Abstract Twelve control room operators at an oil-recovery operation performed a battery of three computer-based tasks over a period of 95 days. While on day shift the operators performed the task twice, at the beginning and end of each twelve-hour shift; while on night shift the operators performed the task three times, at the beginning, middle and end of the shift. Before performing the computer-based task, each operator completed a fatigue assessment scale. During the 95 day period each operator worked two different shift schedules, each with a 28-day major cycle time. One schedule consisted of 3-days, 3-off, 7-nights, 4-off, 4-days, 7-off. The second schedule consisted of 7-days, 7-off, 7-nights, 7-off. The dependent measures consisted of latency and percent-correct factor scores from approximately 62 measures of speed and accuracy derived from an eighty-trial test battery. Results suggest that on a four day shift schedule, on the 4th day reaction time improves relative to the previous three days, and when the operators are on day shift their accuracy declines on the 3rd and 4th day, reaction time performance during seven consecutive night shifts becomes poorer on nights six and seven, and the placement of testing equipment in close proximity to the control room leads to distracted test takers.
Introduction The process control-room staff of an oil recovery operation proposed to test a new shift schedule designed to provide them with more days off in a row.
Before the study began, process control-room operators worked 12-hour shifts on a 28-day rotation which included, 3-days, 3-off, 7-nights, 4-off, 4-days, 7-off. They proposed changing the schedule to 7-days, 7-off, 7-nights, 7-off, In addition to providing the operators with more days off in a row, the new schedule would increase the number of consecutive day shifts worked to seven.
Two questions are raised by the shift schedule change. First, do operators like the new shift schedule better than the old one? And, second, is control-room operator performance worse during the 7-day rotation than during the 3- or 4-day rotations?
P. 485^