Current human factors input to system development is effected through methods, tools and guidelines. Although the input prompts the consideration of human factors concerns during system design, reports have highlighted inadequacies with respect to the scope, granularity, format and timing of the contributions, e.g. Smith, 1986; Chapanis and Burdurka, 1990; Sutcliffe, 1989; etc. The thesis argues that such problems are obviated if design needs of both Software Engineering and Human Factors are appropriately represented within an overall system design cycle. Intersecting concerns may then be identified for explicit accommodation by the design agenda. To derive an overall design cycle, current conceptions for the individual disciplines should be examined. Since these conceptions are expressed at a lower level as methods, an overall design cycle may be instantiated more specifically by integrating compatible methods from the two disciplines. Methodological integration is desirable as design inter-dependencies and roles may be defined explicitly. More effective inter-disciplinary communication may also accrue from the use of a common set of notations. Methodological integration is facilitated if the design scope, process and notation of individual methods are well defined. Such characteristics are found in a class of Software Engineering methods commonly referred to as structured analysis and design methods. Unfortunately, the same are not currently to be found for human factors since its methods are generally unstructured and focus only on later design stages. 1 Thus, a pre-requisite for integration is the derivation of a reasonably complete and structured human factors method. Since well developed Software Engineering methods already exist, it would be appropriate (for the purposes of methodological integration) to structure human factors methods around specific structured analysis and design methods. The undertaking is exemplified by the present research for the Jackson System Development method. In other words, the scope of the thesis comprises the derivation, test and integration of a structured human factors method with the Jackson System Development method. In conclusion, the research contributes to the Human Factors discipline in two respects. Firstly, it informs the research community on how similar work with other structured analysis and design methods may be set up. Secondly, it offers designers an extended Jackson System Development method that facilitates the incorporation of human factors during system development
