This paper outlines the development of a new human factors assessment tool for the chemical process industry. The approach considers the whole human factors spectrum as the basis for determining the overall quality of human factors in the plant under assessment. The output of the technique is a qualitative report and of quantitative value. From the detailed report, the weak areas in a plant can be detected. The actions to improve these areas can be derived and this not only leads to higher safety but also to higher operation efficiency. The developed computer interface makes the technique especially easy to use, even for non-human factors experts.