Perpetual versus Periodic Costing Methods

Each Inventory Organization must select a perpetual costing method from the four available methods.  These methods are perpetual in that transactions are costed during the accounting period.  Optionally, periodic costing methods can recost the transactions without disturbing the original cost.  Although preliminary periodic costing can be run during the period, the final periodic costing is run after the accounting period close.
Periodic Costing

Periodic Average Costing (PAC) and Incremental LIFO costing are optional cost methods.
One or both can be cost all the transactions in a period without disturbing the perpetual costs.  Each periodic costing method can create one or more user defined cost types.  The cost types may differ from each other by calendar, rates, or status (open period).