A Mental Workload Control Method Based on Human Performance or Safety Risk.

The prediction of mental workload, as well as the determination of its “redline”, is important in Human System Integration (HSI), as it could save time and resources by detecting problems at the early stages of system design. It is also well-recognized as a key issue in safety risk management. Till now, most of the methods in redline determination hold the perspective of a fixed and absolute threshold. However, human operators are inherently flexible and capable of adopting different strategies to maintain their task performance among a range of mental workload. In the present study, mental workload is considered as a more management than technological issue. An idea of risk-based method is proposed to determine the control line of mental workload. The concept of mental workload intensity instead of amount is proposed to establish a relationship between performance or safety risk and mental workload, so that according to the acceptable risk set by the management/administration, the mental workload control line can be determined. The idea was demonstrated with a case study of maritime tasks. The results show that the output of the proposed method is well consistent with expert judgment.