American Research Journal of Mathematics

Control charts are one of the most common techniques that have been used to observe and control the 

process deviations in the industry. The easiest and the most prevalent method of control charts is the Shewhart Scontrol chart. This method is based on the normal distribution assumption. However, there are a lot of inferences 

in literature that non-normal distributions are much more common than the normal distribution. When the 

normality assumption is not satisfied robust methods are preferred. In this paper, we determine some approaches 

by using robust scale estimators instead of simple standard deviation in order to apply S-control charts. 

Furthermore the performances of these different scale estimators are compared by Monte Carlo simulation study. 

Numerical examples are given at the end of the paper