A Cusum for a Scale Parameter
- 1 October 1981
- journal article
- research article
- Published by Taylor & Francis in Journal of Quality Technology
- Vol. 13 (4) , 228-231
- https://doi.org/10.1080/00224065.1981.11978762
Abstract
Standard cusum procedures are available for controlling the mean of a process. However, in many industrial applications it is important to control the process variability as well. This article presents a technique for employing the same cusum procedure used for the mean for controlling the variance. The technique is based on cusumming |Xi/σ|1/2, which is very nearly normally distributed if X is N(O, σ2). If the process has a nonzero unknown mean, then the same technique may be applied with Xi replaced by the difference between successive observations.Keywords
This publication has 1 reference indexed in Scilit:
- Theoretical StatisticsPublished by Springer Nature ,1974