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 


auto_join=True, index=True, required=True,
        help="Location where the system will stock the finished products.")
    partner_id = fields.Many2one(
        'res.partner', 'Destination Address ',
        states={'done': [('readonly', True)]},
        help="Optional address where goods are to be delivered, specifically used for allotment")
    move_dest_ids = fields.Many2many(
        'stock.move', 'stock_move_move_rel', 'move_orig_id', 'move_dest_id', 'Destination Moves',
        copy=False,
        help="Optional: next stock move when chaining them")
    move_orig_ids = fields.Many2many(
        'stock.move', 'stock_move_move_rel', 'move_dest_id', 'move_orig_id', 'Original Move',
        copy=False,
        help="Optional: previous stock move when chaining them")
    picking_id = fields.Many2one('stock.picking', 'Transfer Reference', index=True, states={'done': [('readonly', True)]})
    picking_partner_id = fields.Many2one('res.partner', 'Transfer Destination Address', related='picking_id.partner_id')
    note = fields.Text('Notes')
    state = fields.Selection([
        ('draft', 'New'), ('cancel', 'Cancelled'),
        ('waiting', 'Waiting Another Move'),
        ('confirmed', 'Waiting Availability'),
        ('partially_available', 'Partially Available'),
        ('assigned', 'Available'),
        ('done', 'Done')], string='Status',
        copy=False, default='draft', index=True, readonly=True,
        help="* New: When the stock move is created and not yet confirmed.\n"
             "* Waiting Another Move: This state can be seen when a move is waiting for another one, for example in a chained flow.\n"
             "* Waiting Availability: This state is reached when the procurement resolution is not straight forward. It may need the scheduler to run, a component to be manufactured...\n"
             "* Available: When products are reserved, it is set to \'Available\'.\n"
             "* Done: When the shipment is processed, the state is \'Done\'.")