A Human-machine Interface Evaluation Method Based on Balancing Principles

Human factors principles provide foundation for guidelines of various codes and standards in designing Human-Machine Interfaces (HMIs). Also in Nuclear Power Plants (NPPs), a lot of guidelines from various codes and standard and derived from various research and development projects are available for designing Main Control Room (MCR) HMIs. However it is not easy to optimize and balance a great deal of information sources provided in NPP MCRs in a systematic manner. In this study, a balancing principle for HMI design optimization is proposed to be used in the HMI design of complex supervisory tasks in NPPs. The balancing principle is that a HMI element (e.g., an indicator or a push button) should be designed according to its importance. Design and importance attributes in the HMI design are recognized to apply the balancing principle, respectively. Two measures, Design preference to Importance Ratio (DIR) and Balancing Index (BI), based on the balancing principle are developed. The proposed principle and measures are then successfully applied to an HMI design evaluation. By using the proposed measures, unbalanced design features could be found out and reasonable recommendation could be made based on the evaluation results. As a further study, more extensive attention should be paid to considerations on how to find out and apply various design and importance attributes in the HMI design.