The ISO has developed different standards on usability, and two major categories
can be distinguished:
1. Product-oriented standards (ISO 9126 and ISO 14598)
2. Process-oriented standards (ISO 9241 and ISO 13407)
It should be noted, too, that the properties that software usability takes on might
vary, depending on the target audiences of the software system.
A candidate audience for a software system might include end-users, managers
and software developers. For each of these audiences, usability is defined from a
different viewpoint:
1. For the end-user, software usability is essential because it is a
determinant of performance: an application, which features good
usability, will allow the user to perform the expected task faster and more
efficiently.
2. For managers, usability is a major decision point in selecting a product,
as this decision will have a direct influence on the learnability of the
chosen system, and hence on the productivity of those who use it.