The aim of this paper was to understand the influence of cognitive and emotional-motivational aspects of task complexity on workers performances in high-technology driven drilling activity in a deep mine. Data was collected by observing and video recording miners’ engaged in two separate production drilling activities, using two Boomers simultaneously. Based on the analysis, it is found that the workers encounter cognitive challenges in their ability to process information marked on rock surfaces for the positioning of the boomers, resulting in added complexity to their drilling tasks. The workers’ were also found to have issues with the quality of their designed job environment, and which emotional-motivational challenge also added to their tasks complexity. It is concluded that by understanding the emerging cognitive and emotional-motivational aspects of task complexities, future design processes of a friendly and performance enhancing work environments and technologies could evolve for efficient and effective human work.