Algorithmic capabilities of Bayesian estimation of the reliability of functional blocks of a complex software and hardware system

Objective. The objective of this study is to develop mechanisms for obtaining real-time assessments of the reliability of functional units within software-hardware systems. Method. Drawing on systems analysis, reliability theory, and the theory of stochastic modeling, the proposed mechanisms for calculating the probability of failure-free operation are demonstrated through their application to monitoring the functional units of onboard equipment in aircraft. Result. A method for calculating the functional reliability of onboard equipment is established. A Bayesian approach is proposed, which involves calculating the theoretical probability of safe operation for onboard equipment by estimating the lower one-sided confidence bounds for each functional unit at a specified confidence level. Algorithms are presented for estimating time-series parameters; these are based on determining conditional expected values of the probability of safe operation, which are optimal in the mean-square sense. A mathematically consistent framework for assessing operational risk in aircraft - applicable even in cases with limited statistical data or incomplete testing - is proposed. Conclusion. Unlike traditional approaches used for flight safety monitoring in civil aviation, the Bayesian estimation method reduces both the cost of testing and the time required to obtain functional reliability assessments for onboard equipment. The proposed approach benefits from the simplicity of its input data, while the use of mathematical programming tools allows for the refinement of expert-based decisions—even with small sample sizes - well before the results from benchmark or test flights become available. Integrating intelligent safety devices equipped with the proposed software into functional units is a key factor in ensuring the reliable operation of an aircraft's onboard systems.