Work Schedules and Performance During Confinement

Thirteen investigations were carried out as a part of an 8-year program of research on the performance effects of various work/rest schedules during confinement to a simulated aeorspace vehicle crew compartment. A total of 139 subjects were tested using a standard battery of performance tasks. The synthetic work approach used provided a reliable, face-valid, and sensitive technique for assessing complex operator performance. It was found that a man can work 12 hours per day on a 4-hours work/4-hours rest schedule for periods of at least 30 days. For shorter periods, a man can work 16 hours per day on a 4/2 schedule but at a significant cost to his reserves for meeting emergencies such as sleep loss. Circadian periodicities are found in psycho-physiological functions paralleled by similar periodicities in performance functions, the latter being subject to modification by special motivational instructions.