In this FICO Configuration activity you are able to define base methods. Base methods are independent of the chart of depreciation.
IMG Path: Financial Accounting (New) -> Asset Accounting -> Depreciation -> Valuation Methods -> Depreciation Key -> Calculation Methods -> Define Base Methods
Tables: T090NR, T090NRT
On the main screen you will be able to see all defined base methods.
On double click or new entry you could go detailed view.