基于可靠性增长的产品保修期优化设计系统动力学模型

为分析保修期对企业经营绩效的影响,使企业更科学合理地制定保修期,从技术和营销两个维度,对保修策略与企业经营绩效影响因素二者之间的相互关系进行了研究,并考虑研发和生产过程中持续质量改进的影响,建立了基于可靠性增长的保修期优化设计系统动力学模型,并将该模型应用于某空调企业的仿真分析。应用分析结果揭示:在产品可靠性增长的情况下,企业每年的预提保修成本先增加后减少;当产品的可靠性水平增长达到某一阈值时,应采用适当延长保修期的策略来实现企业利润的最大化。     

基于多目标优化的绿色供应链博弈模型及利润共享契约

为研究环境效益对绿色供应链最优决策的影响,基于多目标优化与博弈理论,构建了制造商同时考虑利润与环境双目标下的供应链博弈模型,分析了集中式与制造商主导Stackelberg博弈模式下的供应链决策,并进一步建立了利润共享契约下的博弈模型,对以上3种均衡结果进行比较。研究表明,制造商考虑环境效益目标会使自身利润减少,零售商利润、产品绿色度与环境效益相应提高,整体供应链利润先增大后减少;而利润共享契约能够实现产品绿色度、环境效益以及供应链各成员间利润的多重协调。     

考虑保修服务的制造/再制造融合产品优化配置研究

为了解决制造与再制造融合产品配置以及客户对于再制造产品零部件信心不足等问题,从产品保修服务出发,根据故障率确立多种保修模块的保修期和成本,同时结合公理设计和模糊矩阵方法,对制造与再制造融合产品进行模块划分,构建多种保修模块下的产品模块化配置方案。以产品保修利润、产品成本、绿色环保度为目标函数,建立多目标优化模型,采用遗传算法进行求解,得到考虑保修服务的制造与再制造产品优化配置方案。最后,以某公司考虑保修服务的制造与再制造汽车产品配置为例,验证了上述方法可行性。     

可靠性费用与现场修理费用的关系

顾客使用产品时所发生的故障次数是对产品可靠性最严峻的考验。任何使产品报废或难以使用的故障都会引起用户的不满并要求予以修理(如在保修期内)。在保修期内的修理证明费用高昂。而且这种支出与产品的可靠性和可保养性成反比。我们常常通过直感来判断提高产品可靠性应花费多少,可是降低保修期的修理费用可以弥补提高可靠性所花的额外支出。当然,其它无形的方面——如公司质量声誉和顾客     

产品族配置与考虑升级的再制造设计主从关联优化

针对产品族配置与考虑升级的再制造设计协同问题,提出一种主从关联优化方法,建立了一个双层规划模型.该模型以产品族配置设计为主优化问题(主者),并以产品族的全生命周期利润最大化为目标建立上层模型;下层优化问题则是以再制造利润最大化为目标,决策如何选择产品的升级模块和再制造模块(从者).为了求解该模型,开发双层嵌套遗传算法及其相应的编码策略.最后,将该模型和求解算法应用于台式电脑产品族案例中,将所得的结果与两阶段方法进行比较,验证了其有效性及可行性,并说明了所提主从关联优化方法在解决产品族配置与考虑升级的再制造设计关联优化问题方面的优势性.     

基于动态优选元胞遗传模糊聚类的使用可靠性区域粒度确定方法

为了进行使用可靠性区域粒度划分研究,在分析空调使用可靠性影响因素的基础上,以其使用可靠性同类区域差异最小为目标,建立了使用可靠性基于工作环境和用户使用习惯两类影响因素的多变量高维聚类模型,提出求解该模型的一种动态优选元胞遗传模糊聚类算法。该算法在经典元胞遗传算法和模糊C-均值算法的基础上引入信息熵理论和优选策略,并采用动态交叉和两阶段变异算子,因此集成了模糊C-均值收敛速度快和元胞遗传算法在解决复杂问题时多样性好、全局搜索能力强的特点。通过6个标准测试数据集的测试结果,证明新算法相对于模糊C-均值、遗传模糊聚类算法和粒子群模糊聚类算法具有更高的聚类精度和稳定性,尤其适合处理高维复杂数据的聚类问题。最后运用该算法求解模型,并评价不同粒度层次下聚类结果的有效性,进而确定使用可靠性最优区域粒度划分方案,表明算法能有效解决相关的实际工程问题。     

常规产品与新产品的预售与回购策略比较研究

为了鼓励消费者选择预购短生命周期产品,针对常规产品和新产品两类产品分别构建了经销商预售回购联合策略模型,并对两类产品的预售价格、回购价格和产量优化决策进行了对比研究,得出以下结论:在常规产品的预售问题中,消费者自身消费心理的变化是常见的退货原因,此时折价回购可使零售商的利润最高;在新产品的预售问题中,消费者往往因产品不符合预期而退货,回购策略会提高需求的不确定性、增加订货决策的难度,此时回购对零售商不利。     

