Fatigue plays a major role in impairing performance, safety, and productivity in the workplace. It is one of the most prevalent symptoms in the workforce, affecting 54% of individuals. Worker fatigue has substantial economic burden, estimated at $18 billion a year in injured workers or workers' compensation and reduced productivity (Caruso, 2014; Lerman et al., 2012). Despite extensive research regarding mechanisms and consequences of fatigue, it still remains a significant concern in various industries, ranging from aviation to healthcare to oil and gas operations, and public safety.
Oil and gas extraction (OGE) workers are exposed to intensive shift patterns and long work durations, coupled with intense physical and mental workload inherent of the OGE environment. From 2003–2014, 1331 OGE workers died while working, resulting in an annual fatality rate seven times higher than that for all U.S. workers (Figure 1).
In the OGE industry, fatigue is especially a critical safety risk. Operator fatigue has been implicated as a contributing factor in significant safety incidents, such as the BP Texas City refinery, which resulted in 15 deaths, 180 injuries, and significant economic losses. The Chemical Safety Board investigation (CSB, 2007) concluded that the Isomerization Unit operators were likely fatigued from working 12-hour shifts, some working as many as 29 consecutive days during the turnaround of the unit prior to startup, and that, as a result, the operators' judgment and problem-solving skills were likely degraded, hindering their ability to determine that the tower was overfilling with hydrocarbons and to take prompt corrective actions.
Fatigue, generally defined as a physiological state of reduced mental or physical performance capability resulting from sleep loss, circadian phase, and workload, has been implicated as a serious risk factor in a majority of the cases affecting worker safety. Both industry and federal agencies have determined that "decreasing fatigue-related injuries and fatalities in the OGE industry" is one of their top strategic research (to practice) priorities. However, one of the major barriers that currently impacts the development of effective fatigue mitigation practices in OGE workers is the assessment of fatigue.