An accounting policies should be consistently applied once adopted. Otherwise the comparability of financial statements from one period to another is not fairly stated. This change of deprecitation method is regarded as a change in accounting policy and the amount so affected should be quantified and be adjusted and be fully disclosed in the current year's financial statements. The users of the financial statements could then know its impact on the profit and the value of the assets as well. Moreover, the fair values of the assets are quite an important issue, any impairment should be adjusted in the accounts so as to make the financial statement exhibit a true and fair view.