Specification-led design for interface simulation, collecting use-data, interactive help, writing manuals, analysis, etc

The paper shows how easy it is to combine a substantial part of the product development cycle of interactive devices into a single, coordinated approach. The approach is so efficient that it is effectively concurrent engineering. We show that the definition of a device, its simulation, its usability analysis, and its user manuals (and interactive help, if required), can all be worked on directly and efficiently in a suitable design environment. Importantly, our approach only needs one definition of the device; thus changes-as occur during iterative design and product revision-immediately and automatically affect all parts of the development process. To illustrate our approach we have used the symbolic mathematical system, Mathematica (S. Wolfram, 1996). Mathematica is sufficiently powerful that everything described in the paper is completely and fully specified. It should be noted that many popular system development environments, especially those aimed at providing visual realism, are inappropriate because they never explicitly `know´ what the device specification is, and none of the automatic benefits discussed here can be obtained. As an example, we use the definition of a microwave cooker, as given in J. Sharp´s paper (1998). As a deliberate decision, we used Sharp´s exact definition, to try and emphasise the generality of the approach