Hi Jack
If your dep key is based on explicit % then that becomes your rate of depreciation
if your dep key is based on total useful life, then the % is derived from total useful life. Eg- if TUL is 10 years, rate of depreciation is 10%
if your key is based on Rem. Useful life, then Sap calculates the rate of depreciation at every period end based on RUL. ,
In Aw01n you can click on one of the icons and it shows you a detailed explanation of how the depreciation was calculated
Ajay M