MUF CONTROL CHARTS AND LEMUF CALCULATIONS USING AN AUTOCORRELATION TECHNIQUE

Standard deviations based on monthly MUFs which are to be used for MUF control charts and LEMUFs should be corrected for the correlation between successive MUFs. The first order autoregression equation as given by Jenkins and Watts in \"Spectral Analysis and its Applications\" has been applied to MUF data for estimating standard deviation. The construction and interpretation of MUF control charts using the standard deviation corrected for autocorrelation is presented. LEMUFs based on these standard deviation estimates are discussed. Procedures for detecting and omitting deviant results are also presented.