System documentation and system design: a good reason for designing the manual first

The usability of systems has become an increasingly important issue in the design and implementation of systems. Usability can be defined in terms of four basic criteria: effectiveness, learnability, flexibility and attitude. The author argues for user centred design and suggests that a major benefit to the design process can be obtained if system documentation is treated as a component of user centred design and as such `put to work´ in the design of the system. The following stages should be adopted: the data obtained in the user requirements analysis (the requirements report) should be written as a prototype user manual and made available to users immediately for comments and evaluation, and user comments should be used to re-write the manual (iteration); the three stage design documents and screen design should be incorporated into the user manual and users asked to comment as part of the evaluation process and again iteration should take place; and when the first prototype is available for `hands-on´ evaluation the user manual should be evaluated with the software-any changes made to the software should also be reflected in the manual