Control charts usually present a graphic display of process stability and/or instability with time, from which the you can determine mean and standard deviation.

Multivariate quality characteristics are often monitored using a single statistic or a few statistics. However, it is difficult to determine the causes of an out-of-control signal based on a few ...

Control chart- a time-ordered plot of sample statistics, used to distinguish between random and nonrandom variability Control limits- the dividing lines between random and nonrandom deviations from ...

Key Takeaways: The three sigma limit is statistical data within three standard deviations from a mean. Three sigma limits set the upper and lower control limits in statistical quality control charts.