A capability assessment provides a quick and simple way to evaluate products or concepts by comparing the capability levels required to use them. The use of any product can be broken down into a series of activities, where each activity forms part of a wider product interaction via a task or lifecycle analysis.

For each activity, demands are made on the user. These demands can be rated according to a series of capability scales. At their simplest, these scales range from low to high, where low and high provide a relative measure when one product or scale is compared to another.

Although these scale measurements are crude, they are easy to use as an initial tool and can provide an effective visual comparison between alternative products or concepts. Reducing capability demands (while achieving the same features or functions) should lead to a more satisfying product that can be used by a wider percentage of the population.