Bringing a process under control
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.
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Open the file tutorials\Copper.xlsx.
The worksheet is open with some of the data hidden. We will use the additional hidden data later in this tutorial.
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On the Analyse-it ribbon tab, in the
Statistical Analyses group, click Process Control, and then click
Xbar-R.
The analysis task pane opens.
- In the Process drop-down list, select Copper.
- In the Sample size group, select the Subgroup by identifier variable option.
- In the Id drop-down list, select Date.
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Click Calculate.
The results are calculated and the analysis report opens.
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.

- There is a point dated the 03/01 on the R chart with high variation.
- There are 2 further points dated the 11/01 and 13/02 on the Xbar chart.