And today. Depreciation Accounting. Depreciation--definition.
Depreciation is the process by which the cost of property, plant & equipment is either matched with revenues, or allocated to the periods of benefit. As an allocation process, the primary emphasis is on income measurement and reporting, and secondarily on the valuation of depreciable assets for SFP purposes.
For the SYD method, the rate declines linearly and the base remains constant, so the depreciation expense declines linearly.
In the DB method, the depreciation rate is unchanged, but the base declines exponentially. The resulting depreciation expense declines exponentially.