v13, 14 and 15:

If you setup 3 step Manufacturing you will have two Transfers created that move inventory, in addition to the Manufacturing Order (job) which consumes raw material inventory and produces finished goods inventory.

• The first Transfer, Stock --> Pre-production, stages raw materials inventory.
• The second Transfer, Post-production -> Stock, puts finished product inventory away.

The first Transfer can be completed in full, or as products are needed for consumption.

• If you need the value of "inventory consumed for Manufacturing Orders still open" you would review the Inventory Report, filtered for the pre-production location.
• If you need the value for EACH open Manufacturing Order, you would review the Product Moves report, filtered for completed moves to the pre-production location.

Once you have the value(s), you can accrue the total(s) to WIP via a Manual Journal Entry. You would then also need to reverse these accruals on the 1st of the following month, since Odoo will decrease the value of raw materials inventory and increase the value of finished goods inventory once the Manufacturing Order is completed, posting through WIP if configured, and you don't want to double count anything.

We don't support (without customization) the traditional concept of WIP - the value of WIP prior to completion is represented by the product(s) in the pre-production location.

We provide the planned cost via the BoM Structure & Cost report (before the MO is completed), and the actual cost via the Manufacturing Order Cost Analysis report (once the MO is completed).