程度上制造业内低技能潜在的就业机会被人工智能所挤出；（2）人工智能对低技能就业比重的负向效应具有动态异质性，即企业融合人工智能的时间越长，低技能就业比重下降的越多；（3）人工智能虽然通过刺激当期资本积累和收入扩张补偿了部分低技能就业比重的减少，但同时降低了低技能劳动力的相对边际产出，促使企业最终减少低技能员工的就业比重。     

Integrative Cycle Scheduling Approach for a Capacitated Flexible Assembly System*

This study revisits the traditional single stage, multi-item, capacitated lot-sizing problem (CLSP) with a new integrative focus on problem structuring. Unlike past research, we develop integrative cycle scheduling approaches which simultaneously address lot-sizing, capacity, and sequencing issues. Our purposes are to (1) explore the effect of sequencing on inventory levels, (2) examine the problem of infeasibility in the economic lot scheduling problem (ELSP), and (3) provide a simple methodology of generating low-cost cycle schedules in an environment with discrete shipping, dynamic demands, limited capacity, zero setup cost, and sequence-independent setup times. Our procedures are compared to benchmark cycle scheduling approaches in terms of both inventory cost and computation time under different demand scenarios, using the operating data from a flexible assembly system (FAS) at the Ford Motor Company's Sandusky, Ohio plant.     

Offshore Outsourcing,Yield Uncertainty,and Contingency Responses

In this article, we study an offshore outsourcing arrangement for a buyer of a produced good in the presence of supply yield uncertainty. We analyze the performance of contingency responses to the realized yield information at the end of production and prior to its delivery to the destination market. The contingency responses considered are: (i) Emergency Production via which an emergency order is placed with another fast and perfectly reliable offshore supplier; (ii) Emergency Production and Delivery via which an expedited shipping of (partial or total) good units is used on top of Emergency Production. Within a periodic review inventory system with uncertain demand setting, we theoretically characterize the optimal decisions on the cycle order size, the emergency order size, and the way to split the available good units between the fast and slow shipping modes. We provide comparative statics on how the choices of these quantities are affected by each other and by the demand and yield uncertainties. We use numerical examples to illustrate the values of such contingency responses and the impact of other factors on the cost of meeting demand.     

竞争环境下基于服务约束的轴-辐式海运网络优化研究

针对同一海运市场中不同的海运企业——领导者与跟随者在设计多分配的轴-辐式海运网络时引起的竞争问题,突破已往枢纽港口集合是给定的假设,将航线连接设计扩展为可存在多条,引入基于服务约束（服务质量\价格\时间）的吸引力模型来定量表示托运人的选择行为,建立了竞争环境下基于服务约束的轴-辐式海运网络优化问题的数学模型,利用NCP函数、凝聚函数和增广Lagrange乘子罚函数法对这一问题进行求解。算例仿真结果显示：（1）跟随者在托运人考虑单位服务价格时,即使不存在规模经济效应,跟随者也可通过建立合适的枢纽港口来获取一定的市场机会;（2）跟随者在存在较大规模经济效应时其利润最可观,因采用比例模型,在不存在规模经济效应下跟随者在领导者决定设计不同数量的枢纽港口时其利润不会统一收敛于某一定值;（3）跟随者在领导者仅设计1个枢纽港口时可通过建立大量的枢纽港口来争夺丰厚的利润,但对于港口集合 N={1,2,…,12} 的海运市场,领导者只需设计2个以上枢纽港口时跟随者的利润空间便会受到较大挤压。     

