On the verification of the adequacy of methods for determining the depreciation of machinery and equipment items

In the article, a method for estimating the depreciation of machines is considered, in which a parametric model of the dependence of the value of machines on age is first constructed, then the parameters of this model are selected from data on market prices of machines of different ages. Examples are given showing that in some cases this method is incorrect and can lead to the wrong conclusion about the model inadequacy, since the dynamics of depreciation of the machine depends on the conditions of its operation. The author believes that it is possible to avoid such situations by forming a sample of machines operating under approximately the same conditions.