Posting shipments with item gain or loss

Hi there!!

I'm using Microsoft Dynamics NAV 2013.

I'm currently in a Molasses trading company. As it has been the norm of the process, and since molasses is a liquid matter,  we deliver our product with a different quantity source against delivered. it sometimes occur to have Gain or loss when received by customer.

Is there anyway that NAV can do this process or alike?

here's a sample scenario:

Source weight - The quantity to be deducted from our Inventory, 100 KG

Delivered weight - Actual quantity received by the Customer, 97 KG

Inventory Loss - Inventory lost during delivery, 3 KG

So i would want to post as shipped the above scenario, that would be enetered as

Qty to Ship >  100KG - this will be deducted from my Inventory

Qty Variance > -3KG - this will be Entered as "Inventory Loss" , and will be deducted from the " Quantity to Invoice"

This is a very crucial aspect of our business .... any help will be highly appreciated ... this will  also be factored in our decision to "Go or no Go" with  Dynamics NAV.

Thank you thank you...

more power to you all.