Managing usability requirements in interactive systems development

Usability requirements have a crucial impact on the process of developing interactive systems. Translating usability requirements into an effective interaction design that supports effective interaction styles is a considerable challenge to interaction designers. During the development process, usability specialists need to select proper usability evaluation techniques in order to ensure that the interactive system under development meets its usability specifications. To set the usability requirements for any interactive system designers need to be able to articulate the attributes of usability that will make or break the si,stems. Translating usability, attributes into usability requirements, and managing usability activities is the focus of this paper: how to identify usability attributes? Why they lend to differ from one definition to another? Why identifying them is crucial to the success of the interactive system? Finally, how managing usability requirements can lead to an effective user-centred development approach?.