Currently if there are any existing quantity of a sub assembly for a BOM product, this will not be taken into account for the BOM product buildable quantity calculations, and it will only calculate how many can be made with the buildable quantity of the sub-assembly components, not of the existing premade components.
It would be good to enhance this to include the current available stock for the sub-assembly products to give a more accurate figure for how many BOM products can be built using pre-existing sub-assemblies and buildable sub-assemblies.