摘要:

In some production processes and administrative processes, the occurrence of certain events is best described by a geometric distribution. Control charts are developed for the total number of events and for the average number of events in a fixed number of units. Computer simulation is used to demonstrate the consequences of applying a standardc-chart oru-chart when the geometric model is appropriate. In a simulated example, construction of a control chart based upon a geometric distribution reduces the false alarm rate from 9.6% to 0.9%. In conclusion, two examples illustrating the applicability of these charts are presented.

ISSN:0022-4065    

DOI:10.1080/00224065.1992.12015229

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

Minute accumulating analysis (MAA) is Taguchi's method for analyzing life test data from designed experiments. Motivated by comparing survival curves, MAA analyzes sequences of binary data generated from the life test data. This paper explains MAA and exposes numerous pitfalls caused by ignoring or misusing information provided by the data. Examples using real and synthetic data and a simulation study demonstrate that MAA can detect spurious effects, miss real effects, and reverse the order of factor importance. Consequently, MAA cannot be recommended. Standard techniques for analyzing reliability data, which correctly handle life test data, provide a valid and flexible alternative.

ISSN:0022-4065    

DOI:10.1080/00224065.1992.12015230

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

The purpose of this paper is to propose a new control chart, the double samplingX̅chart, which is the counterpart to double sampling plans. This procedure offers better statistical efficiency (in terms of the average run length) than the ShewhartX̅chart, without increased sampling. Alternatively, the procedure can be used to reduce the sampling without reducing the statistical efficiency. The properties (probability of a signal, average run length, average sample size, etc.) of the double samplingX̅chart are studied, and it is compared with variable sampling interval Shewhart charts, EWMA charts, and CUSUM charts. The double sampling chart depends on five parameters, and therefore, there is a great deal of flexibility in designing the chart. Tables are provided to aid in the choice of these parameters.

ISSN:0022-4065    

DOI:10.1080/00224065.1992.12015231

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

Whenpcorrelated process characteristics are being measured simultaneously, often individual observations are initially collected. The process data are monitored and special causes of variation are identified in order to establish control and to obtain a“clean”reference sample to use as a basis in determining the control limits for future observations. One common method of constructing multivariate control charts is based on Hotelling'sT2statistic. Currently, when a process is in the start-up stage and only individual observations are available, approximateFand chi-square distributions are used to construct the necessary multivariate control limits. These approximations are conservative in this situation. This article presents an exact method, based on the beta distribution, for constructing multivariate control limits at the start-up stage. An example from the chemical industry illustrates that this procedure is an improvement over the approximate techniques, especially when the number of subgroups is small.

ISSN:0022-4065    

DOI:10.1080/00224065.1992.12015232

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

A quantitative measure of linearity of a P-P probability plot is the square of the correlation coefficient of points on the plot. This statistic aids in the assessment of goodness of fit of a hypothesized distribution. A computer program is presented for computing thepvalue of this statistic when testing the goodness of fit of a normal, a Gumbel, or an exponential distribution. The program can also construct a normal, a Gumbel, or an exponential P-P probability plot.

ISSN:0022-4065    

DOI:10.1080/00224065.1992.12015233

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

ISSN:0022-4065    

DOI:10.1080/00224065.1992.12015234

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

ISSN:0022-4065    

DOI:10.1080/00224065.1992.12015235

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

ISSN:0022-4065    

DOI:10.1080/00224065.1992.12015236

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

ISSN:0022-4065    

DOI:10.1080/00224065.1992.12015238

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

ISSN:0022-4065    

DOI:10.1080/00224065.1992.12015239

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor