Define Access to Actual Costing/Material Ledger
In this activity, you create the
costing keys for valuation with actual costs of goods
manufactured. You define how the system calls up the periodic
allocation prices/actual cost estimates from the 
Material Ledger by maintaining costing keys.
Further Notes
When your sales quantities in CO-PA are valuated using periodic allocation prices/actual cost estimates from the Material Ledger, this typically occurs at the period end during revaluation.