The execution of a task involves an individual’s cognitive commitment, enabling them to solve problems and face challenges. This cognitive engagement depends, among other factors, on the level of dedication to the task. Additionally, this commitment is also related to mental fatigue, which can be caused or not by the task itself. Mental fatigue is characterized by a decrease in concentration capacity, reduced performance, and mental exhaustion. In this work, we aim to investigate the application of electroencephalogram as a tool to assess fatigue and engagement in an industrial environment. The overall objective is to evaluate the mental engagement of heavy machinery operators in a simulated mining environment, correlating it with mental fatigue and productive performance. Among the various metrics described in the literature, three measures of mental fatigue and two measures of engagement were analyzed. We intend to observe which measures are most suitable for this task at hand and whether they can identify patterns consistent with the literature. In the end, we found that the fatigue metric described by the \(\frac{\alpha +\theta }{\beta }\) ratio was not sufficient to adequately represent the inversely proportional relationship with mental engagement.