In manufacturing module  

class mrp_production 

'move_created_ids': fields.one2many('stock.move', 'production_id', 'Products to Produce',

domain=[('state', 'not in', ('done', 'cancel'))], readonly=False),                              is working

but i cant add same like 

'mrp_product': fields.one2many('mrp.product', 'production_id', 'mrp products',readonly=False),

what is the problem ? is any extra features class mrp_production ?