Dimensions

Capability

Ability to complete tasks in reasonable and expected ways, possibly in multiple different ways (flexibility).

Performance

Ability to complete tasks in reasonable time and with reasonable responsiveness

Usability

Ability to complete those tasks reasonably easily, simply and intuitively.

Accessibility

Ability to complete those tasks reasonably well as accessibility-needs users

Security

Ability to reasonably guard against completing or altering tasks as unauthorised users or prevent authorised users from doing so

Reliability

Ability to complete tasks reasonable accurately and when needed