Costing issue when choice costing method is FIFO

Question

Impacted versions: v11 and v12

Steps to reproduce:

Install sale_management, stock, account_accountant and purchase. Enable "Lots & Serial Numbers" from Inventory/Configuration/Setting. Create a product tracking with lot then change the 'Costing Method' field on the category to 'FIFO' and change the 'Inventory Valuation' filed on the category to 'Automated'. Create a purchase order with the above product with unit price equal to 10 then receive the product with "lot-1" as lot name. Duplicate the above purchase order, change the unit price to 3 then receive the product with "lot-2" as lot name. Create a sale order with qty = 1 from for the above product and deliver from "lot-2". Reviewing the stock valuation entry created from the delivery order above, the value of journal entry is 10.

Expected behavior: Value of the stock valuation entry should be 3 as we have delivered from “lot-2”.

Answer 1

Expected behavior: Value of the stock valuation entry should be 3 as we have delivered from “lot-2”.

I don't thing this is the expected behavior. Product costing method: FIFO (First in first out). Let's see how the in moves are organized:

in move1 -> lot-1 (validated first) with price 10
in move2 -> lot-2 (validated second) with price 3

In terms of FIFO, selected move for costing of the outgoing product is move1, as it was first in. So the selected costing is 10.

The selected lot has nothing to do with the costing, in case FIFO costing, system will look for and track quantities of incoming moves and get costing information from the first one.