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
'picking_id': picking.id,
            'product_id': self.product1.id,
            'product_uom': self.uom_unit.id,
            'product_uom_qty': 1,
        })
        product3_move = self.env['stock.move'].create({
            'name': 'product3_move',
            'location_id': self.supplier_location.id,
            'location_dest_id': self.stock_location.id,
            'picking_id': picking.id,
            'product_id': self.product3.id,
            'product_uom': self.uom_unit.id,
            'product_uom_qty': 1,
        })
        picking.action_confirm()
        picking.action_assign()
        with self.assertRaises(UserError):
            picking.button_validate()
        product3_move.move_line_ids[0].qty_done = 1
        with self.assertRaises(UserError):
            picking.button_validate()
        product3_move.move_line_ids[0].lot_name = '271828'
        action = picking.button_validate()  
        self.assertTrue(isinstance(action, dict), 'Should open backorder wizard')
        self.assertEqual(action.get('res_model'), 'stock.backorder.confirmation')
        product3_move.move_line_ids[0].qty_done = 2
        action = picking.button_validate()  
        self.assertTrue(isinstance(action, dict), 'Should open overprocessing wizard')
        self.assertEqual(action.get('res_model'), 'stock.overprocessed.transfer')
    def test_immediate_validate_7(self):