SUMMARY
Purpose. The scientific work is aimed to: 1) study the indicators and criteria for evaluating the influence of human factor on failure-free operation of freight cars; 2) theoretically describe the probabilistic model of the human factor role during the maintenance and repair of freight cars according to technical state; 3) consider the model of situation development for the case of a critical defect of the freight car unit taking into account the human factor. Methodology. In order to achieve this purpose, the methodological approaches were considered: 1) to evaluation of the reliability indicators in the system «man – freight car» during maintenance and repair; 2) to evaluation of the level of traffic safety in case of transition from the existing system of maintenance and repair of freight cars to the system according to technical state. The model of the situation development for the case of a critical defect of the freight car unit with the consideration of the human factor was described. Findings. The approach to the evaluation of risk indicators of potential failures of freight cars is given. The probability of occurrence of negative events (risks) and possible economic damage from their manifestation were taken as the indicators. In the developed model of situation development for the case of a critical defect of the freight car unit with the consideration of the human factor, three possible states are shown: workable and limited workable, unworkable and emergency. Each initial state is characterized by the development of events, which is associated with designers` errors, with defects during manufacture of parts and units, with human factor. Originality. It is proposed to consider the value of the failure probability, which is related to the human factor, as a certain proportion of the overall probability of failure of the system «man – freight car». The interpretation of Harrington's desirability function for the case of application to freight cars is given. During maintenance and repair, it is suggested to introduce an indicator that characterizes the observance of the technology of use of maintenance services for freight cars, taking into account the human factor. Practical value. Based on the conducted research it is possible to evaluate the influence of the human factor on the maintenance and repair of freight cars. According to the developed model of situation development for the case of a critical defect it is possible to determine the critical level of the defect of the freight car unit taking into account the human factor to limit the risk of an accident or transport event.