ABSTRACT
Why would someone want to use a control chart? Essentially, a control chart is used to separate random from non-random variation; to indicate when variation is stable and when it is not. This leads to three interlinked approaches:
1. To analyze data in order to understand it and the process involved 2. To aid in attempts to reduce variation (to indicate what course of action is
called for and which attempted improvements worked and did not work) 3. To control the process on a minute-by-minute or batch-by-batch basis
For control chart purposes, data can be divided into variables and attributes. In essence, they can be described as follows:
Variables.
