Improving wooden parts' quality by adopting DMAIC procedure

This paper utilizes the six‐sigma define‐measure‐analyze‐improve‐control (DMAIC) procedure to improve quality through enhancing the measurement system capability (MSC) of a wood industry. In the first stage, the major reported defects at the customer site are identified, and then the performance of the measurement system is evaluated by conducting a gage repeatability and reproducibility (GR&R) experiment on a drilling process, i.e. the outputs of a drilling machine. The obtained results show that the measurement system is inadequate and results in wrong classification of the produced wooden parts. Thus, to improve MSC, corrective actions, including operators' training, proper selection of measuring instruments, and improved measuring methods, were implemented. To determine the achieved improvement in MSC, a second GR&R study was carried out under the same conditions. In conclusion, adopting the DMAIC procedure including GR&R study turns out to be an effective method in improving the quality system involving measurements. Copyright © 2008 John Wiley & Sons, Ltd.     

A Multiplicative Model for Gauge R & R Studies

We introduce a multiplicative measurement error model and analyze a gauge R & R study with the new model using data from a sample exchange program. Some aspects of designing a gauge R & R study are considered. Also, we analyze data from a factorial experiment where the measurement error arises from the new model using a simultaneous analysis of experimental and gauge R & R study data. WinBUGS code for these analyses is provided. Copyright © 2014 John Wiley & Sons, Ltd.     

Implementing Evaluation of the Measurement Process in an Automotive Manufacturer: a Case Study

Reducing process variability is presently an area of much interest in manufacturing organizations. Programmes such as Six Sigma robustly link the financial performance of the organization to the degree of variability present in the processes and products of the organization. Data, and hence measurement processes, play an important part in driving such programmes and in making key manufacturing decisions. In many organizations, however, little thought is given to the quality of the data generated by such measurement processes. By using potentially flawed data in making fundamental manufacturing decisions, the quality of the decision‐making process is undermined and, potentially, significant costs are incurred. Research in this area is sparse and has concentrated on the technicalities of the methodologies available to assess measurement process capability. Little work has been done on how to operationalize such activities to give maximum benefit. From the perspective of one automotive company, this paper briefly reviews the approaches presently available to assess the quality of data and develops a practical approach, which is based on an existing technical methodology and incorporates simple continuous improvement tools within a framework which facilitates appropriate improvement actions for each process assessed. A case study demonstrates the framework and shows it to be sound, generalizable and highly supportive of continuous improvement goals. Copyright © 2003 John Wiley & Sons, Ltd.     

轴瓦厚度测量机稳定性的测量分析

介绍了轴瓦厚度测量系统分析计划的制订,测量系统偏倚特性、稳定性和线性分析.对测量系统的重复性与再现性分析步骤、计算过程、分析结果做了详尽的剖析与讨论.认为自行开发研制的轴瓦厚度测量机的偏倚特性、稳定性和线性能满足测量要求,其重复性与再现性指标R&R%<30%,基本上具有所需的测量能力.     

Posterior distributions for functions of variance components

This paper uses a Bayesian approach to examine the posterior distributions of linear and non-linear functions of variance components in balanced two-way analysis of variance designs. The paper shows how exact posterior distributions for such functions can be readily described using Monte Carlo simulations where independent draws from the distributions are obtained. It is thus very straightforward to obtain percentiles, means, standard deviations, and other summary measures for the posterior distributions.     

测量系统分析在曲轴测量机上的应用

本文介绍测量系统分析的一般概念,探讨、研究曲轴测量机这一测量系统所涉及的偏倚、线性、稳定性、重复性等一系列问题,提出在实际生产现场评定曲轴测量机的方法。     

A model‐based approach for attribute gauge analysis

A new method is proposed for the attribute gauge study. A mathematical model based on the Gauge Performance Curve (GPC) is introduced and the connection between the model parameters and gauge characteristics is discussed. The ability of the whole measurement system (the process and the gauge together) is characterized by two key probabilities: the probability of a rejected part being good and the probability of an accepted part being bad. These probabilities can be calculated either with the proposed mathematical model of GPC (GPC‐method) or by using relative frequencies (AIAG‐type method). The performance of the two approaches has been compared, and the proposed GPC‐method is proven to be statistically favourable. Copyright © 2010 John Wiley & Sons, Ltd.     

