Outside Process to Purchase Requisition/Order

Hi,

I need help or opinion on how to achieve the result.

Here is the scenario:

I have a BOM item with WIP, with this each process is tag as outside process.

from each process we have material(s) involve this material(s) would be charge to the contractor doing the process thru OM. In other words we would sell the raw materials to the contractor and let them pay. (not a conventional manufacturing practice)

My problem here is the management wanted to PO this item with corresponding process, which the price consist of the material and labor(Process price attached to WIP) plus certain percentage automatically reflect on the PO line.