I use VA05 to run open sales order to work out the back log. However, make sure that your open sales order list is correct. Open sales order should only list sales orders that have not been invoiced. For AU10, it took us nearly 12 months to clear off all incorrect open sales orders. Previously, we had sales orders that were completely invoiced but still listed as open and I had to manually eliminate them from my final open sales order list (please see the attached example of our Sept Sales report file)