A time sequenced chart with upper and lower control limits on which values of some statistical measure for a series of samples or subgroups are plotted. The chart frequently shows a central line to help detect a trend of plotted values toward either control limit.

A graph of results from sampling the product of a manufacturing process; consists of a horizontal line that represents the expected mean of some characteristic of quality and two lines on either side that represent the extent you are allowed to sample random product deviations.