Fatigue is a major human factors issue in aviation safety.Caldwell JA, Caldwell JL. Fatigue in military aviation: an overview of US military-approved pharmacological countermeasures. Aviat Space Environ Med 76(7, Suppl):C39-51, 2005. The Fatigue Avoidance Scheduling Tool (FAST) was developed by the United States Air Force in 2000–2001 to address the problem of aircrew fatigue in aircrew flight scheduling.Air Force Research Lab summary of project, http://www.dtic.mil/dticasd/ddsm/srch/ddsm0219.html FAST is a Windows program that allows scientists, planners and schedulers to quantify the effects of various work-rest schedules on human performance. It allows work and sleep data entry in graphic, symbolic (grid) and text formats. The graphic input-output display shows cognitive performance effectiveness (y axis) as a function of time (x axis). An upper green area on the graph ends at the time for normal sleep, 90% effectiveness. The goal of the planner or scheduler is to keep performance effectiveness at or above 90% by manipulating the timing and lengths of work and rest periods. A work schedule is entered as red bands on the time line. Sleep periods are entered as blue bands across the time line, below the red bands.
The calculated performance effectiveness represents composite human performance on a number of cognitive tasks, scaled from zero to 100%. The oscillating line in the graph represents expected group average performance on these tasks as determined by time of day, circadian rhythm, time spent awake, and amount of sleep, and various confidence limits around the average may be displayed. The graphic display may be cut and pasted into reports and briefing slides. Cognitive effectiveness estimates for work periods of any length may also be cut and pasted in tabular format.
History FAST was developed under Phase 1 and 2 Small Business Innovation Research (SBIR) contract awards from the US Air Force Research Laboratory (AFRL), Human Effectiveness Directorate, to NTI, Inc.NTI, Inc. (Dr. Douglas R. Eddy, Principal Investigator) with Science Applications International Corporation as a subcontractor (Dr. Steven R. Hursh, Modeler).Eddy DR, Hursh SR. Fatigue Avoidance Scheduling Tool (FAST). Technical Report No. AFRL-HE-BR-TR-2001-0140, Brooks AFB, TX, 2001.Eddy DR, Hursh SR. Fatigue Avoidance Scheduling Tool (FAST) Phase II SBIR Final Report, Part 1. Technical Report AFRL-HE-BR-TR-2006-0015, Brooks City-Base, TX, 2006a.Eddy DR, Hursh SR. Fatigue Avoidance Scheduling Tool (FAST) Phase II SBIR Final Report, Part 2. Technical Report AFRL-HE-BR-TR-2006-0040, Brooks City-Base, TX, 2006b.Hursh SR, Redmond DP, Johnson ML, Thorne DR, Belenky G, Balkin TJ, Storm WF, Miller JC, Eddy DR. Fatigue models for applied research in warfighting. Aviat Space Environ Med 75(3, Suppl.): A44–53, 2004. Fatigue predictions in FAST are derived from the Sleep, Activity, Fatigue, and Task Effectiveness (SAFTE) simulation invented by Dr. Hursh, currently the President of the Institutes for Behavior Resources and Adjunct Professor of Behavioral Biology, Johns Hopkins University School of Medicine.
The SAFTE simulation integrates quantitative information about (1) the circadian rhythm in metabolic rate; (2) cognitive performance recovery rates associated with sleep, and cognitive performance decay rates associated with wakefulness; and (3) cognitive performance effects associated with sleep inertia to produce a 3-process model of human cognitive effectiveness. The SAFTE model has been under development by Dr. Hursh for more than a decade. In the general architecture of the SAFTE model, a circadian process influences both cognitive effectiveness and sleep regulation. Sleep regulation is dependent upon hours of sleep, hours of wakefulness, current sleep debt, the circadian process and sleep fragmentation (awakenings during a sleep period). Cognitive effectiveness is dependent upon the current balance of the sleep regulation process, the circadian process, and sleep inertia.
The SAFTE simulation has received a broad scientific review and the DoD considers it a complete, accurate, and operationally practical model to aid operator scheduling.DoD's SAFTE Model, Hursh, et al., The SAFTE simulation's software implementationChaiken SR. A Verification and Analysis of the USAF/DOD Fatigue Model and Fatigue Management. Technical Report AFRL-HE-BR-TR-2005-0162). Brooks City-Base, TX, 2005. and applicabilities have since been validated in aviation and railroadHursh SR, Raslear TG, Kaye AS, Fanzone JF. Validation and Calibration of a Fatigue Assessment Tool for Railroad Work Schedules, Summary Report. Technical report DOT/FRA/ORD-06/21, U.S. Department of Transportation, Federal Railroad Administration, Office of Research and Development, 2006 work environments.
During the Phase 2 effort, the model was refined with findings from AF research and other studies providing a blood alcohol index, lapse index, sleep timing algorithm, and interface features (performance variation percentiles, mission timeline, grid input,Miller JC. Usability Improvement for Data Input into the Fatigue Avoidance Scheduling Tool (FAST). Technical Report AFRL-HE-BR-TR-2005-0072, Air Force Research Laboratory, Brooks City-Base TX, 2005. (ADA435739) and fatigue factors dashboard, to name a few). FAST provided the military physiologist the first computerized tool that used a homeostatic model for optimizing aviator performance under conditions of limited sleep while minimizing the need for pharmacological aids. Missions could be planned that provided sufficient rest to maintain effective performance and, when normal, nocturnal sleep was impossible, arrange interventions such as naps or pharmacological treatments to maintain performance. The tool was intended to improve flight safety, optimize mission success during sustained operations, and minimize the need for pharmacological aids.
