Cost of product

Dear Experts ,

I want to undersand allocation methodlogy  management fees, and sales fees to the cost of product.

For example  particular month 500 number production , (Material, labour, other Overhead) i alllocated based on production volume (labour mix ratio). My concern is management fee and sales how can i allocation  based on past history based now allocated to product

Is this system is correct or some other any metod?  becase managemen fee and sales fee is period cost  so i used this method pls explaind