You can copy production BOMs. Make sure that the BOM you copy to is not certified. The item lines in the BOM you are copying to are replaced by the lines in the BOM you are copying from.
Open the 
Production
BOM window.
Select or create the BOM you want to copy to. (To create a BOM, on the Menu Bar, click Edit, Insert New. Fill in the No. field.)
Click Functions, Copy BOM.
Select the BOM to copy from.
Click OK to copy the lines into the current BOM.
Close the window.
Copying Production BOM Versions by Using Copy BOM Version Functions
Copying Production BOM Versions by Using the Copy BOM Header Function