ABSTRACT
There are a few situations in which it is possible to design a product or workstation for a single user: bespoke tailoring, haute couture, the customised seats used by racing drivers and the workstations of astronauts are examples. These are all essentially luxury goods. For a very small number of especially unfortunate individuals, the luxury of custom design becomes a necessity. The physical characteristics of the very severely disabled are so diverse that aids to mobility and independence must often be made for the individual concerned. However, in the great majority of real-world design problems our concern will be with a population of users. The product must therefore be designed to be adequate for all the population, include adjustability or be produced in a range of sizes.