基于绿色投资效率的港航供应链投资策略研究

在IMO环境政策约束日趋严格的背景下，绿色投资成为港航企业提升自身竞争优势的方式之一。本文以港口主导的供应链为研究对象，分析三种投资场景与不同成员投资的利益关系，即从绿色技术投资效率对港航供应链的成本效应、绿色技术投入效应、经济效应和市场效应等方面展开分析，最后分析不同投资策略对消费者剩余和社会福利的影响。研究表明：港口绿色技术投资在一定程度上会增加整体供应链的成本投入；当绿色技术投资效率逐步提高时，绿色投入水平不断下降，降低了绿色投入的成本，从而达到“投入高效率，投入水平低增长，整体收益高增长”的投资效果；无论是承运人或是港口进行绿色技术投入，均会增加市场的服务价格，相较于非绿色技术投入，绿色技术投入时会增加整体市场的需求数量；从消费者剩余的角度考虑，承运人绿色技术投入相较于港口绿色技术投入产生的消费者剩余大，也会在一定程度上减少因价格“传递效应”带来的不利影响；从社会福利的角度考虑，虽然绿色投资可能会降低社会福利，但承运人投资产生的社会福利优于港口绿色投资时产生的社会福利；从保护环境的角度，政府的政策制定具有较高的优先级，有助于提升环境收益。研究结果进一步丰富了港航企业绿色投资的研究成果，可为合理权衡绿色技术投资效率，为港口供应链成员的绿色投资决策提供一定的参考，对绿色港口供应链的良性发展具有一定的指导意义。     

Demand Fluctuations in the Ready‐Mix Concrete Industry

I investigate the role of demand shocks in the ready‐mix concrete industry. Using Census data on more than 15,000 plants, I estimate a model of investment and entry in oligopolistic markets. These estimates are used to simulate the effect of eliminating short‐term local demand changes. A policy of smoothing the volatility of demand has a market expansion effect: The model predicts a 39% increase in the number of plants in the industry. Since bigger markets have both more plants and larger plants, a demand‐smoothing fiscal policy would increase the share of large plants by 20%. Finally, the policy of smoothing demand reduces entry and exit by 25%, but has no effect on the rate at which firms change their size.     

DEMAND MANAGEMENT: THE EVALUATION OF PRICE AND DUE DATE NEGOTIATION STRATEGIES USING SIMULATION

The research considers the problem of demand management in a firm where the firm's historical delivery service level reputation influences the number of quotation requests from its potential customers. Customers have a maximum and the firm has a minimum net price to due date tradeoff curve for each job. The demand management function bargains with the customer over price and promised due date. Bargaining finishes either with an agreed price and delivery date or with the customer refusing the firm's bid and placing the order elsewhere. The firm's objective is to maximize its long-term net revenue. The firm's demand management negotiation strategy guides this bidding process. The research demonstrates the use of simulation to test different demand management bidding and negotiation strategies for different market and firm scenarios. The demonstration uses 16 scenarios to test the different demand management negotiation strategies with a model of a classical job shop in a classical market. The investigation examines finite scheduling-based due date estimation methods, as well as the more traditional parameter-based methods. This demonstration shows that it is possible to test different bidding policies, using a simulation model of a firm and its customers, and to obtain usable results.     

制造企业服务化路径选择研究

服务化已经成为制造企业获取和保持竞争优势的重要途径，其本质是企业价值链的延伸，既包括投入服务化，又包括产出服务化。在实施服务化战略时，制造企业可以选择将投入、产出服务功能内部化或外部化，即自营或外包。从产品层面构建理论模型，比较研究制造企业的四种服务化路径：（1）外包投入服务和产出服务；（2）外包投入服务，自营产出服务；（3）自营投入服务，外包产出服务；（4）自营投入服务和产出服务。首先，通过分析需求质量弹性和质量成本系数、制造企业产品及服务的质量和价格、生产性服务企业服务的质量和价格以及制造企业与生产性服务企业的市场基础等模型变量，得到制造企业在每种服务化路径下的最大化利润。其次，通过比较每种路径下的最大化利润，得到路径选择的临界条件。最后，通过数值实验和算例分析，验证了模型的有效性和实用性。研究结果表明，何种路径成为更优的选择取决于制造企业的自身条件和所面临的市场环境。总体而言，在质量成本系数足够大于需求质量弹性的前提下，生产性服务企业所提供投入服务或产出服务的市场基础越大，将该种服务外部化的预期利润越高。研究结果将为制造企业的服务化路径选择提供理论依据和解决方案。     

