Showing papers in "Journal of Quality Technology in 2001"
1,239 citations
TL;DR: In this article, nonparametric statistical methods are used to evaluate the performance of a set of NQM methods. But they are not suitable for non-parametric methods.
Abstract: (2001). Nonparametric Statistical Methods, 2nd, Ed. Journal of Quality Technology: Vol. 33, No. 2, pp. 259-259.
1,051 citations
TL;DR: In this paper, the authors present a practical nonparametric statistical model for non-parametric statistics, which they call Practical Nonparametric Statistics, 3rd Ed. (3rd Ed.).
Abstract: (2001). Practical Nonparametric Statistics, 3rd Ed. Journal of Quality Technology: Vol. 33, No. 2, pp. 260-260.
791 citations
TL;DR: An overview of the literature on nonparametric or distribution-free control charts for univariate variables data is presented and connections to some areas of active research are made, such as sequential analysis, that are relevant to process control.
Abstract: The literature on nonparametric or distribution-free control charts for univariate variables data is examined. The advantages of these charts have over more traditional distribution-based control charts are demonstrated. Constructive criticism of the li..
331 citations
TL;DR: A new EWMA chart is proposed which effectively combines the usual two EWMA charts into one chart and has the property that it is effective in detecting both increases and decreases in mean and/or variability.
Abstract: Two EWMA charts are usually required to monitor both process mean and variability. In this paper, we propose a new EWMA chart which effectively combines the usual two EWMA charts into one chart. In...
214 citations
TL;DR: The Six Sigma improvement methodology has received considerable attention recently, not only in the statistical and quality literature, but also within general business literature as discussed by the authors, and it has been used in many projects.
Abstract: The Six Sigma improvement methodology has received considerable attention recently, not only in the statistical and quality literature, but also within general business literature. In published dis...
185 citations
TL;DR: In this paper, the authors investigate control charts for monitoring a process to detect changes in the mean and variance of a normal quality variable when an individual observation is taken at each samplacement.
Abstract: In this paper we investigate control charts for monitoring a process to detect changes in the mean and/or variance of a normal quality variable when an individual observation is taken at each sampl...
173 citations
TL;DR: In this paper, the authors examined multiple responses with multiple responses whose means, variances, and correlations depend on experimental factors and the experimental factors used to improve product or process quality and to make them more robust.
Abstract: Statistically designed experiments are widely used to improve product or process quality and to make them more robust Experiments with multiple responses are examined whose means, variances, and correlations depend on experimental factors Analys
159 citations
TL;DR: This paper investigates CUSUM control charts for monitoring the process mean for the situation in which observations from the process can be modeled as an AR(1) process plus an additional random error.
Abstract: Control charts for process monitoring have traditionally been designed and evaluated under the assumption that observations on the process output at different times are independent. However, autoco...
153 citations
TL;DR: It is better to use the maximum likelihood change point estimator when a CUSUM or EWMA control chart signals a change in the process mean, and an approach based on the likelihood function for estimating a confidence region for the process change point is presented.
Abstract: Knowing when a process has changed would simplify the search for and the identification of the special cause. In this paper, we compare the maximum likelihood estimator of the process change point ...
141 citations
TL;DR: Significant measurement error often exists in quality control applications as mentioned in this paper, which is known to result in reduced power to detect a given change in the mean or variance of a quality chara...
Abstract: Significant measurement error often exists in quality control applications. Measurement error is known to result in reduced power to detect a given change in the mean or variance of a quality chara...
TL;DR: It is shown how the split-plot structure affects estimation, precision, and the use of resources in fractional factorial design and how these issues affect design selection in a real industrial experiment.
Abstract: It is often impractical to perform experimental runs of a fractional factorial in a completely random order. In these cases, restrictions are imposed on the randomization of the experimental trials, and the design is said to have a split-plot structure...
TL;DR: In this article, statistics and data analysis: From Elementary to Intermediate, from elementary to intermediate, from the perspective of quality of education, is presented in the context of data analysis.
Abstract: (2001). Statistics and Data Analysis: From Elementary to Intermediate. Journal of Quality Technology: Vol. 33, No. 3, pp. 385-386.
TL;DR: In this paper, the authors compare split-plot designs to completely randomized experiments in terms of D-efficiency and show that the former are often more efficient than the latter, while the latter is more difficult to change.
Abstract: Split-plot designs are heavily used in industry, especially when factor levels are difficult or costly to change or to control. This is because this type of design avoids too many changes of the whole plot factor levels, which leads to considerable savings in cost and time. The purpose of this chapter on split-plot designs is twofold. Firstly, we investigate to what extent the designs of Chapter 7 can be improved if the number of whole plots is increased. Secondly, we compare split-plot designs to completely randomized experiments in terms of D-efficiency. It turns out that the former are often more efficient than the latter.
TL;DR: The sixth edition of Probabil11 ity and Statistics for Engineers, by Robert A. Johnson, provides the reader with many new case studies, new actual data sets, and updated procedures.
Abstract: (2001). Miller and Freund's Probability and Statistics for Engineers, 6th Ed. Journal of Quality Technology: Vol. 33, No. 1, pp. 122-122.
TL;DR: In this paper, a model demonstrates that the performance of multivariate control charting methods based on measured covariates is not directionally invariant to shifts in the mean vector of the underlying process variables.
