Divide and recombine approach for warranty database: estimating the reliability of an automobile component

The continuously updated database of failures and censored data of numerous products has become large, and on some covariates, information regarding the failure times is missing in the database. As the dataset is large and has missing information, the analysis tasks become complicated and a long time is required to execute the programming codes. In such situations, the divide and recombine (D&R) approach, which has a practical computational performance for big data analysis, can be applied. In this study, the D&R approach was applied to analyze the real field data of an automobile component with incomplete information on covariates using the Weibull regression model. Model parameters were estimated using the expectation maximization algorithm. The results of the data analysis and simulation demonstrated that the D&R approach is applicable for analyzing such datasets. Further, the percentiles and reliability functions of the distribution under different covariate conditions were estimated to evaluate the component performance of these covariates. The findings of this study have managerial implications regarding design decisions, safety, and reliability of automobile components.

Optimal replacement policy of products with repair-cost threshold after the extended warranty

The reliability of the product sold under a warranty is usually maintained by the manufacturer during the warranty period. After the expiry of the warranty, however, the consumer confronts a problem about how to maintain the reliability of the product. This paper proposes, from the consumer's perspective, a replacement policy after the extended warranty, under the assumption that the product is sold under the renewable free replacement warranty (RFRW) policy in which the replacement is dependent on the repair-cost threshold. The proposed replacement policy is the replacement after the extended warranty is performed by the consumer based on the repair-cost threshold or preventive replacement (PR) age, which are decision variables. The expected cost rate model is derived from the consumer's perspective. The existence and uniqueness of the optimal solution that minimizes the expected cost rate per unit time are offered. Finally, a numerical example is presented to exemplify the proposed model.

Optimal Extended Warranty Policies under Different Maintenance Options

Extended warranty has recently obtained increasing attention from both manufacturers and customers in China. In this paper,given the reality of China, two types of non-renewing extended warranty were proposed: one-dimensional extended warranty and two-dimensional extended warranty. And a combined warranty policy including pro-rata warranty policy and free-repair warranty policy was applied in these two types of warranty. Then the expected life-cycle cost models from the manufacturer and consumer's perspectives were developed considering different maintenance options. The optimal warranty policy, maintenance options,and warranty price were adopted in terms of a win-win interval which was determined by the maximum extra cost the consumer should pay and the minimum price the manufacture should sell at the extended warranty. Finally,a case study was given to prove the effectiveness and validity of the model.

A decision model of optimal production reliability and warranty length in an imperfect production system

A decision model to maximize the total profit of manufacturers in an imperfect production system is constructed.In this model the production reliability and the warranty length are jointly used as decision variables for the case that products are sold with a warranty i.e. the demand is dependent on the warranty length and sale price.Also all the non-conforming quality defective items in the production process are refurbished to conform to quality ones at a cost. The existence and uniqueness of the optimal values of production reliability and the warranty length are proved by using the Euler-Lagrange method in analyzing the model.A numerical example is also provided to illustrate the effectiveness of the decision model.The sensitivity analysis of the key parameters of the optimal solution and objective value is presented in addition.

Optimization of post-warranty sequential inspection for second-hand products

This paper considers an optimal sequential inspection schedule for a second-hand product after that the free nonrenewable warranty is expired. The length of warranty is prespecified and during the warranty period, the product is minimally repaired by the dealer when it fails. Following the expiration of the non-renewing warranty, the product is inspected and upgraded sequentially a fixed number of times at the expenses of the customer.At each inspection, the failure rate of the product is reduced proportionally so that the product is upgraded. The product is assumed to deteriorate as it ages and the replacement of the product occurs when a fixed number of inspections are rendered. In addition,the intervals between two successive inspections are assumed to decrease monotonically. The main objective of this paper is to determine the optimal improvement level to upgrade the product at each inspection so that the expected maintenance cost during the life cycle of the product is minimized from the perspective of the customer. Under the given cost structures, we derive an explicit formula to obtain the expected maintenance cost incurred during the life cycle of the product and discuss the method to find the optimal level of the improvement analytically in case the failure times follow the Weibull distribution. Numerical results are analyzed to observe the impact of relevant parameters on the optimal solution.

