Comparison of efficiency between classical and modified EWMA control charts using different robust estimators

Quality control is a crucial practice across various industries to ensure that products and services meet specific standards and fulfill customer expectations. Statistical process control (SPC) is a quality control method that utilizes statistical techniques to monitor and manage a process. This stu...

Full description

Bibliographic Details
Main Authors: Mohamed Ali, Nazihah, Mohd Nooh, Murfiqah
Format: Article
Language:English
Published: UPM 2024
Online Access:http://psasir.upm.edu.my/id/eprint/118161/
http://psasir.upm.edu.my/id/eprint/118161/1/118161.pdf
_version_ 1848867447543693312
author Mohamed Ali, Nazihah
Mohd Nooh, Murfiqah
author_facet Mohamed Ali, Nazihah
Mohd Nooh, Murfiqah
author_sort Mohamed Ali, Nazihah
building UPM Institutional Repository
collection Online Access
description Quality control is a crucial practice across various industries to ensure that products and services meet specific standards and fulfill customer expectations. Statistical process control (SPC) is a quality control method that utilizes statistical techniques to monitor and manage a process. This study focuses on EWMA control charts along with robust estimators for monitoring the process mean. The EWMA control chart is particularly effective in detecting small shifts in a process. By implementing SPC, it is usually assumed that the data follows a normal distribution. However, in real-life scenarios, this assumption may not always hold true, and the actual distribution of the data might be unknown. Therefore, in this study, we propose the use of Qn and Biweight Midvariance estimators for constructing EWMA Control Charts. Two data sets, one with heavy skewed and one is slightly skewed, were used in this study. As a result, the EWMA-Qn Control Chart is deemed the most efficient, as it can detect out-of-control points more quickly, regardless of whether the data is heavy skewed or slightly skewed. This method is especially useful in fields such as finance and economics, healthcare and manufacturing where process stability and early detection of shifts are critical. Consequently, the efficiency of the EWMA-Qn Control Chart results in better process monitoring, fewer false alarms, and better decision-making in practical situations, which results in better quality control and utilization of resources in different industries.
first_indexed 2025-11-15T14:36:39Z
format Article
id upm-118161
institution Universiti Putra Malaysia
institution_category Local University
language English
last_indexed 2025-11-15T14:36:39Z
publishDate 2024
publisher UPM
recordtype eprints
repository_type Digital Repository
spelling upm-1181612025-06-26T02:45:59Z http://psasir.upm.edu.my/id/eprint/118161/ Comparison of efficiency between classical and modified EWMA control charts using different robust estimators Mohamed Ali, Nazihah Mohd Nooh, Murfiqah Quality control is a crucial practice across various industries to ensure that products and services meet specific standards and fulfill customer expectations. Statistical process control (SPC) is a quality control method that utilizes statistical techniques to monitor and manage a process. This study focuses on EWMA control charts along with robust estimators for monitoring the process mean. The EWMA control chart is particularly effective in detecting small shifts in a process. By implementing SPC, it is usually assumed that the data follows a normal distribution. However, in real-life scenarios, this assumption may not always hold true, and the actual distribution of the data might be unknown. Therefore, in this study, we propose the use of Qn and Biweight Midvariance estimators for constructing EWMA Control Charts. Two data sets, one with heavy skewed and one is slightly skewed, were used in this study. As a result, the EWMA-Qn Control Chart is deemed the most efficient, as it can detect out-of-control points more quickly, regardless of whether the data is heavy skewed or slightly skewed. This method is especially useful in fields such as finance and economics, healthcare and manufacturing where process stability and early detection of shifts are critical. Consequently, the efficiency of the EWMA-Qn Control Chart results in better process monitoring, fewer false alarms, and better decision-making in practical situations, which results in better quality control and utilization of resources in different industries. UPM 2024 Article PeerReviewed text en http://psasir.upm.edu.my/id/eprint/118161/1/118161.pdf Mohamed Ali, Nazihah and Mohd Nooh, Murfiqah (2024) Comparison of efficiency between classical and modified EWMA control charts using different robust estimators. Menemui Matematik, 47 (1). pp. 16-27. ISSN 2231-7023 https://persama.org.my/images/Menemui_Matematik/2025/MMv471_16_27.pdf
spellingShingle Mohamed Ali, Nazihah
Mohd Nooh, Murfiqah
Comparison of efficiency between classical and modified EWMA control charts using different robust estimators
title Comparison of efficiency between classical and modified EWMA control charts using different robust estimators
title_full Comparison of efficiency between classical and modified EWMA control charts using different robust estimators
title_fullStr Comparison of efficiency between classical and modified EWMA control charts using different robust estimators
title_full_unstemmed Comparison of efficiency between classical and modified EWMA control charts using different robust estimators
title_short Comparison of efficiency between classical and modified EWMA control charts using different robust estimators
title_sort comparison of efficiency between classical and modified ewma control charts using different robust estimators
url http://psasir.upm.edu.my/id/eprint/118161/
http://psasir.upm.edu.my/id/eprint/118161/
http://psasir.upm.edu.my/id/eprint/118161/1/118161.pdf