The article discusses the issues of calculating the indicators of the power supply systems’ reliability. The analysis of the existing problem and options for its solution are given. To assess the patterns, the authors proposed a mathematical tool. The method based on the rectangular scores’ technique is adopted as a forecasting method. The development belongs to the class of specialized method-oriented software tools.

Stochastic systems are the systems in which changes are random, the predicted values depend on the probability distribution. An example of a stochastic system is a power system, the operation of which is influenced by many random factors, their analysis and control will give an opportunity to control the safe cycle as well as operation reliability. Improving the efficiency and reliability of the energy system is impossible without the development of special monitoring tools and predicting their state.

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