Interpreting Control Charts
Control charts fall into two
categories: Variable and Attribute Control Charts.
are data that can be measured on a continuous scale such as a
thermometer, a weighing scale, or a tape rule.
Attribute data are
data that are counted, for example, as good or defective, as
possessing or not possessing a particular characteristic.
of control chart you use will depend on the type of data you are
It is always preferable to use variable data.
Variable data will provide better information about the process than
Additionally, variable data require fewer samples
to draw meaningful conclusions.