Process control charts identify special-causes of variation that need to eliminated to
bring the process under control, so the results are predictable and can be used to determine
the ability of a process to meet customer specifications.
The worksheet is open with some of the data hidden. We will use the
additional hidden data later in this tutorial.
During the installation period of a new automated colorimeter for controlling the
copper content in the plating process control charts can be used to identify
special-causes of variation that need to eliminated to make the process perform
predictably. The Xbar and R charts plot the mean and range of the copper
concentration in the plating pool respectively.