4 Who are the users?

This section reveals that ‘users’ can include a wide variety of people – not just the final purchasers or consumers of a product. The section also makes the case for strong user representation in the design process.

Of course, it is not only me who uses the various products in my home; other people use them as well, both members of the family and visitors. Sometimes the range of users of a product, and their different needs, can be diverse. And in addition to the obvious or intended users there is a variety of people who have to interact with the product in various ways at different times, such as the people who make it or assemble it.

CYCLE OF USE AND THE USERS OF A PRODUCT

To manufacture the product people have to shape material, drill holes in components, and so on. During assembly people have to pick up the different pieces and put them together. During installation the product has to be transported, fitted into place, connections made and performance tested perhaps. The product has to be maintained and repaired by people during its working life. Finally, product components are often recycled or reprocessed; the different materials have to be separated and this is usually done by hand.

All these stages involve people in one way or another and so, ideally, a full usability evaluation would examine not only how well the product suited the capabilities, limitations and requirements of the user in the sense of the consumer, but all the other people who interact with it as well. For instance, how many times have you tried to repair something, only to find that you do not have the right tool, or the interior parts are inaccessible? These problems are widespread and they do not affect just the amateur at home. Most mechanics or service technicians will tell you stories about designs that make their jobs harder.

Manufacturing requirements can often override even needs. That is because manufacturing and assembly difficulties cost money through lost time, faulty products, accidents and worker dissatisfaction. I had a car once on which it was almost impossible to change one of the spark plugs because it was virtually out of reach behind other components, even when the special flexible plug spanner provided by the manufacturer was used. Of course, it was no trouble to insert the plugs before the distributor, carburettor, air filter, gear-shift connector, choke cable and so forth had been bolted on. In other words, the design is compatible with the requirements of one set of users (assemblers) at one stage in the product life cycle but not with the requirements of other users (service mechanics) at a later stage.