THE CHANGING NATURE OF TASK ANALYSIS

Task analysis (TA) has been one of the primary tools of human factors from the very beginning. This chapter begins by defining TA as the study of who should do what, why it is necessary and finally how and when it should be done. The demand for TA only arose when the use of technology became more pronounced or even indispensable, especially when tools changed from being simple to being complex. All TA methods make use of the principle of decomposition, of breaking something into its constituent parts, to reason about activities and how they are related and organized. There are two fundamentally different approaches to TA and task description. They are structural tasks and functional tasks. The main development is the use of functional rather than structural analyses to account for the dynamic couplings among the functions (or tasks) necessary to accomplish an activity.