Fatigue can be caused by many factors, including physical and mental exertion and lack of proper sleep. Fatigue issues can also be called “Alertness” issues because alertness includes a broader range of factors associated with human fitness for duty.

Most aviation maintenance personnel, who have worked extended hours to repair an aircraft away from base, remember that they were fatigued more than they remember the complexity of the technical repair. The entire workforce is susceptible to errors induced by fatigue. FAA research found that the maintenance workforce does not achieve proper sleep. Further, the workforce does not recognize their fatigue and compensate accordingly.

Fatigue/Alertness Management programs are generally voluntary. Nevertheless, Fatigue/Alertness Management is an important component of a Human Factors program.