Product mix in the TFT-LCD industry

As operational costs and equipment depreciation in the TFT-LCD (thin film transistor-liquid crystal display) industry are a high percentage of the total cost, most manufacturers usually fully utilise their production capacity to reduce the average unit cost. However, when the market demand is less than the supply the stock of panels increases; this forces manufacturers to instigate a price war to reduce levels of stock and results in a wide fluctuation in panel prices. Inventory stocks of panels could be decreased by optimising the product mix. This will help manufacturers to reduce the risk of holding stocks, increase profit, and improve competitive advantage. This study uses mixed integer linear programming (MILP) to construct a product mix for the TFT-LCD industry given the conditions of profit, productivity, raw materials supply, and market demand. A case study shows that this model is proven to be effective in generating product mix for the TFT-LCD industry while improving profit. The product mix generated by this model can provide a reference for the sales department for orders and shipping, for the production department for the order quantity, and for master production scheduling for each product.     

Shared planning: a new foundation for quality criteria.

The Chinese word for crisis has two characters. One for danger and one for opportunity. A crisis is a time for awakening to new perspectives and for asking different questions. The widely touted "liability crisis" in the health care field provides just such a time for new approaches. Perhaps there is a way to establish market mechanisms for decision making that gives expression to the desires and values of consumers while respecting the abilities and preferences of physicians. Quality might then be the result of natural selection or, more accurately, of market demand. Such a system would acknowledge that quality in medicine is not for defining. It's for having. Quality should be obtained in bargaining for services, not in mandates of professional regulation.     

基于产品安全责任的供应链激励与竞争策略

从产品安全责任入手,基于批发价格合同,运用博弈论的基本思想,对四种情景中供应链的均衡进行分析："非竞争与非激励协调"、"非竞争与激励协调"、"竞争与非激励协调"和"竞争与激励协调"。结果显示：适度的批发价格合同激励协调措施能够提升制造商履行产品安全责任水平、市场需求量、供应链及其各成员的期望收益,但过度激励会降低市场需求量与分销商的期望收益,进而阻滞供应链总期望收益的增加;竞争将降低市场需求量、供应链及其各成员的期望收益;低度激励时竞争将降低制造商履行产品安全责任水平,高度激励时竞争将提升制造商履行产品安全责任水平;供应链采用批发价格合同激励协调机制能够增强其对外部的竞争能力,但过度竞争将降低制造商履行产品安全责任水平,进而对供应链及其各成员的利益造成损害。研究成果对供应链的产品安全责任管理实践有重要的指导意义。     

竞争环境下客户服务投入对企业利润影响的均衡分析

客户服务投入是企业吸引新顾客和维持现有顾客的重要手段之一。然而,服务投入究竟是否能给企业带来价值？对于这一问题,业界和学界都没有明确的答案。本文通过建模的方法研究在竞争的市场环境下,固有的市场因素对客户服务投入价值的影响。研究发现,服务竞争的市场均衡结构是两家厂商都投入客户服务。服务投入给企业带来的价值随着产品差异度的提高而提高,随着厂商自身市场份额的增加而增加。即,在产品差异度高的市场,服务投入更容易给企业带来价值。而在集中度高的市场,服务投入更容易给市场份额大的企业带来价值。     

Maximizing the rate of return on the capital employed in shipping capacity renewal

Decisions regarding investments in capacity expansion/renewal require taking into account both the operating fitness and the financial performance of the investment. While several operating requirements have been considered in the operations research literature, the corresponding financial aspects have not received as much attention. We introduce a model for the renewal of shipping capacity which maximizes the Average Internal Rate of Return (AIRR). Maximizing the AIRR sets stricter return requirements on money expenditures than classic profit maximization models and may describe more closely shipping investors׳ preferences. The resulting nonlinear model is linearized to ease computation. Based on data from a shipping company we compare a profit maximization model with an AIRR maximization model. Results show that while maximizing profits results in aggressive expansions of the fleet, maximizing the return provides more balanced renewal strategies which may be preferable to most shipping investors.