Human factors engineers complain that their contribution to interactive system design is typically sought late, that is following system implementation. Software engineers, in contrast, complain that the human factors contributions to system design are neither timely, appropriate nor implementable. One solution to this problem is for human factors contributions to be integrated with those of software engineering, that is presented at a time and in a form that contributes directly to system development, and in particular to the design of the user interface. This paper proposed how structured methods, in the form of Jackson System Development (JSD), might be used to integrate human factors generally into system development.