供求不确定下的通用零部件供应商协同研究EI北大核心CSCD

针对供应链中零部件供应和产品需求的不确定性,构建了通用零部件供应商与多个专用零部件供应商之间的横向协同供应机制。考虑了专用零部件分散决策、通用零部件分散决策和通用零部件协同供应三种模型,通过数学推导和Monte Carlo模拟仿真,比较了三种模型的最优期望利润及差异。结果显示:协同供应能够减少或消除核心制造商的库存成本浪费、提高利润,但协同的价值和效果明显依赖于协同努力成本。     

不同制定者以旧换新策略下的产品绿色度与定价

为提高产品绿色度水平,促进废旧产品循环再造,考虑企业自主推行以旧换新策略,基于制造商实施产品绿色化设计战略,构建了无以旧换新、制造商自主以旧换新、零售商自主以旧换新3种二级供应链决策模型,分析了3种模型下制造商产品绿色度水平、产品市场零售价格、旧产品返利价格的最优决策。通过数值仿真,对3种模型下产品价格、产品需求和企业利润进行了比较分析,并讨论了老顾客市场占比率、旧产品折旧度对企业最优利润的影响。研究表明,产品价格在零售商以旧换新策略下最高,产品需求在制造商以旧换新策略下最高;制造商利润在制造商以旧换新策略下最大;零售商最大利润依赖于产品绿色度水平、老顾客市场占比率和旧产品折旧度,当它们分别低于某阈值时,零售商利润在制造商以旧换新策略下最大,当它们分别高于该阈值时,零售商利润在零售商以旧换新策略下最大。     

不确定交货时间下基于BOM下线结算的供应链协同供货

构建了交货时间不确定且需求价格时间敏感下基于物料清单下线结算的两供应商—单制造商协同供货模型。在对问题进行相关描述和假设后,分析了不考虑协同供货的供应链收益决策模型,并对供应商和制造商的最优决策进行了分析,然后对考虑协同供货的供应链收益模型进行了分析并推导出最优解的性质。数例分析比较了不考虑协同供货和考虑协同供货两种决策模式下的供应链收益和最优解的差异。结果表明,考虑协同供货决策的供应链收益要明显大于不考虑协同供货决策的供应链收益,而考虑协同供货决策下制造商的产品最优销售价格和供应商的最优协议提前期均小于不考虑协同决策。     

Joint determination of price and upgrade level for a warranted second-hand product

An upgrade action is a pre-sale procedure that brings the second-hand item to an improved functional state and effectively reduces its age. This action is usually costly and adds directly to the sale price of the second-hand product, but it improves the product reliability and can reduce the warranty servicing cost. In the present paper, we propose a decision model to determine the optimal price and upgrade strategy of a warranted second-hand product to maximize the dealer's expected profit. The objective function includes both demand and cost functions, where purchase price from an end user, upgrade cost, and warranty cost are involved. We illustrate our finding using real data on second-hand electric device. Also, a sensitivity analysis is conducted to evaluate the effect of model parameters on the optimal solution.     

Impact of reliability on warranty: A study of application in a large size company of electronics industry

This paper presents product reliability on component basis and investigates the possible effects on warranty which constitutes a non-technical issue. Product reliability is a key factor, which is used in considering the warranty period. It plays a significant role that a mistake in warranty forecasting could cost a lot for companies. The objective is to empirically examine the nature of general reliability of manufactured goods and conduct a case study in an electronics company. In this regard, reliability will be stated from the actual manufacturing point of view. A case study was applied in manufacturing industry. LCD TVs were undertaken to follow. To test reliability, a parametric Weibull model was used and hazard rates of products were estimated with linear regression method. For this research work, the lifetime data obtained by service departments, censored both left and right. Data were used in MINITAB14 to produce the reliability results of the LCDs to reveal the relationship between product reliability and product warranty in the consumer electronics industry. In this manner, this paper would help the company to decide whether it is favorable to extend the warranty period based on the failure findings.     

Optimal pro-rata warranty decision with consideration of the marketing strategy under insufficient historical reliability data

Warranties play an important role in the market, not only safeguarding the rights and interests of consumers, but also promoting the sales and reputation of manufacturers. Due to their impacts on the market, manufacturers should take their warranty policies into consideration in developing an integrated marketing strategy which can promote a product by simultaneously considering pricing, production, and related post-sale services. Most of the studies regarding the issue of pro-rata warranties (PRW) only focus on cost analysis with the reliability estimation, and few consider how marketing strategies can be integrated in the warranty decision. Moreover, the manufacturer may not have sufficient historical data to estimate the deterioration of a newly developed product, and therefore, the results obtained from analytical models may not be reliable. A Bayesian analysis should be a reasonable approach in order to deal with such a problem for the situation of insufficient historical data because it can effectively assess the deterioration based on experts’ opinions and possibly few relevant data. Accordingly, this paper proposes a Bayesian decision-making model which considers the PRW policy with the pricing and the production strategy. Moreover, in order to deal with the complexity of computation of the proposed model, a heuristic algorithm is also provided, and finally, a practical application case is used to demonstrate its usefulness.     