Warranty Cost Model Based on Optimal Preventive Maintenance Operations for Repairable Products

Most warranty cost models based on preventive maintenance operations are assumed that products improve at each preventive maintenance （PM） operation and the failure rate is reduced to the failure rate of new products or to some specified level. To make warranty cost models more suitable to real operations, a modeling method of the PM warranty cost was proposed with the situation where each PM operation slowed the rate of product degradation. A warranty cost model was built on PM operations. On the basis of the cost model, both without and with reliability limit PM warranty policy, algorithms were presented to derive the optimal PM number and the optimal PM interval with an objective of minimizing expected total warranty cost over a t＇mite warranty period. Finally, to demonstrate the feasibility of the presented modeling method, Weibuil distribution cases were tested by numerical simulations. The simulation results indicate that the proposed modeling method is feasible and valid for resolving the optimal solution of the product warranty cost.

Reliability Model for Key Devices with Compound Preventive Warranty

With the warranty requirements of key and important devices,the compound preventive warranty policy was introduced.For the effectiveness of compound preventive maintenance, the maintenance mode of periodic replacement with functional checks was adopted, its failure risk analysis was carried on, and the warranty reliability model was established. On the basis of above research,a numerical example was given to illustrate the engineering application and generality of the warranty reliability model.

Two-stage optimization model for renewing warranty considering warranty deadline

Renewing warranty can provide customers with better service,and thus help manufacturers to gain market opportunities.In engineering practice,the cost for replacement is usually higher than the cost for maintenance,hence manufacturers often face huge challenge to reduce the warranty service cost.With consideration of the warranty deadline,we propose a two-stage optimization model for renewing warranty.In the first stage,a renewing warranty with deadline(RWD)policy is implemented,where the deadline represents the cumulative uptime threshold.When the cumulative uptime exceeds the deadline,the product will be minimally repaired and kept to the residual warranty period.When RWD is expired,the replacement warranty with limited repairs(RWLR)policy is applied.Under the free replacement and pro-rata warranty policy,the corresponding two-stage cost optimization model is established from the manufacturer’s perspective,the aim is to minimize the cost rate and obtain the optimal warranty period.A numerical example is provided to illustrate the validity of the proposed model,and the sensitivity analysis is also carried out.

A customized extended warranty policy with heterogeneous usage rate and purchasing date

To increase customers'satisfaction and promote product's competitiveness,a customized extended warranty(EW)policy is proposed,where the diversities in both the usage rate and purchase date are considered.The marginal approach is applied to describe the product's two-dimensional failure in terms of age and usage,respectively.Moreover,minimal repair is adopted to restore the failure,and the virtual age method is applied to depict the effect of preventive maintenance(PM).On this basis,an optimization model is established to minimize the maintenance cost and warranty cost from the manufacturer's view,and multiple factors are taken into account,including the PM's intensity and its period,and EW's interval,etc.A numerical case study is provided to illustrate the effectiveness of the proposed approach.The results show that by considering the product's usage rate and the purchasing date of EW,the number of failures as well as the cost of maintenance and warranty can be reduced effectively.

Optimization of extended warranty cost for multi-component systems with economic dependence based on group maintenance

During extended warranty(EW)period,maintenance events play a key role in controlling the product systems within normal operations.However,the modelling of failure process and maintenance optimization is complicated owing to the complex features of the product system,namely,components of the multi-component system are interdependent with each other in some form.For the purpose of optimizing the EW pricing decision of the multi-component system scientifically and rationally,taking the series multi-component system with economic dependence sold with EW policy as a research object,this paper optimizes the imperfect preventive maintenance(PM)strategy from the standpoint of EW cost.Taking into consideration adjusting the PM moments of the components in the system,a group maintenance model is developed,in which the system is repaired preventively in accordance with a specified PM base interval.In order to compare with the system EW cost before group maintenance,the system EW cost model before group maintenance is developed.Numerical example demonstrates that offering group maintenance programs can reduce EW cost of the system to a great extent,thereby reducing the EW price,which proves to be a win-win strategy to manufacturers and users.

guarantee同warranty的区别

虽然这两个词可以相互替换使用,但是实际上它们还是有些区别的。特别是在广告术语中,区分两者是非常必要的。这主要是两者在广告中所要表达的意思和所起的怍用有所不同。下面就从术语的角度将这两个词加以分析和说明。有一本名为 A Guide to Correct Legal Issues In Advertising(by

