Reliability analysis of machine operators employed in thermal spraying technology in the context of human resource management using the extended TESEO and HEART

This paper aims to develop a model for assessing the reliability of thermal spray machine operators using the Technica Empirica Stima Errori Operatori (TESEO) and Human Error Assessment and Reduction Technique (HEART), which have been expanded to include four additional factors. The results of this model support human resources management processes, particularly in competence development, training planning, and risk reduction. The paper characterizes the thermal spray machine operator’s workstation and presents the specific work environment, taking into account the technical and organizational conditions that influence the technological process. Occupational hazards were identified and risk assessed using the Risk Score method. A human reliability assessment model based on the HEART and TESEO was then developed. To increase the accuracy of the assessment under thermal spraying process conditions, the model was expanded to include four original factors: the stability of technological process parameters, the intensity of physical impacts, the variability of material and substrate properties, and the dynamics of control and operational decision-making. The results indicate that incorporating additional factors allows for a more comprehensive assessment of the probability of operator error, better reflecting the specific nature of the thermal spraying process. The developed model can serve as a tool to support activities in human resources management, especially in training planning, competence development, and occupational safety improvement.