orden_servicio/models/sale_order.py

# -*- coding: utf-8 -*-
# License, author and contributors information in:
# __openerp__.py file at the root folder of this module.

from openerp import models, fields, api

class SaleOrder(models.Model):
    _inherit = 'sale.order'

    @api.multi
    def open_order_service_form(self):
        order_service_obj = self.env['orden.servicio']
        order_service_vals = {
            'sale_order_id': self.id,  # Pasa el ID del Pedido de Venta a la Orden de Servicio
            'partner_id': self.partner_id,
            # Otros campos relacionados con la Orden de Servicio que deseas establecer
        }
        order_service = order_service_obj.create(order_service_vals)

        view_id = self.env.ref('orden_servicio.form_orden_servicio_mejorado').id
        return {
            'name': 'Orden de Servicio',
            'view_type': 'form',
            'view_mode': 'form',
            'res_model': 'orden.servicio',
            'res_id': order_service.id,
            'view_id': [view_id],
            'type': 'ir.actions.act_window',
        }