Reliability analysis of complex systems based on the probability dynamics of subsystem failures and deviation of parameters

Radio-electronic means for various purposes are classified as complex systems and are characterized by a multilevel hierarchical structure in the form of separate units, blocks, and modules. As the system is influenced by a complex of factors in the process of operation, reliability of complex systems functioning depends on the reliability of the system elements and optimal distribution of reliability indicators between the elements of the system. The purpose of this article is to define the reliability requirements for structural elements, taking into account failure rates, and possible gradual changes in parameters of the designed system elements. It is required to ensure the minimum cost for a given level of the system reliability. Systems analysis method, reliability of complex systems theory and probability theory are used in the article with reference to failure rates and changing parameters in the process of operation. This approach provides an opportunity to complement the known methods and to obtain analytical expressions for solving design problems of ensuring the reliability with reference to possible gradual and sudden failures, as well as possible gradual changing in parameters of the designed system elements. It is proposed to apply the developed methodology for defining the reliability requirements for the elements of complex technical systems at the early design stages, when the lack of information makes it impossible to find the optimal distribution of reliability norms for structural elements, providing the minimum total cost of the product. In addition, the method for determining the reliability of structural elements can be used to design highly reliable onboard radio-electronic systems of long-term operation.