批发和寄售模式下电商平台延保服务定时定价策略

针对电商平台提供产品延保服务的最优定时定价策略问题,考虑电商平台与制造商的批发和寄售两种模式,建立Stackelberg博弈模型,分析比较电商平台延保服务最优定时定价策略的差异及其原因,揭示不同模式、延保成本和佣金水平等对最优延保服务策略的影响规律。研究表明,在批发模式下,延保服务使电商平台受益、制造商利润受损。在寄售模式下,当佣金较高时,电商平台会提供延保服务,且不影响制造商利润;当佣金较低且基础质保效用较大时,制造商与电商平台可以在含有延保服务的寄售模式下形成双赢。两种模式下延保服务的需求与单价相同,延保时长与产品价格存在比例关系,并受基础质保和延保效用、延保价格和成本系数等影响。对于佣金不同的产品,电商平台应提供差异化延保服务定时定价策略。

服务经济下网购消费者延保服务购买意向研究

延保服务因其盈利能力和风险规避属性受到电商平台和消费者的青睐。以网购消费者在线延保服务购买行为为研究对象,基于技术接受模型和计划行为理论构建研究模型,通过在线收集的610份有效数据对模型及假设进行验证分析,探索影响企业延保服务网络零售的因素,揭示相应的作用机理,为网络零售业高质量发展提供运营与政策优化方面的借鉴。研究发现:感知有用性和感知易用性对消费者延保服务购买意向均有显著的正向影响,且感知有用性的作用强度相对较大;购买态度作为中介变量能够增强感知有用性和感知易用性对延保服务购买意向的正向影响;主观规范和知觉行为控制显著正向影响消费者延保服务的购买意向,且二者作为调节变量能够分别增强感知有用性、感知易用性对延保服务购买意向的影响;感知有用性影响消费者的购买态度,进而形成消费者延保服务购买意向,是最显著的影响路径之一。

考虑渠道结构的竞争性网购供应链产品-延保联合定价策略

本文考虑网络商店销售由两个竞争性制造商生产的同类但具有差异化的替代性产品,在网络商店提供延保的服务模式下分别针对RO/MO/PO三种典型渠道结构构建产品-延保决策模型,分析了制造商之间,以及制造商与网络商店之间的互动决策。研究结果表明,各渠道结构下供应链均存在唯一的均衡,使供应链系统中各参与者的利润同时实现最大化;当制造商之间的竞争强度处于中等及以下水平时,RO渠道结构有利于系统各参与者;当竞争强度处于中高水平区间时,采用MO渠道结构会拉大制造商之间的绩效差距;当竞争强度较高时,采用RO渠道结构有助于提升两个制造商的利润,但更高的竞争强度更有利于网络商店且在高强度区间内的竞争波动对零售商和制造商的影响并非线性,即存在具有区间依赖和强度差异特性的影响。此外,较高的平台佣金率并非总有利于网络商店,反而可能影响其销售渠道选择;消费群体延保服务质量敏感性存在差异,该差异决定相应消费群体的延保购买率上限且延保服务质量成为影响高端群体延保购买率的重要因素。

基于系统动力学的医疗设备维修保修采购风险模型研究

目的:研究基于系统动力学的医疗设备维修保修风险模型,以解决医疗设备维修保修采购过程中廉政风险多发、成交价格居高和采购时效低下等问题。方法:分析医疗设备维修保修采购风险形成风险矩阵,绘制风险矩阵图;围绕医疗设备维修保修采购价格风险、进度风险和廉政风险构建系统动力学模型,通过构建因果关系图和存量流量图,揭示医疗设备维修保修采购风险影响要素之间的因果关系和反馈效应。对比2022年解放军总医院采用基于系统动力学的医疗设备维修保修采购风险模型进行实践的风险变化效果。结果:基于系统动力学的医疗设备维修保修风险模型进行风险管理控制后,采购价格风险增加量从控制前的0.54降至0.27,廉政风险增加量从控制前的0.27降至0.05,进度风险增加量减小较为缓慢;降低风险阈值后,价格风险增加量和价格风险明显下降;风险阈值从60降低至40时,项目成功率比控制前提高6.52%,质疑投诉率下降6.61%。结论:基于系统动力学的医疗设备维修保修风险模型严格采购需求端管理,实行限价和审价管理,通过优化采购方式、构建谈判限价模型和完善审价定价机制,能够有效清除价格风险衍生出的廉政风险和进度风险。

