Its not impossible and you have varying ways of doing this.
Easy methods,
create both charts call up the layout tool from the editor menu and put them on the same page. It does not overlay but you can display them side by side or one above the other.
They are I charts, so we can use a Time series. Go to the time series plot, choose multiple, enter both columns. Job done
The data must be in seperate columns to display correctly.
You can add reference lines to put the control limits on, if by some lucky chance they share the same values for UCL and LCL.
Complex method.
This wont work for I-MR only I charts. The following only works for graphs that can update, but you can use if for anything.
Create both I charts.
Select one chart and edit the background and data colour to be none. For easy aligning of the charts delete the control limits lables and centre line labels.
Select the chart that you have not fixed the background as none. Go to editor and copy command language.
Open up notepad and paste this into notepad
Select the second chart, the one with the background and data region set to none. Go to Editor and copy command language.
Paste this under the commands for the first chart.
At the top of the notepad file before the graph commands type LAYOUT, at the end after all commands type ENDLAYOUT.
Copy all the text and in Minitab press CTRL+L to call up the command line editor. Paste the text in and run the commands
The graphs will be overlaid. But they probably dont line up very nicely.
You can add a DATA subcommand to specify data region positions within each set of commands for a chart.
For example
Data 0.1615 0.9531 0.1797 0.9115;
added amongst the graph commands specifies the size and location of the data region. You can fix this to the same value for both charts to ensure the data regions are the same.
You probabaly want to remove the Y axis labels as well on each chart to tidy it up.
Its possible to then save these commands in a macro for future use as well.
Personally I would run the time series plot unless it was really essential to use the I chart.
