Detecting Changes in Field Reliability Using Data from a Complex Factory Screen

New products are sometimes screened in the factory before shipment to the field. We show how to use failure time data from one of these screens to predict early field reliability. These reliability predictions are more economical and timely than reliability estimates that wait for data from field tracking studies. Further, these predictions are continuously responsive to the changes in reliability that frequently occur during the manufacture of a new product, and therefore, can form the basis of a rapid-feedback system for manufacturing process control.     

Field Failure Data: an Alternative Proposal for Reliability Estimation

Product reliability is a very important issue for the competitive strategy of industries. In order to estimate a product's reliability, parametric inferential methods are required to evaluate survival test data, which happens to be a fairly expensive data source. Such costly information usually imposes additional compromises in the product development and new challenges to be overcome throughout the product's life cycle. However, manufacturers also keep field failure data for warranty and maintenance purposes, which can be a low‐cost data source for reliability estimation. Field‐failure data are very difficult to evaluate using parametric inferential methods due to their small and highly censored samples, quite often representing mixed modes of failure. In this paper a method for reliability estimation using field failure data is proposed. The proposal is based on the use of non‐parametric inferential methods, associated with resampling techniques to derive confidence intervals for the reliability estimates. Test results show the adequacy of the proposed method to calculate reliability estimates and their confidence interval for different populations, including cases with highly right‐censored failure data. The method is shown to be particularly useful when the sampling distribution is not known, which happens to be the case in a large number of practical reliability evaluations. Copyright © 2006 John Wiley & Sons, Ltd.     

论述数据中心电力系统的可用性

数据中心最关键的两个环节是电力和制冷。电力系统的可用性日益成为数据中心等级区分的一个关键指标。本文试图分析数据中心的几种典型电力系统配置,从理论方面剖析系统可靠性计算,为广大数据中心从业者提供帮助。     

无失效数据情形可靠性参数的置信限

推广了陈家鼎等的结果,对指数分布无失效数据情形,给出了可靠性参数的经典置信限和Bayes置信限,最后,结合实际问题进行了计算。     

成功企业经理人员成就取向的个案研究

研究选择了一家中国名的成功企业开展典型个案研究。通过结构化访谈、行为事件访谈等方法，较为全面、深入地考察了企业各层次经理人员的成就取向及特点。在对访谈材料综合分析的基础上，提出了经理人员成就取向的自我—社会取向和过程—结果取向的二维度结构，并由此组合成成就取向的四种成分：工作行为表现、工作目标超越、自我利益获取和团体利益贡献。总结提炼了每种成分在更一般意义上的关键特征。研究还发现了经理人员的成就取向与企业的组织化有密切的关系。     

Data Mining with Clustering Algorithms to Reduce Packaging Costs: A Case Study

Reducing package‐related cost is essential for various companies and institutions. Different packages are usually designed separately for each and every product, which results in less cost‐effective packaging systems. In this study, a data mining model with three clustering algorithms was developed to modularize a packaging system by reducing the variety of packaging sizes. The three algorithms were k‐means clustering, agglomerative hierarchical clustering and self‐organizing feature map. The package models with similar shapes and sizes were clustered automatically and replaced by one package model with a size that suited them all. The study also analysed the financial effects including the purchasing and inventory costs of the package material and the transportation cost of the packaged products. The case study was carried out at Ericsson to select the best clustering algorithm of the three and to test the effectiveness and applicability of the proposed model. The results show that the packaging system modularized by the agglomerative hierarchical clustering algorithm is more cost‐effective in this case compared with the ones modularized by the other two clustering algorithms and with the one without modularization. Copyright © 2017 John Wiley & Sons, Ltd.     

