FIXED APPLICATION
You make a fixed application when you specify that the cost of an inventory increase should apply to a specific inventory decrease, or vice versa. The fixed application affects the remaining quantities of the entries, but the fixed application also reverses the exact cost of the original entry that you are applying to, or from.
To make a fixed application, you use the Appl.-to Item Entry field or the Appl.-from Item Entry field in the document lines to specify the item ledger entry that you want the transaction line to apply to, or from. For example, you might make a fixed application when you want to create a cost application that specifies that a sales return should apply to a specific sales shipment to reverse the cost of the sales shipment. In this case, Microsoft Dynamics NAV ignores the costing method and applies the inventory decrease, or increase, for a sales return, to the item ledger entry that you specify. The advantage of making a fixed application is that the cost of the original transaction is passed to the new transaction.