The article deals with a complex technical system of variable structure (СTS VS), which has: complexity, multicomponent, many quantitative and qualitative parameters; the complexity of experimental studies, the risks of hazardous situations and the catastrophic nature of their consequences; the uniqueness of
the modes and conditions of the systems functioning. The peculiarities of such systems determine the specifics of their analysis and modeling: the impossibility of creating and using general analytical models;
the complexity of ensuring the reliability of modeling due to the uniqueness, insufficient data on hazardous and emergency modes of operation of the СTS VS substation. These features make it possible to substantiate the advisability of combining various approaches and methods for constructing and composing
a unified model of the system from the models of its individual components. The proposed principle of
constructing systems significantly expands the possibilities of managing the process of functioning of the
СTS VS due to the flexible use of the useful properties of each of the structures, depending on the internal
state of the system and changing external conditions. A typical example of СTS VS is the air supply system of coal mines. The configuration of this system must constantly change, adapting both to a change in
the structure and volumes of the faces themselves, and in connection with a possible change in the parameters of technical devices for pumping air into mines (up to their complete failure).
The aim of the work is to develop a universal analytical and statistical model for calculating reliability
indicators and a comprehensive assessment of complex technical systems of variable structure.
The novelty lies in the fact that a universal analytical and statistical model has been developed for determining the boundary values of reliability indicators and calculating a pessimistic and optimistic assessment, which differs in that it takes into account the features of the functioning of non-recoverable and
recoverable, redundant and non-redundant technical systems in case of failures and restorations of elements during the influence of various random parameters, which makes it possible to calculate the reliability of the functioning of the СTS VS of the substation and evaluate the effectiveness of the application
of measures of structural redundancy.