Analysis of Large Heterogeneous Repairable System Reliability Data With Static System Attributes and Dynamic Sensor Measurement in Big Data Environment

ABSTRACT

In the age of Big Data, one pressing challenge facing engineers is to perform reliability analysis for a large fleet of heterogeneous repairable systems with covariates. In addition to static covariates, which include time-invariant system attributes such as nominal operating conditions, geo-locations, etc., the recent advances of sensing technologies have also made it possible to obtain dynamic sensor measurement of system operating and environmental conditions. As a common practice in the Big Data environment, the massive reliability data are typically stored in some distributed storage systems. Leveraging the power of modern statistical learning, this article investigates a statistical approach which integrates the random forests algorithm and the classical data analysis methodologies for repairable system reliability, such as the nonparametric estimator for the mean cumulative function and the parametric models based on the nonhomogeneous Poisson process. We show that the proposed approach effectively addresses some common challenges arising from practice, including system heterogeneity, covariate selection, model specification and data locality due to the distributed data storage. The large sample properties as well as the uniform consistency of the proposed estimator are established. Two numerical examples and a case study are presented to illustrate the application of the proposed approach. The strengths of the proposed approach are demonstrated by comparison studies. Datasets and computer code have been made available on GitHub.     

含有屏蔽数据的截尾样本下部件的可靠性分析

基于屏蔽的系统寿命数据,讨论串联系统中Burr XII部件的可靠性估计问题.利用定数截尾样本,通过Bayes分析方法分别在平方损失、q-对称熵损失、Linex损失以及MLinex损失下给出了部件未知参数、可靠度函数和失效率函数的Bayes估计.最后通过Monte-Carlo方法进行随机模拟,研究截尾数和屏蔽水平对估计效果的影响并对各种估计进行了比较.     

Field Reliability Prediction in Consumer Electronics Using Warranty Data

In innovative fast product development processes, such as consumer electronics, it is necessary to check as quickly as possible, using field data, whether the product reliability is at the right level. In consumer electronics, some major companies use the Warranty Call Rate (WCR) for this purpose. This paper discusses extensively the theoretical and practical drawbacks of the WCR. Subsequently, it is demonstrated, using a Weibull failure distribution, that only a few months after product launch, say three months, the warranty data offer the opportunity to estimate the parameters of the failure distribution. Of course, this requires that the warranty data are available in the quality department. Unfortunately, for some companies the field feedback information process from the repair centres to the quality department causes a delay of several months. These companies have to speed up their field feedback information process before they can fully take advantage of the proposed estimation procedure. Copyright © 2006 John Wiley & Sons, Ltd.     

名牌系统工程应用案例及其启示

对名牌系统工程体系及名牌创造发展系统模型进行了概述，给出了烟台威龙葡萄酒股份有限公司实施名牌创造工程的实际应用案例，并揭示了本案例对一般企业创造发展名牌的几点启示。     

Time Reliability Measures in bus Transport Services from the Accurate use of Automatic Vehicle Location raw Data

Archived automatic vehicle location (AVL) data are widely used in bus transportation, but typically contain anomalies, such as missing data points and unseen bus overtakings. These anomalies may alter the measurement of time reliability (i.e., headways and schedule time deviations) of buses at stops with respect to passenger experiences. However, in many studies, anomalies are ignored, neglected, or partially addressed. This paper investigates the effect of AVL anomalies on headways and schedule deviations, which are keys for regularity and punctuality evaluations and are well‐practicized among bus operators worldwide. The analysis is carried out on six scenarios, each representing a combination of AVL data anomalies. The outcomes show that addressing anomalies result in more severe regularity measures, which point out criticalities suffered by passengers, whereas it can be skipped for the measurement of punctuality. In addition, an increase of 5% of missing data results in the increase of 5% in the coefficient of variation of the headway, but it does not lead to meaningful variations in punctuality measures. These results are useful for both practitioners interested in passenger‐oriented measurement of time reliability and researchers working on the disclosure of the determinants of unreliability. Copyright © 2016 John Wiley & Sons, Ltd.     

