In Chapter One, the ‘too-little-too-late’ problem of human factors contribution was identified. The problem highlights the importance of earlier and wider human factors involvement in system development. Although additional areas of human factors contribution have been identified, the problem could not be simply or directly rectified, since the contributions map poorly onto the design support requirements of each stage of system development. In particular, existing human factors design processes were observed to be largely implicit, and its design techniques provide only a narrow coverage of the system design cycle.

To solve this problem, a more explicit and complete conception of human factors design with respect to system development, is required. Such a conception would facilitate the identification of more specific requirements for human factors support. On the basis of the requirements, existing means of human factors contribution may then be recruited and extended as appropriate.