The Shared Traceability columns are used to match data records from different retrieval groups that share the traceability information displayed in the table. For example, in the table shown below, each retrieval group has a data record with the date/time stamp close to "12/7/99 8:30:00" and the Lot number "120799".
However, fields that are not displayed – traceability or date/time – are not used to match data records. For example, in the table shown below, each retrieval group in the first row may have different values for the undisplayed traceability fields – Shift, Machine, Cavity, Department, and Operator.
If a data record does not match the displayed traceability values of a data record from a different retrieval group, it is still displayed on the Multiple Data Table, as in the following example:
Defining the "Shared Traceability" columns
By default, Date/Time is the only column displayed under the Shared Traceability heading. However, you can configure SPC to display different traceability columns by following the steps below:
Generate a Multiple Data Table.
Click the Options menu, and then click Select Display Columns.
In the Separate rows for each unique combination of list, select the check box of each field you want to display on the Multiple Data Table.
Keep in mind that the fields you select will be used to match data records from different retrieval groups.
If you clear all the check boxes in this list, the data records from different retrieval groups will be matched by count (first subgroup retrieved for each retrieval group, second subgroup retrieved for each retrieval group, etc.), and the Shared Traceability column will be removed from the Multiple Data Table.
The Multiple Data Table will display the traceability and date/time columns you select in the order shown on this screen. You can modify the order in which these columns are displayed.
To move an item up the list, click the row containing the item and then click the up 
button.
To move an item down the list, click the row containing the item and then click the down 
button.
If you want to save your selections as new default settings on this workstation, select the Save as default check box.
After selecting the fields and the order in which to display them, click OK.
Defining how date/time stamps are matched
When matching the date/time stamps of data records from different retrieval groups, SPC actually matches date/time stamps that are close to each other.
By default, date/time stamps within 10 seconds of each other can be considered identical. However, you can change this time period for date/time matches by adding the mdt_datespan= setting to your Cms.ini file. Set this option equal to the number of seconds within which two date/time stamps can be considered identical.
The date/time stamp displayed on each row of a Multiple Data Table is the actual date/time stamp of the first (leftmost) data subgroup displayed on that row. The date/time stamps of the remaining subgroups displayed on that row may match exactly, or they may fall within the specified time period (10 seconds or the number of seconds set in Cms.ini).
More:
Retrieval group columns in a Multiple Data Table
Sort order of rows in a Multiple Data Table
Right-click menu and Options menu for a Multiple Data Table