The following bullets summarize the use of excluded and hidden samples in control chart builder:
• Excluded subgroups are not used in the calculations of control limits, and appear on the chart as dimmed points by default. If the Show Excluded Region option is not selected, the points for the excluded subgroups do not appear in the chart, are treated as missing in Tests for Special Causes, and are not included in the count of points for Tests for Special Causes.
• Hidden observations are used in the calculations of control limits, but do not appear in the chart.
• Rows that are both hidden and excluded are included in the count of points for Tests for Special Causes when the Test Excluded Subgroups option is selected. An excluded row can be labeled with a special cause flag. A hidden point cannot be labeled. If the flag for a Tests for Special Causes test is on a hidden point, it will not appear in the chart.
• For partially excluded subgroups, if one or more observations within a subgroup is excluded, and at least one observation within the subgroup is included, the excluded observation is not included in the calculations of either the point statistic or the limits.
• Checks for negative and non-integer data happen on the entire data (even excluded values).
• Tests apply to all excluded subgroups only when the Test Excluded Subgroups option is selected.