Temporal requirements and the human computer interface : not just an afterthought

Time plays an intrinsic part in the human computer interface. We argue that temporal issues must be recognised as fundamental to the interface, not relegated to the status of quality requirements. If we treat time as being relevant only to quality we run the risk of identifying related requirements too late in the RE process for them to be properly incorporated. We recognise that it is neither practical nor desirable to impose strict temporal requirements on the performance of every system, and we focus our attention on systems where the satisfaction of such requirements cannot be guaranteed, such as Web-based applications where some delays are inevitable. Using the Web browser as an example of additional non-temporal functional requirements before it is too late.