Reliability Analysis of Non-Parametric Statistical Tests for the Evaluation of Linear Drift in Experimental Data

Abstract: During usual data gathering, the statistical analysis efficiency strongly depends on the noise level superimposed on the signal. It has been found that some well known statistical tests, commonly utilised in data acquisition in order to detect the presence of drift, can fail under some conditions. Thus, a statistical procedure for the predictive reliability estimation of the utilised statistical method could be useful in the design of experimental analysis. This paper reports the results of a simulation study carried out to evaluate the performance in drift detection of non-parametric tests such as the Wald-Wolfowitz run test, in comparison with the Mann-Whitney, reverse arrangement test. In order to detect the sensitivity of the tests to evaluate a monotonous drift, a simulation program was developed. In the program a Gaussian raw data sequence with a linear pattern of variable slope and with variable variance was simulated and given as the input to the tests. The capability to detect the presence of drift as a function of angular coefficient and variance of the noise superimposed on the signal was verified. The obtained data were synthesised in graphs so that the experimentalist could determine preliminarily the effectiveness of each of the considered statistical methods in terms of percentage of success in detecting the presence of drift phenomena as a function of drift relevance and the noise amplitude. Finally, the graphs permitted the elucidation of the causes of contradictory failing results observed in long term experimental analysis.     

Integrated Approach for Field Reliability Prediction Based on Accelerated Life Testing

ABSTRACT

To predict field reliability using analytical modeling, several important reliability activities should be conducted, including failure mode and effect analysis, stress and usage condition analysis, physics of failure analysis, accelerated life testing and modeling, and cumulative damage modeling if needed. With all of the mentioned activities and results, the field reliability confidence limit can be predicted at a certain confidence level, if a modeling framework can be established. This article builds such an integrated process and comprehensive modeling framework, especially with cumulative damage rules when the certain field stresses are random processes. An engineering product is provided as an application to illustrate the effectiveness of proposed method.     

Effect of Field Stress Variance on Test to Field Correlation in Accelerated Reliability Demonstration Testing

This paper discusses the effect of field stress variance on the value of demonstrated reliability. In many cases, the acceleration factor for a reliability demonstration test is calculated based on a high percentile field stress level, typically corresponding to severe user or environmental conditions. In those cases, the actual field reliability for the population will be higher than that demonstrated by the test. This paper presents a mathematical approach to estimating ‘true’ field reliability based on the acceleration model and stress variable distribution over the product field population. This method is illustrated by an example of automotive electronics reliability demonstration testing and has a wide range of practical applications. Copyright © 2014 John Wiley & Sons, Ltd.     

Warranty Data Analysis: A Review

Warranty claims and supplementary data contain useful information about product quality and reliability. Analysing such data can therefore be of benefit to manufacturers in identifying early warnings of abnormalities in their products, providing useful information about failure modes to aid design modification, estimating product reliability for deciding on warranty policy and forecasting future warranty claims needed for preparing fiscal plans. In the last two decades, considerable research has been conducted in warranty data analysis (WDA) from several different perspectives. This article attempts to summarise and review the research and developments in WDA with emphasis on models, methods and applications. It concludes with a brief discussion on current practices and possible future trends in WDA. Copyright © 2012 John Wiley & Sons, Ltd.     

商用车组装线平衡及案例研究

针对某商用车有限公司组装线自动化程度不高、作业繁杂的现状,应用三项原则对其予以简化,根据组装线平衡理论进行建模,在不改变原组装线布局基础上,采用重要位置排序法初始化作业分配方案,通过作业交换和转移操作,设置合理的参数数值,进行迭代优化.所得结果可大幅提高生产率;另外通过改进组装线布局,生产率可得到进一步提高.     

A Statistical Physics Method of Electronic Device Reliability Testing from Working Data

A combined method is used to estimate the parameters for a mixture of exponential and Weibull distributions. Examples are given of the method applied in reliability analysis for high-power electronic devices.     

企业流程再造中IT技术作用的案例分析

通过Ａ集团的ＩＴ技术应用的案例,分析了ＩＴ技术在企业流程再造中的作用,对Ａ集团的决策、财务、设计、制造、检测、仓库管理、售后服务、办公自动化等业务流程再造中ＩＴ技术的作用进行了详细的研究。认为ＩＴ技术在流程再造中确实起到了使能器和实现器的作用。