ABSTRACT
Hierarchical task analysis (HTA) was developed at the University of Hull in response to the need to analyze complex tasks, such as those found in the chemical-processing and power-generation industries (Annett et al., 1971). The training of process-control operators was a matter of concern because the time-and-motion methods of task analysis, developed originally for the routine repetitive manual operations used in manufacturing industries, did little justice to the skills needed in modern automated industries, which involve less physical activity combined with a high degree of cognitive skill and knowledge on the part of the operator.
