Range of application of theoretical laws distributions

The article discusses the borders of application of theoretical laws of distribution of failures of technical systems. Machine failures are random and in most the independent events, which have a significant scattering range.A substantiation technique of processing information provides a reliable assessment of the technical excellence of the machines. The theoretical law of distribution expresses the regularity of changing the reliability indicators of the entire set of machines. The coefficient of variation is one of the mathematical criteria for preselecting the function approximation of experienced data. A change in the distribution density of random values from the degree of their scatter was established. Influence of coefficient of variation on value of asymmetry and excess of normal law is shown. Regularities of change of relative error of interpretation of initial information are revealed. Based on the estimation of the calculation error, the diapason of application of theoretical distributions of random variables is justified.