Due to the rapid change of technology along with advanced data-collection systems, the simultaneous monitoring of two or more quality characteristics (or variables) is necessary. Multivariate Statistical Process Control (SPC) charts are able to effectively detect process disturbances. However, when a disturbance in a multivariate process is triggered by a multivariate SPC chart, process personn...

Multivariate control charts such as Hotelling`s T^ 2 and X^ 2 are commonly used for monitoring several related quality characteristics. These control charts use correlation structure that exists between quality characteristics in an attempt to improve monitoring. The purpose of this article is to discuss some issues related to the G chart proposed by Levinson et al. [9] for detecting shifts in ...

multivariate control charts such as hotelling`s t^ 2 and x^ 2 are commonly used for monitoring several related quality characteristics. these control charts use correlation structure that exists between quality characteristics in an attempt to improve monitoring. the purpose of this article is to discuss some issues related to the g chart proposed by levinson et al. [9] for detecting shifts in ...

While researchers and practitioners may seamlessly develop methods of detecting outliers in control charts under a univariate setup, screening multivariate pose serious challenges. In this study, we propose robust chart based on the Stahel-Donoho estimator (SDRE), whilst process parameters are estimated from phase-I. Through intensive Monte-Carlo simulation, study presents how estimation presen...

Hotelling T 2 control chart not only reflects the correla-tions between different quality characteristics but also has good efficiency on monitoring multivariate in production process. A new alternative was constructed after original products data are processed by using exponentially weighted moving average for cumulating failure effects because is ineffective detecting minimal mean deviations....

The world of education is one aspect life that has been affected by Covid-19, so on March 17, 2020 the Ministry Education and Culture issued a Circular regarding online learning. Andalas University Mathematics Undergraduate Study Program study programs at also implements an learning process. In this study, evaluation will be carried out based Statistics I II courses in odd semester 2019/2020 ev...