考虑回收规模和再制造延保服务的回收渠道决策

为探究回收规模和再制造延保服务对闭环供应链回收渠道决策的影响,以制造商提供延保服务、零售商销售延保服务的模型为基础,在考虑回收规模促进再制造延保服务的情形下,运用Stackelberg博弈方法建立集中决策模型和制造商、零售商分别负责回收工作的两种延保服务销售分散决策模型。结果表明:回收规模对不同回收渠道具有一定的限制作用;集中决策模型具有最高利润,分散决策模型中由零售商负责回收工作时制造商和零售商的利润最高。同时,分析回收规模对不同模型决策的影响,指出集中决策和零售商负责回收工作时回收规模的扩大会产生积极影响;制造商负责回收工作时回收规模的扩大会产生消极影响。

深空探测器研制风险产品保证策划与实施

深空探测任务主要面临的研制风险包括技术跨度大,环境要素新,新技术储备不足,关键不可逆环节多,对设计正确和自主功能要求高,研制试验复杂且难以验证,研制周期紧张导致多线并行。针对以上难点和风险点,以火星探测任务为例,开展了具有火星任务特点的产品保证策划与实施,全周期遵循“五个坚持”的总体思路,通过发挥总体作用,加强技术风险识别和管控,强化产品过程控制,严格试验验证和统筹资源保障等,确保了我国首次火星探测任务圆满成功。

信息不对称下绿色供应链延保服务策略研究

为了探讨延保服务对绿色供应链成员决策及信息共享的影响,分别构建了零售商不提供延保、零售商提供延保及零售商与第三方企业合作提供延保的三种模型。通过对比不同延保模型得出以下结论:(1)企业的延保服务能够有效提升产品绿色度和渠道成员利润,且零售商单独提供延保服务能够最有效的改善绿色供应链绩效;(2)延保服务对零售商信息共享的影响取决于制造商对市场需求预测值的大小,即当制造商对市场需求的预测值较小时,延保服务有利于零售商信息共享,反之则不利;(3)零售商进行信息共享总是对制造商和第三方企业有利,但不一定有助于提升自身利润和产品绿色度。

基于区块链信任机制的延保供应链决策优化

延保服务供应链中消费者、制造商、零售商各自的利益目标存在冲突,导致相互之间的信任关系面临挑战。针对这一问题,考虑到区块链信任机制对于打消消费者在延保服务购买决策中的信任顾虑、构建延保供应链成员信任关系具有可行性,而区块链技术在提升消费者和企业间信任度的同时,也为企业带来额外的运营成本,为此构建基于区块链信任机制的延保供应链决策模型,分析延保供应链实施区块链的条件及实施区块链的策略。研究表明:(1)在技术价值目标下,存在一个最优的消费者信任度差,使制造商愿意实施区块链;在经济价值目标下,制造商考虑企业信任效用时更愿意实施区块链,而零售商则更愿意跟从制造商实施区块链。(2)未实施区块链下,消费者信任度与延保供应链策略呈反向影响关系;实施区块链后,消费者的信任度与延保服务价格、延保服务水平和延保供应链利润呈正向变化关系。研究结论为企业的延保供应链运营与决策提供参考。

消费者具有质量偏好的双渠道延保供应链绩效比较研究

考虑消费者对产品具有质量偏好,制造商生产异质产品,分别构建不提供延保、仅制造商提供延保、仅零售商提供延保等三种模式下的双渠道供应链Stackelberg博弈模型。通过分析制造商和零售商的最优决策,比较不同模型下的供应链绩效,探讨了延保服务分销策略选择问题。结果表明:提供延保服务可以使提供延保服务主体的自身利润增加,而不提供延保服务的主体利润不变;提供延保服务可以使提供延保服务主体的自身利润大于不提供延保服务的主体的自身利润;制造商提供延保和零售商提供延保均会提高供应链系统利润,而制造商销售延保服务可以更有益于供应链整体绩效的提高。最后,本文运用数值算例分析验证了所得结论的有效性并给出相应的管理启示。