QAD 2017 Enterprise Edition > User Guides > Periodic Costing > Periodic Costing Adjustments > Best Practices for Adjustment
  
Best Practices for Adjustment
If you enter an adjustment and save it, then discover that you made an error, you can only edit adjustments in PC WO Adjustment, so ensure that figures are accurate before making an adjustment. There are utilities and reports that help you find adjustment errors; see Delete/Archive Periodic Costing Data.
You cannot make a unit cost adjustment that is less than zero.
When you delete an order, Periodic Costing leaves the cost at 0 (zero) for the items on the order during the calculation and continues running the calculation.
Do not add figures for overhead during total cost adjustment; overhead is figured at unit cost adjustment.
When you include overhead at total cost adjustment, the overhead does not impact the receiving costs since receipts are considered first; however, it does impact the issue. For overhead, you want to apply receiving, either PO or work order receiving, but, for total cost adjustment, the receiving is applied afterwards. Since the total cost comes afterward, you are recalculating unit cost with overhead for which you do not have beginning balance, so there is a receiving gap that does not support the overhead.
Also, when overhead is figured in the middle of the period, the system does not apply it to the receipts in the beginning of the period.