This module helps to reduce the cost of FG as follows:

1) Set by-product valuation method as Standard Cost and input cost on product form of the by-product.
2) Standard Cost of by-product will be reduced from overall manufacturing cost of FG through customization.
3) By-products quantity will be updated on given cost through default odoo functionality.

Bill of Material (BoM):

The by-products are set on the BoM of a specific product. Two additional columns are created through customization that shows the cost and the "per unit manufactured" cost of the by-product as can be seen in the picture below.

Manufacturing Order (MO):

When the Manufacturing Order of that BOM is created and processed then on confirming the MO, the quantity of Finished Good as well as the by-products is received in stock from the product location.

Cost Analysis:

Odoo default Cost Analysis report is also customized. The Finished Good manufactured is received at the average unit cost, if the costing method is set as AVCO or at Standard cost if the costing method is set as Standard Price. The By-Products are received on standard cost as set on the product form in Odoo.
The cost of raw materials is reduced by the value of total By-Products produced, as can be seen in the picture below.