Abstract: A model demonstrates that the performance of multivariate control charting methods based on measured covariates is not directionally invariant to shifts in the mean vector of the underlying process variables. This is the case even if it is directionally..
TL;DR: Numerical tests have indicated that the synthetic chart has a higher power for detecting process shifts in the fraction nonconforming than both the np chart and the conforming run length chart and may substantially enhance the effectiveness of statistical process control for attributes.
Abstract: In this paper we propose a new control chart, the synthetic control chart, for the detection of increases in the fraction nonconforming (p) The operation, design, and performance of this control c
TL;DR: In this article, the authors present an Introduction to Statistical Quality Control, Fourth Edition, with a focus on statistical quality control in the context of statistical data collection and statistical quality analysis.
Abstract: (2001). Introduction to Statistical Quality Control, Fourth Edition. Journal of Quality Technology: Vol. 33, No. 4, pp. 524-525.
TL;DR: The usefulness of Hotelling's T2 statistic for monitoring batch processes in both Phase I and Phase II operations is shown and a variety of data sets taken from different types of industrial batch processes are used.
Abstract: The usefulness of Hotelling's T2 statistic for monitoring batch process in both Phase I and Phase II operations is discussed. For Phase I operation where the focus is on detecting and removing outliers, consideration is given to batch processes wh..
TL;DR: In this article, variable sample size (VSS) and variable sampling interval (VSI) are used for process monitoring, and the VSS and VSI are combined with variable sampling interv...
Abstract: Traditional control charts for process monitoring are based on taking samples of fixed size from the process using a fixed sampling interval. Variable sample size (VSS) and variable sampling interv...
TL;DR: This paper presents several examples of designed experiments with nonnormal responses with GLM and shows that GLM is an excellent alternative to the transformation approach.
Abstract: Generalized linear models (GLMs) may be used as an alternative to traditional methods of analyzing the nonnormal response variables that are frequently encountered in industrial experiments For the several examples of designed experiments with no
TL;DR: It is shown that the proposed model evolves initially as the power law process with shape parameter equal to 2, and then converges asymptotically to the homogeneous Poisson process, the latter being a limiting form of the proposed bounded intensity model.
Abstract: In the failure pattern of repairable equipment subjected to reliability deterioration with operating time, the repeated application of the repair actions sometimes produces a finite bound for the i...
TL;DR: Control schemes that are simple enough for operators to implement and that are robust with respect to the underlying model assumptions are usually sought in the area of process adjustment.
Abstract: Control schemes that are simple enough for operators to implement and that are robust with respect to the underlying model assumptions are usually sought in the area of process adjustment. In the l...
TL;DR: In this paper, the authors address the issue of estimating the Shewhart X control chart limits when the values of the process parameters are not known, and propose a method to estimate the control chart limit when the parameters are unknown.
Abstract: In this paper we address the issue of estimating the Shewhart X control chart limits when the values of the process parameters are not known. Recently it has been shown that in order for the estim...
TL;DR: In this article, the average run length (ARLTL) for multivariate exponentially weighted moving average control charts is calculated for a given set of control charts and the program returns the ARL given values of the shi...
Abstract: We present a computer program that calculates the average run length (ARL) for multivariate exponentially weighted moving average control charts. The program returns the ARL given values of the shi...
TL;DR: This paper investigates the use of the joint estimation (JE) outlier detection method as a statistical process control method for short-run autocorrelated data and shows that JE performs better for AR(1) models when the out-of-control observation is the last observation than for MA( 1) models.
Abstract: The use of joint estimation (JE) outlier detection is evaluated as a statistical process control method for short-run autocorrelated data. The ability of JE to differentiate between four distinct out-of-control observations allows detection of different..
TL;DR: In single-stage screening, inspection is focused directly on the quality characteristic of interest or on a variable correlated with that characteristic as mentioned in this paper, and in two stage screening, the correlated variable is inspected first to determine if the item s..
Abstract: In single-stage screening, inspection is focused directly on the quality characteristic of interest or on a variable correlated with that characteristic. In two-stage screening, the correlated variable is inspected first to determine if the item s..
TL;DR: In this paper, a standard procedure is to identify location effects using ordinary least squares analysis, fit a fit matrix, and study both location and dispersion effects in unreplicated fractional factorial designs.
Abstract: When studying both location and dispersion effects in unreplicated fractional factorial designs, a “standard” procedure is to identify location effects using ordinary least squares analysis, fit a ...
TL;DR: It is shown that the step-down Lenth method is better than the original Lenth Method and the Venter and Steel step- down method and also has a higher individual error rate.
Abstract: Industrial experiments frequently use unreplicated factorial designs, and one method of identifying effects from these experiments is the half-normal plot. One testing method that overcomes the subjectivity of using this graphical method is the Lenth me..
TL;DR: A comprehensive FORTRAN program is presented that can be used to jointly determine the parameters of X̄ charts used in combination with either R or S charts.
Abstract: In this paper we present a comprehensive FORTRAN program that can be used to jointly determine the parameters of X charts used in combination with either R or S charts. The parameters are determined using economic, statistical, or economic- statistical design criteria. The general cost model due to Lorenzen and Vance (1986) is used in economic and economic-statistical designs.