An assessment is the administration of a sequence of activities to determine the capabilities of an individual. The various KEY evaluations measure a person's abilities in lifting (at three identified heights), pushing, pulling, carrying with the right, carrying with the left, as well as identifying specific tolerances for sitting, standing and walking. KEY also identifies endurances for non-weighted activities such as bending, squatting, crawling and kneeling.

The results are not only used to determine a worker’s safe working levels for returning to work following injury, but also for purposes of job placement, injury prevention programs and rehabilitation decisions.