Mathematical model of differentiation of tractor reliability indicators and its application for given conditions of an agricultural enterprise

The article presents the results of a theoretical study on optimizing the life cycle costs of complex technical objects, using agricultural tractors as an example. A mathematical model has been developed to differentiate tractor reliability indicators under specific conditions of use. The developed model supports the cost optimization of tractors and similar high-complexity mechanical systems. An example of applying the mathematical model is provided, along with recommendations for an agricultural enterprise to enhance the profitability of tractor operations. Calculations have shown that the optimal indicator of the mean time between failures for complexity group 3 tractors of traction class 5-7 is the optimum value of the objective function within the 480-740 engine hours range. At the same time, the monitoring data of operational indicators indicate that the actual operating time for K744P2 tractors is 215 engine hours, and for Buhler Versatile 2375 tractors, it is 865 engine hours. Thus, the use of Buhler Versatile 2375 tractors from the point of view of cost optimization is 12.7% more economically advantageous than the use of K744P2 tractors in these conditions. However, the use of Buhler Versatile 2375 tractors also does not correspond to the optimum of the objective function, and further optimization by another 13.8% is possible here.