Usability engineering

Usability engineering is a subset of human factors that is specific to computer science and is concerned with the question of how to design software that is easy to use. It is closely related to the field of human-computer interaction and industrial design. The term "usability engineering" (UE) (in contrast to other names of the discipline, like interaction design or user experience design) tends to describe a pragmatic approach to user interface design which emphasizes empirical methods and operational definitions of user requirements for tools. Extending as far as International Organisation for Standardisation-approved definitions usability is considered a context-dependent agreement of the effectiveness, efficiency and satisfaction with which specific users should be able to perform tasks. Advocates of this approach engage in task analysis, then prototype interface designs and conduct usability tests. On the basis of such tests, the technology is (ideally) re-designed or (occasionally) the operational targets for user performance are revised.

Usability Engineering, like all forms of engineering, needs to be based on a solid foundation of requirements.Usability Engineering needs to take into account the different usability requirements of different groups of users, different tasks, different content chunks, and different existing tools. The inter-connectedness of these elements is illustrated in Figure 1.

Figure 1. Inputs into the Development of a successful computer application

 Usability Engineering, like all forms of engineering, involves applying specialized processes throughout a systems development life cycle. Usability engineering needs to be highly iterative, as illustrated in Figure 2.

Figure 2 Iteration within and between usability engineering life cycle stages