Abstract
Many scientific researches have shown an obvious fact that the quality
control charts with variable sampling schemes are more effective than
the classical ones in improving statistical measures. The average number
of false alarms (ANF), the average number of samples (ANS), the average
number of inspected items (ANI), and the adjusted average time to signal
(AATS) are the most important statistical measures that have always been
attending in the evaluation of control charts. In this paper, a
comprehensive analytical review on the U control chart by the
statistical measures have been explained. For this purpose, different
levels of the possible factors are determined and presented the results
of calculating the statistical measures with the obtained parameters on
the sampling schemes of the U control chart. It is shown that the
variable U control charts are able to improve the effectiveness
statistical, especially for detecting shifts and number of false alarms.