TY  - JOUR
T1  - Enhancing R Control Chart Performance in Monitoring Process Dispersion using
Scaled Weighted Variance Method for Skewed Populations
AU - Atta, Abdu AU - Shoraim, Majed AU - Yahya, Sharipah AU - Abuzaid, Ali AU - Mahdi, Esam 
JO  - Journal of Engineering and Applied Sciences
VL  - 15
IS  - 6
SP  - 1508
EP  - 1514
PY  - 2020
DA  - 2001/08/19
SN  - 1816-949x
DO  - jeasci.2020.1508.1514
UR  - https://makhillpublications.co/view-article.php?doi=jeasci.2020.1508.1514
KW  - R control chart
KW  -skewed population
KW  -scaled weighted variance method
KW  -SWV-R
KW  -WV-R
KW  -SC-R
AB  - This study improves the performance of R control chart for monitoring process dispersion of skewed
populations using scaled weighted variance method. This control chart, called Scaled Weighted Variance R
control chart (SWV-R) hereafter, the SWV-R control chart compared with Skewness Correction R chart (SC-R)
and Weighted Variance R chart (WV-R) in terms of false alarm. In terms of probability of detection rates the
proposed SWV-R chart is compared with R chart of the exact method, SC-R and WV-R control charts. The
proposed SWV-R control chart reduces to the Shewhart R control chart when the underlying distribution is
symmetric. An illustrative example is given to show how the proposed SWV-R control chart is constructed and
works simulations study show that the proposed SWV-R control chart has the lower false alarm rates than the
SC-R and WV-R control charts, when the underlying distributions are Weibull and gamma. In terms of the
probability of detection rates, the proposed SWV-R control chart is closer to R control chart with the exact
method than WV-R and almost the same performance as SC-R chart.
ER  -