Dismantle (take to pieces) finished goods

Hi,

I am FI consultant. I have a requiremen in MM module.

Business is doing Trading Electronics Goods.

If they found any Piece is not good (damaged) they want to do it into pieces (make it into spare parts). Pieces (spare parts) having separate materials.

Finished Goods ---> Spare parts

Quantity ➖ ---> Quantity ➕

In this case no dismentaling charges. (zero charges)

Please guide me how can it mapped in MM goods movement. This over FI point view also.

Thanks

Partha