In
SolidWorks preferences, select the Copy Relationship check box in the Checkin section. For details on setting preferences, see Setting Preferences.
During Save, if the top SolidWorks Drawing has more than one Parts List, then a message is displayed indicating that the multiple Parts-Lists exists and that the existing Parts-Lists must be consolidated to a single Parts-List.
If you are saving a design with assembly at the root, then PartList is not transferred because the drawing is not saved when assembly is at the root.
When there are multiple drawings connected to the same design, then the first drawing with a Part List is considered. All other drawings connected to the design are ignored.