Analysis of Two-dimensional Gage Repeatability and Reproducibility

Recent statistical work is applied to measuring imbalance in a single plane, often referred to as static imbalance, for a rigid rotor. The two-dimensional repeatability and reproducibility of imbalance measurement are estimated by circles constructed from MANOVA-based method-of-moments and the results are compared to those of one-dimensional repeatability and reproducibility using the same measurement data. The results of both the one-dimensional and the two-dimensional repeatability and reproducibility are interpreted in terms of capability or how the measurement variation relates to rotor imbalance specification or tolerance.     

示差扫描热量计高温校准的探讨与应用

探讨了示差扫描热量计高温校准的校准项目、校准方法和所用的参考物质,给出了计量性能的要求,并列举了校准的应用实例,同时对校准过程中出现的问题进行了讨论,方便对DSC在高温应用时的计量性能评价.     

Gauge capability studies for attribute data

A gauge repeatability and reproducibility (R&R) method is developed to assess the capability of a measurement system. Although gauge capability studies have received substantial attention, few studies have investigated attribute data despite their wide application in industry. The primary aim of this research is to develop a procedure, based on the generalized linear model, to evaluate the R&R of a measurement system for attribute data. To calculate repeatability of a system, the procedure integrates the iterative weighted least squares (IWLS) method and deviance analysis. The proposed procedure is applied to an inclusion measurement system to verify its adequacy to model the process capability. Copyright © 2007 John Wiley & Sons, Ltd.     

关于国际标准ISO 5725：1994的一些思考与讨论

本文针对国际标准ISO5725：1994《测量方法与结果的准确度（正确度与精密度）》中的概念及定义进行了探讨。对其中涉及的二个主要概念：“实验室间方差”及“再现性方差”提出了质疑。给出了解决方案。目的是使该标准具有更严密的科学性和逻辑性。     

测量系统的R&R分析在企业质量改进中的应用

测量系统是指为了完成对被测对象质量特征的测量所需求的人员、量具、程序、软件、操作等的集合。建立准确有效的测量系统永远是企业实现质量改进的第一步。本文阐述了测量系统分析的基本内容及方法，通过一个案例介绍了测量系统分析在企业应用的过程，并提出了应用时的几点注意事项。     

Improving the Surface Electric Potential Measurement Capability for Textile Materials

The system currently employed for measuring the electric potential of the surface of textile fabrics consists in an electrostatic probe connected to an electrostatic voltmeter. The primary aim of the present work is to improve the capability of this measurement system, as evaluated by gauge repeatability and reproducibility studies. The experiments were conducted on samples of polypropylene non‐woven fabrics, electrostatically charged by exposing them to a negative corona discharge from a custom‐designed electrode system. A first series of fully operator‐controlled measurements pointed out the need to automatically control the relative position between the sample and probe, so that to eliminate the variability due to the non‐uniform structure of the non‐woven fabrics. The following series of partly automated experiments revealed that the repeatability and the reproducibility of the measurements are negatively affected by the decay of the electric potential at the surface of the samples. The best gauge capability is obtained when the measurements are delayed with respect to the moment of corona charging, in order to reduce the variability due to the fact that the samples characteristics change in time. Copyright © 2013 John Wiley & Sons, Ltd.     

集成量纲分析的多元测量系统能力评价

多元测量系统分析是多元质量控制的重要内容。现有的研究主要是利用统计学的方法,如多元方差分析法和主成分法等进行分析评价。本文提出了基于量纲分析的多元测量系统能力评价方法,集成物理和统计分析方法,利用物理中量纲分析的方法研究产品各相关变量之间的物理关系,将多元测量系统问题转化为一元测量系统问题。从而可以利用一元测量系统能力评价的统计方法及指标来对测量系统的能力进行评估。同时,本文重复了纸飞机试验,并运用基于量纲分析的多元测量系统能力评价方法对纸飞机的测量系统进行了分析评价,验证了该方法的有效性。