Because of the time-value of money, there is a significant tax benefit to the company for using accelerated depreciation methods.
Sum-of-Years' Digits is a depreciation method that results in a more accelerated write-off than straight line, but less than declining-balance method.
Other systems allow depreciation expense over some life using some depreciation method or percentage.
The depreciation method can be straight-line, reducing balance, sum of the digits, economic, or indeed any other, so long as the periodic charge is fair.
Such as managers electing to use different depreciation method allowing lower profits at the start and higher profits towards the end.
Numerous depreciation methods available to automate depreciation routines.
In subsequent periods, the historical cost along with taxation-driven depreciation methods does not help managers determine their current operational cost factors.
The depreciation method and recoverable amount is reviewed at least annually (IAS16.61).
If you used the computer less than 50 percent of the time for business, you have to use an alternative depreciation method, generally a straight line recovery over five years.
It was also said that the cumulative effect on prior years of a change in depreciation method reduced net income by $175 million in the latest year.