Create my field '' servicios_ids''  in my fsm.order model which relates to the product.product model

Model fsm.order field:
          servicios_ids = fields.One2many('product.product', "service_ids",string="Servicios")  

Model product.product field:
      service_ids = fields.Many2one('fsm.order', string='Servicios')

When I add a line to my one2many field, the same product that I added is created again and this causes my products in inventory to be duplicated.

 any ideas?