First of all, the operation efficie

First of all, the operation efficiency of fixed assets in the early use is high, and the income obtained from the use of assets is relatively high. According to the principle of matching income with expenses, the depreciation amount to be raised in the early stage should be relatively large. Next, the total cost that fixed assets USES includes depreciation cost and repair cost two parts. Usually in the later use of fixed assets repair costs will gradually increase. And the depreciation expense of the method of average life is invariable in each period, this caused total expense to increase gradually, do not accord with the principle of matching.Thirdly, the average life method only considers the utilization degree and intensity of fixed assets, ignoring the relationship between the use and depletion degree of fixed assets and the relationship between work efficiency. Finally, the average age method does not take into account the effect of invisible loss.