To Back Up Placement References
Use the Backup References options to update the placement of components during the next regeneration, regardless of whether the parent is present or not.
1. To set the option directly, right-click and choose > from the shortcut menu. Alternatively, right-click and choose 
from the shortcut menu, then select the Backup References check box on the Properties tab of the Component Placement tab.
from the shortcut menu, then select the Backup References check box on the Properties tab of the Component Placement tab.2. To backup references for all components in the assembly, click > > > .
3. To remove reference backup, click > > > .