General control charts for attributes

Traditional Shewhart-type control charts ignore the skewness of the plotted statistic. Occasionally, the skewness is too large to be ignored, and in s uch cases the classical Shewhart chart ceases to deliver satisfactory perfo rmance. In this paper, we develop a general framework for constructing Shew hart-like control charts for attributes based on fitting a quantile functio n that preserves all first three moments of the plotted statistic. Furtherm ore, these moments enter explicitly into the formulae for calculating the l imits. To enhance the accuracy of these limits the value of the skewness me asure used in the calculations is inflated by 44%. This inflation rate deli vers accurate control limits for diversely-shaped attribute distributions l ike the binomial, the Poisson, the geometric and the negative binomial. A n ew control chart for the M/M/S queueing model is developed and its performa nce evaluated.