5.1 Introduction

Task analysis is the name given to a range of techniques that can be used to examine the ways that humans undertake particular tasks. Some of these techniques focus directly upon task performance, whilst others consider how specific features of the task, such as the interfaces, operating procedures, team organisation or training, can influence task performance. Thus, task analysis techniques can be used either to ensure that new systems are designed in a way that assists the users to undertake their tasks safely and effectively, or to identify specific task-related features that could be improved in existing systems. The general family of tools known as Task Analysis can contribute substantially valuable methodologies. This chapter should be read in conjunction with the additional information concerning error and its quantification provided in Chapter 8 of this book.

The task analysis process is essentially about understanding the requirements of a person who might undertake a task and then assessing whether the task and the environment, or situation, in which the task is undertaken is designed in a manner that meets these requirements. At the highest level these requirements can often be met by developing a set of task descriptions that can then be used to identify the basic interface requirements. However, task performance seldom depends solely upon the interfaces, because there are many other influences upon performance, such as training, team organisation, communications, workload, time pressure or environmental factors, that can all influence the way in which human...