During the Phase 2 and Phase 3 efforts, the FAST team had the opportunity to train different groups of AF personnel on the use of FAST to solve fatigue problems they were having with sustained operations, overseas deployment, and night training operations. The training was accomplished with numerous groups in part through several of the USAF School of Aerospace Medicine's (USAFSAM) educational functions (2002–2007) and in part through the AFRL Aviation Fatigue Countermeasures Workshop taught approximately tri-annually by Drs. John A. Caldwell, J. Lynn Caldwell, and James C. Miller. Students over the years included flight surgeons, aerospace physiologists and aerospace physiology technicians on annual training; aerospace physiologists and aerospace physiology technicians during initial training; flight surgeons participating in USAFSAM's Residency in Aerospace Medicine (RAM) and Advanced Aerospace medicine for International Medical officers (AAMIMO) programs; and aviation safety officers from The U.S. Air Force, Navy, Marines, and Army, and from the Canadian Forces. Many of these new users recommended that the FAST product be transformed in several ways to make it more useful to operational units.
FAST was used successfully by the development team, Air Force researchers, and several AF operational units to solve fatigue problems throughout AF operations. Scientists in the Warfighter Fatigue Countermeasures Branch (WFC, now AFRL/RHPF) and operators used FAST to identify and avoid fatigue in more than 2,000 hours of B-2 Spirit bomber operations from Whiteman AFBAs of summer, 2006; personal communication to Dr. Miller from the Whiteman Aerospace Physiology Section and night operations at Shaw AFB, to optimize shift work schedules for security forces at Brooks AFB, to assess the impact of sleep loss and night operations in accident investigation, and many other consults. During the period 2000–2007, Dr. Miller used FAST to assist USAF mishap investigation boards in at least nine investigations of aviation mishaps. Additionally, FAST was used to prepare guidance for various operational units in the United StatesMiller JC, Dyche J, Cardenas R, Carr W. Effects of Three Watchstanding Schedules on Submariner Physiology, Performance and Mood. Technical Report NSMRL-TR-1226, Naval Submarine Medical Research Laboratory, Groton, CT, 2003. (ADA422572)Miller JC. A Fatigue Checkcard for Mishap Investigations. Technical Report AFRL-HE-BR-TR-2005-0071, Air Force Research Laboratory, Brooks City-Base TX, 2005.Miller JC. Operational Risk Management of Fatigue Effects. Technical Report AFRL-HE-BR-TR-2005-0073, Air Force Research Laboratory, Brooks City-Base TX, 2005. (ADA434836)Miller JC. Scheduling Aircrews 1: Intra-Theater 24/7 Operations. Technical Report AFRL-HE-BR-TR-2005-0074, Air Force Research Laboratory, Brooks City-Base TX, 2005. (ADA434696)Miller JC. Scheduling Aircrews 2: Nighttime Missions. Technical Report AFRL-HE-BR-TR-2005-0075, Air Force Research Laboratory, Brooks City-Base TX, 2005. (ADA435393)Miller JC. Scheduling Aircrews 3: Deployment. Technical Report AFRL-HE-BR-TR-2005-0047, Air Force Research Laboratory, Brooks City-Base TX, 2005.Miller JC. Fundamentals of Shiftwork Scheduling. Technical Report AFRL-HE-BR-TR-2006-0011. Air Force Research Laboratory, Brooks City-Base, TX, 2006. (ADA446688) and Canada.Paul MA, Miller JC. Fatigue Assessment in Camp Mirage CC130 Aircrew: Recommendations for Pharmacologic Intervention. Technical Report 2004-021, Defence R&D Canada – Toronto, 2004.Paul MA, Miller JC. Consideration of 5 Canadian Forces Fire Fighter Shift Schedules. Technical Report 2005-227, Defence R&D Canada – Toronto, 2005.Paul MA, Gray GW, Miller JC. Preliminary Assessment of Zopiclone (Imovane) Use in Camp Mirage Aircrew. Technical Report 2006-077, Defence R&D Canada – Toronto, 2006. (ADA472982)Paul MA, Gray GW, Miller JC. Cognitive effectiveness of CF-18 instructor pilots during routine training. Technical Report 2007-028, Defence R&D Canada – Toronto, 2007. (ADA472954)Paul MA, Gray GW, Miller JC. Fighter Pilot Cognitive Effectiveness during Exercise Wolf Safari. Technical Report 2007-020, Defence R&D Canada – Toronto, 2007. (ADA472968)Paul MA, Gray GW, Nesthus TE, Miller JC. An Assessment of the CF Submarine Watch Schedule Variants for Impact on Modeled Crew Performance. Technical Report 2008-007, Defence R&D Canada – Toronto, March, 2008. These FAST users had no problems entering data, trying different schedules, making modifications to existing schedules, or interpreting results. However, all of these applications involved experts or personnel that they had trained. Attempts to apply FAST to daily flying scheduling operations were unsuccessful because the user interface was designed originally for scientists, not for operators.