Commitment Cost & Inventory Cost

We are in process of implementing Project Manufacturing, Project Costing & Project Billing.

When we make a PO, we attach Project Number & Task, it comes as a commitment in Project Status Inquiry.

When we make a Payables Invoice against the PO, the commitment cost gets transferred to Actual Cost.

What will happen if we use the same item which we have purchased in manufacturing process and we transfer WIP cost to Projects?

Will the item cost get transfer to Projects once at the time of AP Invoice and second at the time of WIP transfer to Project.