On Performance of Two-Parameter Gompertz-Based X-bar Control Charts
Loading...
Date
2020
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Hindawi
Abstract
In this paper, two methods of control chart were proposed to monitor the process based on the two-parameter Gompertz distribution. .e proposed methods are the Gompertz Shewhart approach and Gompertz skewness correction method. A simulation study was conducted to compare the performance of the proposed chart with that of the skewness correction approach for various sample sizes. Furthermore, real-life data on thickness of paint on refrigerators which are nonnormal data that have
attributes of a Gompertz distribution were used to illustrate the proposed control chart. .e coverage probability (CP), control limit interval (CLI), and average run length (ARL) were used to measure the performance of the two methods. It was found that the Gompertz exact method where the control limits are calculated through the percentiles of the underline distribution has the highest coverage probability, while the Gompertz Shewhart approach and Gompertz skewness correction method have the least CLI and ARL. Hence, the two-parameter Gompertz-based methods would detect out-of-control faster for Gompertz-based charts.