Hi, 

Let´s say we place orders for a car from a supplier. The total cost for a car is 30 usd, consisting of 10 usd for the hood and 5 usd per wheel.  

The car is a purchase structure.

We place an order for a full car from supplier A, in order for supplier A to build the car we must supply them the wheels. The wheels we purchase from another supplier, supplier B.

Now when we place a Purchase order, PO for a car, a customer order, CO is generated for us to supply supplier A with 4 wheels. This seems to be called component parts. 

When the car is delivered to us we receive an invoice for 10 usd. since we have provided the wheels ourselves. 

But in inventory transaction history the received value of the car is 30 usd. 

Now in part cost 10

Level 1 has a car with “level unit cost” of 30 usd, and since level 2 consist of 4 wheels x 5 usd, The total cost to next level is 50 usd. The wheels are being calculated double. 

I don´t know how to best handle this in order for the component parts to only be calculated once?