Impacted versions:
11.0

I don't know if it is an issue, but I think is strange.

`product_qty` is in unit of `product` : https://github.com/odoo/odoo/blob/11.0/addons/stock/models/stock_move.py#L240
`reserved_availability` is in unit of `stock.move` : https://github.com/odoo/odoo/blob/11.0/addons/stock/models/stock_move.py#L295

`move.product_qty - move.reserved_availability` seems to have no sens, no ?

https://github.com/odoo/odoo/blob/11.0/addons/stock/models/stock_move.py#L915
https://github.com/odoo/odoo/blob/11.0/addons/stock/models/stock_move.py#L917
https://github.com/odoo/odoo/blob/11.0/addons/stock/models/stock_move.py#L924

thank for your answer

@jco-odoo 
@alnslang 


addons/stock/tests/test_move.py
'product_id': self.product3.id,
            'product_uom': self.uom_unit.id,
            'product_uom_qty': 1.0,
        })
        move3._action_confirm()
        move3._action_assign()
        move3.move_line_ids.qty_done = 1
        move3._action_done()
        
        self.env['stock.move.line'].create({
            'move_id': move3.id,
            'product_id': move3.product_id.id,
            'qty_done': 1,
            'product_uom_id': move3.product_uom.id,
            'location_id': move3.location_id.id,
            'location_dest_id': move3.location_dest_id.id,
            'lot_id': lot2.id,
        })
        quants = self.env['stock.quant'].search([
            ('location_id.usage', '=', 'internal'),
            ('product_id', '=', self.product3.id),
        ])
        self.assertEqual(len(quants), 2)
        from odoo.fields import Datetime
        for quant in quants:
            if quant.lot_id == lot1:
                self.assertEqual(quant.in_date, Datetime.to_string(initial_in_date_lot1))
            elif quant.lot_id == lot2:
                self.assertEqual(quant.in_date, initial_in_date_lot2)
    def test_transit_1(self):