The objective of the present overview is to establish a conceptual foundation for a detailed stage-wise account of the method in Chapters Four to Six.

General Characteristics of the Human Factors Method

The primary focus of the method is on design specification because a literature survey indicated that current human factors contributions are well established at later stages of system development, e.g. human factors evaluation after design implementation. In contrast, human factors contributions to design specification are generally inadequate and implicit. Since the recruitment of human factors contributions is traditionally late, the discovery of design errors is also delayed. As a result, the required modifications are costly and difficult to implement (see Chapter One). Thus, greater emphasis is placed on ensuring human factors contributions to design specification. In this context, a participative followed by consultative design role for human factors contribution is envisaged at system specification and implementation respectively. During the latter stage, existing techniques for human factors evaluation may be recruited to support the method. An overview of the method follows.

The method is structured into three phases, each of which comprises a number of design stages (Figure 2-8 is reproduced overleaf for reference).