title: How should a bio-mathematical model be used within a fatigue risk management system to determine whether or not a working time arrangement is safe?
abstract: Bio-mathematical models that predict fatigue and/or sleepiness have proved a useful adjunct in the management of what has been typically referred to as fatigue-related risk. Codifying what constitutes appropriate use of these models will be increasingly important over the next decade. Current guidelines for determining a safe working time arrangement based on model outputs generally use a single upper threshold and are, arguably, over-simplistic. These guidelines fail to incorporate explicitly essential aspects of the risk assessment process - namely, the inherent uncertainty and variability in human sleep-wake behavior; the non-linear relationship between fatigue, task performance and safety outcomes; the consequence of a fatigue-related error and its influence on overall risk; and the impact of risk mitigation or controls in reducing the likelihood or consequence of a fatigue-related error. As industry and regulatory bodies increasingly move toward performance-based approaches to safety management, any fatigue risk management system that includes a bio-mathematical model should specify what exactly is measured by the model, and how the model can be used in the context of a safety management system approach. This will require significant dialog between the various parties with an interest in bio-mathematical models, i.e. developers, vendors, end-users, and regulators.
authors.affiliation: Appleton Institute for Behavioural Science, Central Queensland University, PO Box 42, Goodwood, SA 5034, Australia. Electronic address: drew.dawson@cqu.edu.au.
authors.forename: Drew
authors.initials: D
authors.lastname: Dawson
authors.affiliation: Appleton Institute for Behavioural Science, Central Queensland University, PO Box 42, Goodwood, SA 5034, Australia. Electronic address: david.darwent@cqu.edu.au.
authors.forename: David
authors.initials: D
authors.lastname: Darwent
authors.affiliation: Appleton Institute for Behavioural Science, Central Queensland University, PO Box 42, Goodwood, SA 5034, Australia. Electronic address: greg.roach@cqu.edu.au.
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Roach
mesh_terms: D002940:Circadian Rhythm; D005221:Fatigue; D006801:Humans; D008962:Models, Theoretical; D011336:Probability; D018570:Risk Assessment / Q000379:methods*; D017751:Safety Management / Q000379:methods*; D012890:Sleep; D012894:Sleep Stages; D013647:Task Performance and Analysis; D014940:Work Schedule Tolerance
keywords: Circadian rhythms; Fatigue model; Shiftwork; Sleep; Sleepiness; Wake