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 


'product_uom': self.uom_unit.id,
            'product_uom_qty': 5.0,
        })
        move2._action_confirm()
        move2._action_assign()
        move2.move_line_ids.qty_done = 5
        move2._action_done()
        self.assertEqual(self.product1.qty_available, 5.0)
        self.assertEqual(self.product1.with_context(company_owned=True).qty_available, 10.0)
    def test_edit_initial_demand_1(self):
        """ Increase initial demand once everything is reserved and check if
        the existing move_line is updated.
        """
        move1 = self.env['stock.move'].create({
            'name': 'test_transit_1',
            'location_id': self.supplier_location.id,
            'location_dest_id': self.stock_location.id,
            'product_id': self.product1.id,
            'product_uom': self.uom_unit.id,
            'product_uom_qty': 10.0,
            'picking_type_id': self.env.ref('stock.picking_type_in').id,
        })
        move1._action_confirm()
        move1._action_assign()
        move1.product_uom_qty = 15
        
        self.assertEqual(move1.state, 'assigned')
        self.assertEqual(move1.product_uom_qty, 15)
        self.assertEqual(len(move1.move_line_ids), 1)
    def test_edit_initial_demand_2(self):