The article deals with the issues of computer modeling of the formation of error in forecasting the state of the object of control. To analyze the process of error formation in the implementation of forecasting methods, the main stages of solving this problem are highlighted. The structural and functional organization of forecasting the state of the object of control is presented. A model of error generation in solving the forecasting problem in an automated technical condition control system has been developed. The simulation was performed according to the developed algorithm for estimating errors in the implementation of the method of individual forecasting. Based on the simulation results, analytical dependences of the random component of the prediction error on the length of the prehistory taken into account and the noise level of the ideal trend are established.