An individual aircraft maintenance engineer can usually easily identify what work must be done. It is more difficult to assess how that work translates into a workload. A workload is generally defined as the level of stimulation caused by a task that is exerted on a person, and can be separated into physical workload and mental workload. Humans have a limited mental capacity to deal with information. We are also limited physically, in terms of visual acuity, strength, dexterity and so on. Thus, workload reflects the degree to which the demands of the work to be undertaken affects our mental and physical capacities.