In overcoming the shortcomings of the classical control charts in a short runs production, Quesenberry (1991 & 1995a – d) proposed Q charts for attributes and variables data. An approach to enhance the performance of a variable Q chart based on individual measurements using a robust estimator of scale is proposed. Monte carlo simulations are conducted to show that the proposed robust Q chart is superior to the present Q chart.
Khoo, Michael B. C.
"An Alternative Q Chart Incorporating A Robust Estimator Of Scale,"
Journal of Modern Applied Statistical Methods: Vol. 3
, Article 9.
Available at: http://digitalcommons.wayne.edu/jmasm/vol3/iss1/9