In the Process Capability launch window, the options in this section enable you to assign each variable in the Y, Process list a subgroup ID column or a constant subgroup size.
1. Select a variable or variables in the Y, Process list.
2. Select Subgroup ID Column from the Subgroup with options.
3. Select a subgroup ID column in the Select Columns list.
4. Click Nest Subgroup ID Column.
The subgroup ID column appears in brackets to the right of the variable names in the Y, Process list.
1. Select a variable or variables in the Y, Process list.
2. Select Constant Subgroup Size from the Subgroup with options.
3. Enter the subgroup size next to Set Constant Subgroup Size.
4. Click Subgroup by Size.
The subgroup size appears in brackets to the right of the variable names in the Y, Process list.
Nest Subgroup ID Column
(Available when you select Subgroup ID Column.) Assigns a column that you select from the Select Columns list to define the subgroups for the selected Y, Process columns.
Subgroup by Size
(Available when you select Constant Subgroup Size.) Assigns the subgroup size that you specify in the Set Constant Subgroup Size box to define the subgroups for the selected Y, Process columns.
Set Constant Subgroup Size
(Available when you select Constant Subgroup Size.) Specify the constant subgroup size for the selected Y, Process columns. You need to assign this value using Subgroup by Size.
Within-Subgroup Variation Statistic
(Available when Process Subgrouping is used.) Specifies if the within-subgroup estimate of standard deviation is calculated using standard deviations or ranges.
Calculate Between-and-Within Capability
(Available when Process Subgrouping is used.) Specifies that the between-and-within subgroup estimate of the standard deviation should be used in the capability analysis. Use this option when there is both between and within sample variation. For an example of data that contains both types of variation, see “Example of a Three Way Control Chart”.