This function is started by AutoCAD if a BOM has already been created, and further info points or item numbers were inserted in the drawing at a later point in time, and you want the BOM to reflect these changes.

However, this will only occur if the system variable POP_GENFV_SYSVAR = 1 has been defined in the AutoCAD configuration settings.

A dialog box appears where, if you press ‘Yes’, you can specify that the BOM should be updated to include the up-to-date information in the drawing. If you press ‘No’, the BOM will remain unchanged.

One special feature in this dialog box is the "Update from external database" option. This option is useful if you have made changes to a standard parts database. If you activate this checkbox, the corresponding data records are re-imported from the database, the info points and item numbers in the drawing are updated, and the existing BOM is updated.

Regardless of the POP_GENFV_SYSVAR system variables defined in AutoCAD, the Power Update dialog box will appear automatically when you exit the drawing if any changes have been made to item numbers in your drawing (new item numbers were added, information was changed for an item number, etc.). You can decide at this point whether or not you want to update the BOM.