Setting Single-Period Optimal Capacity Levels and Prices for Substitutable Products

In this paper, we consider how a company that has the flexibility to produce two substitutable products would determine optimal capacity levels and prices for these products in a single-period problem. We first consider the case where the firm is a price taker but can determine optimal capacity levels for both products. We then consider the case where the firm can set the price for one product and the optimal capacity level for the other. Finally, we consider the case where capacity is fixed for both products, but the firm can set prices. For each case, we examine the sensitivity of optimal prices and capacities to the problem parameters. Finally, we consider the case where each product is managed by a product manager trying to maximize individual product profits rather than overall firm profits and analyze how optimal price and capacity decisions are affected.     

Modeling and analysis of effective ways for improving the reliability of second-hand products sold with warranty

Often, customers are uncertain about the performance and durability of the used/second-hand products. The warranties play an important role in reassuring the buyer. Offering the warranty implies that the dealer incurs additional costs to service any claims made by the customers. Reducing warranty costs is an issue of great interest to dealers. One way of improving the reliability and reducing the warranty servicing cost for second-hand items is through actions such as overhaul and upgrade which are carried out by the dealer or a third party. Improving actions allow the dealer to offer better warranty terms and to sell the item at a higher price. This paper deals with two effective approaches (virtual age approach and screening test approach) to decide on the reliability improvement strategies for second-hand products sold under various warranty policies (failure-free, rebate warranty, and a combination of free replacement and lump sum). A numerical example illustrates that from a dealer’s point of view, it is beneficial to carry out an improvement action only if the reduction in the warranty servicing cost is greater than the extra cost incurred due to this improvement action.     

封闭行星齿轮传动系统的可靠性研究

通过对封闭行星齿轮传动系统进行运动学及力学分析，结合可靠性设计和Savage等提出的单级行星齿轮传动的可靠度模型，建立了以输入构件转速和转矩为变量的构件负载与寿命关系表达式；基于系统可靠度的乘积定律，建立了典型的封闭行星齿轮传动系统的可靠度模型；结合实例，研究了负载、有效齿宽、功率分配系数等因素对系统及其零件可靠性的影响。研究表明：系统的可靠度随着功率分配系数、负载的增大而减小，随着有效齿宽的减小而减小；合理地配置齿数可使传动系统获得较大的可靠度。     

Game theory methodology for optimizing retailers’ pricing and shelf-space allocation decisions on competing substitutable products

This paper examines the influence of competition among supply chain partners on product demand. A power law demand function that depends on product pricing and shelf-space allocation (SSA) is used. The exponents in the power law are given by the elasticities of demand. In order to achieve the optimal pricing and SSA strategies in the presence of competition, game-theory-based methodologies—Cournot and Stackelberg games—are employed. For each type of game, a Nash equilibrium is achieved by optimizing the profit as a function of demand and price. A case study is presented to demonstrate the potential of this methodology. The results of this study indicate (1) how to achieve optimal pricing and SSA strategies, (2) how manufacturers can influence demand for a product, (3) that both prices and profits decrease using the Stackelberg game as compared with the Cournot game, and (4) that coordination beyond simple knowledge of price would be beneficial for improving overall profits.     

Product-mix decision in a mixed-yield wafer fabrication scenario

The product mix decision problem for semiconductor manufacturing has been extensively studied in literature. However, most of them are based on a high-yield scenario. Yet, in a low-yield manufacturing environment, some research claims that scrap low-yield lots in an early stage may produce more profit. Considering the early scrapping characteristics, this paper aims to solve the product mix decision problem for a mixed-yield scenario, which involves the simultaneous production of high-yield and low-yield products. A nonlinear mathematical program is developed to model the decision problem. Two methods for solving the nonlinear program are proposed. Method 1 converts the nonlinear program into a linear program by setting some variables as parameters. The method provides an optimal solution by exhaustively searching these parameterized variables and solving the LP models iteratively. Method 2 aims to reduce the computation complexity while providing a near optimal solution. Experiment results show that method 2 is better than method 1, when aggregately considering solution quality and computation efforts.     

汽车质量保证期故障信息的可靠性分析方法

利用维修网点的汽车质量保证期内的故障信息，对整车的可靠性进行分析评估。该方法可以有效地明确汽车可靠性改进工作的方向，并通过定期对整的平均故障间隔时间进行评估，来评价企业各项可靠性工作的综合效果。     

支持在线定制的商品和服务混合配置过程模型

为了更好地满足消费者的个性化需求,快速准确地完成在线产品和服务的混合配置,提出一种基于产品和服务多维混合约束的产品配置过程模型。该模型通过设置消费者对产品和服务的价格敏感系数,在产品零部件配置约束、服务配置约束以及产品与服务关联配置约束的共同作用下,以消费者效用和厂商利润最大化为目标,构建产品和服务的混合配置过程模型,并利用算法对该模型进行求解,从而得到在不同的价格敏感程度影响下的产品配置方案。以某汽车厂商的在线客户化定制过程为案例对模型进行应用和求解,得出针对不同敏感程度的消费者的产品配置方案,验证了该配置方法的实用性与可行性。