Capacity to Do It Capacity means having the time as well as the mental, physical, and emotional capacity to do a job well. Sometimes, a position might require a commitment of 55 hours a week where the person is only willing to commit 40. Sometimes the job requires a certain level of intellect, skill, knowledge, and emotional intelligence, and the person doesn’t have that capacity. This is the Peter Principle at its finest, where people are elevated to a level of incompetence.