2 Tukey and EWMA control charts
Tukey and EWMA control charts are used to monitor the parameters of a quality characteristic of a quality characteristic of interest, say Y. Let Y1 , Y2 , Y3 ……… , Yn be independent and identically distributed observations (measured over time) having mean u0 in a univariate setup. Based on this information, the description of Tukey and EWMA design is given below.