An improvement for HTA based on cognitive process

The task analysis is the chief work of human factor, and assists analyst to deeper understand and describe the system and the human in it. The context of the task analysis is to describe human performance in a particular task or scenario and to break down tasks or scenarios into the required individual task steps based on the necessary interaction between the human and the machine. Cognitive task analysis is used to describe the cognitive performance of human what can't be observed and the mental processes used by the human in the system when they complete the tasks. In recent years, a range of Human Factors (HF) methods which can be applied in system safety design and evaluation has been studied. HTA (Hierarchical task analysis) is a widely used task analysis technique of human factors. Its advantages is that it can provide for the analyst with desired goals and a deeper level of understanding of the target task through both by describing the task steps and one specific operation. However, the information provided by HTA is mainly descriptive rather than analytical and HTA itself cannot provide the cognitive analysis process. In this paper, Information Hierarchical Disposal-Decision Modal (IHDDM) and a new way through integrating the cognitive task process of human into the traditional HTA analysis process (CP-HTA) are presented. The new task analysis technique can provide a much more complete understanding of human-machine interaction task analysis process. At last, a case is presented to describe how to apply the technique in practice.