Επίδραση της εκτίμησης των παραμέτρων στις ιδιότητες των διαγραμμάτων ελέγχου για τη μέση τιμή
Ψαράκης, Γεώργιος Ν.
In Phase I control charts, control limits are calculated using estimates of unknown parameters of the distribution of the attribute of interest, arising from historical reference samples. In Phase II control charts, statistical functions of new samples are compared with the control chart limits to draw a conclusion around whether the manufacturing process operates in a stable condition or not. The majority of studies conducted on the performance of control charts in Phase II based on the assumption that statistical control parameters of the distribution of the characteristic of interest are known and equal to the estimated parameter values obtained in Phase I. However, when the estimated parameters are used in place of actual parameter values, the performance of control chart will be different from that of the corresponding control charts with known parameters due to the variability of estimated parameters. The main purpose of the dissertation is to study the effect of parameter estimation on the properties of control charts of Phase II, for monitoring the mean of a manufacturing process.