Shevtsov, V., Lavrov, A., Izmailov, A., and lobachevskii, Y., "Formation of Quantitative and Age Structure of Tractor Park in the Conditions of Limitation of Resources of Agricultural Production," SAE Technical Paper 2015-26-0147, 2015, doi:10.4271/2015-26-0147.
A feature of the present state of the Russian agricultural industry is that productive resources (tractor pool, arable land area and number of workers involved) are diminishing and the reduction does not have a quantified value. In the prevailing conditions of limited resources, agricultural enterprises are forced to operate tractors beyond their amortization periods on a massive scale, which results in an unpredictable service life.This situation calls for an assessment of the optimal composition of the tractor pool in terms of number and age. By way of a solution to this problem, the given article presents a methodological approach as to the analysis of two opposing factors. On the one hand, it takes into account the fact that the use of tractors beyond their depreciation periods leads to increased costs of their operation and further yield losses related to the poor technical condition factor, which is proportional to the number of tractors with expired depreciation periods. On the other hand, it must take account of the loss of profit resulting from the reduction of the total size of the tractor pool, reduction of arable land area, diminishing number of workers, the shortfall in the harvest due to diminishing arable land area, not observing the time limits of agricultural activities and crop rotation, curtailing the process cycles and all of the losses that should be proportional to the deficit in the number of tractors due to more being scrapped than purchased.The technique developed was used to determine optimal number and age composition of a tractor pool of agricultural enterprises of the Russian Federation as established by the data of the Federal State Statistics Service. The optimization criterion is minimization of aggregate costs. Its value is determined by plotting dependences of budget overrun for the use of tractors with expired depreciation periods and lost profit. After plotting these dependences, the aggregate costs curve is determined by summation. Calculations performed using this method made it possible to determine optimal number and age composition of the tractor pool.