Reliability analysis in man-machine systems

The authors present a comprehensive evaluation of the reliability of a technical system with a human operator (a man-machine system, MMS). In the first part the paper, technical systems are analyzed with respect to their dependability. The quantification of reliability in technical systems results from the applied models and is based on the calculation of relevant indicators. The detection of a system´s critical elements is ensured mainly by quantitative reliability analyses. The next section of the article contains a discussion of man-machine systems, where the human factor plays an essential and often dominant role within the entire process of interaction between the operator and the technical system. Quantitative evaluation of human reliability is currently based on the total probabilistic safety analysis (PSA) of the whole MMS system. The analysis also comprises human reliability assessment (HRA). In this context, the paper presents the best known and most widely used HRA methods.