FRMS Solutions


SAFTE-FAST is the validated and widely used fatigue model used to assess fatigue for an entire workforce. In aviation, it is the same model used by the US Federal Aviation Administration suitable for assessment of pairings, planned rosters, and as-flown rosters. In rail, SAFTE-FAST is the US Federal Railroad Administration-approved model to evaluate all regulated schedules. For shiftwork, SAFTE-FAST provides a rapid way to isolate shift patterns that may cause excess fatigue in support of fatigue risk management.

SAFTE-FAST Components

SAFTE-FAST consists of two Windows programs: the Modeler and Manager.

The Modeler:

  • Reads a standard xml file of multiple schedules
  • Estimates the pattern of sleep
  • Processes the pattern of work and sleep through the SAFTE model

The Manager:

  • Processes Modeler results
  • Provides a rank ordering of all schedules according to a range of fatigue metrics
  • Helps the fatigue manager rapidly isolate "outliers" - schedules that might create excessive fatigue risk


Any schedule in the Manager can be visualized in detail in SAFTE-FAST Console. SAFTE-FAST also generates a Summary file useful for aggregate fatigue assessment, comparison of fleets or work groups, planned versus actual, and trending over time using the Reporting Tool.



SAFTE-FAST provides an integrated and science based process for analysis of fatigue risk in an entire work force or in individual cases, identifying fatigue factors that inform mitigation decisions.

SAFTE-FAST provides the most trustworthy predictions of crew performance that maximizes the benefits of fatigue risk management, improves safety, minimizes errors and incidents, improves morale and enhances productivity.