In JMP 5.x, excluded rows are ignored in control chart calculations.
In JMP 6.0, excluded rows are included in the calculation of the moving ranges for IR charts, similar to how SAS handles excluded points.
In JMP 6.0.2 and later, a preference setting for handling excluded columns has been added. From the menu, select [File] > [Preferences] to display the Preferences window, and in the [Platform] panel, in the preferences for control charts, there is [Use Excluded Points on MR]. By default, it is off, and excluded points are ignored. (It is the same as the processing in JMP 5.x.) When it is on, excluded points are also included in the moving range control chart.
