Quantity based overhead

Hi,

In the costing sheet, we've got working the percentage overhead .

But now we want to use Quantity based overhead, I've defined a quantity based overhead like this:

Valid from, valid to.

CO Area

Overhead Area

Amount of overhead -->100

Unit-->Euro

Per--> 1

Unit--> unit

I've change the costing sheet replacing the old Overhead rate (percentage overhead) with the percentage overhead.

The problem is that when after costing run(Ck11n),it is taking material cost from BOM,activities cost from master recipe,but overhead cost is not appearing.

Do I have to change anything more?

King regards