After generating BOM in Drafting if we edit any part in the assembly after releasing the drawing to the shop floor (Rework) then if all those modified parts can be segregated as one group in newly created BOM which again need to release to shop floor then any department can easily identify what are the parts modified and which individual part need to be reworked
If small assemble it is easy to identify for Shop floor people . But, in case of it is huge assembly it will take lot of time to search complete BOM which parts are modified and at the same time there may be chance of searching error
By including this option we can reduce lot of Pain to end user and can reduce time & errors