Cost incurred in production

Dear all,

For example, while production, to produce 10 parent items need 10 child items A and 20 child items B.

So if the production is perfect, then the price of 1 parent item is 1 price of A + 2 price of B. But, if some child items are being defected, we need addition 5 child items A and 6 child items B. Therefore, the price per 1 parent item is increase by (5 items A/ 10) + (6 items B/10).

What function in SAP b1 9.2 help me allocate this?

Best wishes,

QuangLV