R Computer Program for The S2 Control Chart

Abstract

To monitor the process variability, the s chart is frequently used. However, the center line of this chart is not an unbiased estimator of the process standard deviation. To avoid this problem, the s² chart may be used instead of the s chart because its center line is an unbiased estimator for the process variance. The paper presents the conceiving of a computer program for the s² chart. The program is developed by means of the R language. After presenting the way in which the program was developed, the paper presents the results obtained after running it.