If I understand the Parameter correct: The parameter prevents the cost calculation until the production order is ended (and there is no way to correct it again). In my opinion, it would be helpful to skip it until the production is reported as finished. In that case you have a chance to make corrections to the PO. Wouldn't it be better to have a parameter where you can choose until when the cost calculation is skipped? - Change label to "Defer updates of cost calculation until" - Allow the following settings: "Never"/"Report as Finsihed"/"Ended" There also should be a manual way of updating the cost calculation to see the impact of corrections made or to see the actual costs even parameter is set to "Report as finsihed" or "Ended".