Specification-led design

This paper shows how to combine a substantial part of the product development cycle of interactive devices into a single, co-ordinated approach. Much can be derived automatically from a suitable specification of the interactive device, and it can be derived automatically. Normal product development has a device specified and built, then has its manuals written, then it is used and tested. At this late stage design problems may be identified, but it is now too late: usability studies become academic in so far as the particular product is concerned, since it is already effectively in production. It would be better if the testing and manual writing could rapidly be obtained from the initial specification, before any investment has been made in fabrication. This paper offers a design approach that achieves this, and it shows how the various views of the design can be used help improve each other — for instance, the automatically generated user manual can be fed back to suggest improvements in the design. A microwave cooker is used as a real example. However, this paper provides full and unabridged details of everything it discusses by using Mathematica as a rapid prototyping environment. Any similar device can be analysed in the same way, directly from the paper.