Reliability Analysis of Man-Machine Systems Considering Imperfect Error Coverage Model

The reliability of man-machine systems refers to the reliability of the performance of both machine subsystems and human subsystems. As the reliability of machine subsystems have significantly improved, the reliability of man-machine systems increasingly depends on human reliability. However, most man-machine system reliability studies assume that once a human error occurs, it will inevitably lead to system or subsystem failure. Our analysis reveals that there are automatic recovery mechanisms in man-machine systems similar to those in machine components, which can detect and correct human errors. Additionally, the coverage of human errors is imperfect. This paper proposes an Imperfect Error Coverage Model of Human Error (IECM), in which the outcomes of human errors are categorized into three possibilities: transient recovery, covered errors, and uncovered errors. Transient recovery refers to human errors that can be corrected by the operator on their own within a short period of time and without adverse effects on the system. Covered errors refer to human errors that can be detected and corrected by other components, systems, or humans. Uncovered errors refer to human errors that are not successfully detected and corrected by other components, systems, or humans. This paper further proposes a quantitative method for calculating the unreliability of man-machine systems. Experimental results demonstrate that, compared to traditional models, the proposed method can analyze the unreliability of man-machine systems more accurately, thereby improving the accuracy of reliability assessments for such systems.