01 /
Sleep & recovery
A rest window is an opportunity, not proof of sleep. Timing, commuting and personal circumstances can change how much sleep is realistically available.
MAFRM / 02
Fatigue modelling
Time matters.
So does what came before.
MAFRM takes a continuous, explainable approach to fatigue analysis: a modelled state across duties and recovery periods, with assumptions that can be inspected.
The scientific context
More than hours
on a duty sheet.
Sleep regulation is commonly described through interacting homeostatic and circadian processes. Time awake and prior sleep affect sleep pressure, while biological timing shapes when sleep and alertness are promoted. [1]
Controlled sleep-restriction research also shows that performance deficits can accumulate over successive days. A single duty duration cannot describe all of that history. [2]
These established principles inform MAFRM’s continuous approach. Evidence specific to the model is addressed through its evaluation program.
02 /
Circadian timing
The same duty duration can occur at very different biological times. Early starts, night work and misalignment require explicit assumptions.
03 /
Accumulated wakefulness
A sign-on time does not establish a wake time. Where actual sleep is unknown, estimated waking time needs to be visible and treated with care.
04 /
Repeated exposure
Consecutive early duties and changing finish times can alter recovery opportunities across several days. History should remain part of the calculation.
05 /
Duty transitions
Moving from early duties to a later duty raises questions about sleep timing, biological adaptation and how long the person may have been awake.
06 /
Individual variation
Population estimates and individual observations answer different questions. Personalisation depends on adequate data, methodological support and dedicated evaluation.
What WOCL can tell us.
The Window of Circadian Low describes a biological period associated with reduced alertness. Its interpretation depends on sleep timing, acclimatisation and time-zone assumptions.
A model may flag overlap with a defined circadian window. Showing the definition used makes that indication easier to interpret within the wider operational picture.
Make the starting state visible.
A result depends on the history supplied and the state assumed at the beginning of that history. Making gaps visible avoids an unjustified appearance of precision.
MAFRM’s development work includes reproducible run identities and versioned configuration. Uncertainty reporting and a stable calculation-trace contract form part of the continuing roadmap.
Explain a result in operational language.
A useful explanation identifies which inputs and assumptions contributed to a result: the duty sequence, preceding recovery opportunities, transition and configuration used.
Model output should be traceable to the run that produced it, keeping the underlying calculation and its interpretation aligned.
Use the output in context.
MAFRM outputs are designed to contribute to a broader fatigue-risk assessment alongside operational context, reporting and professional judgement. They are model-based indications under stated assumptions, not clinical measurements or individual fitness-for-duty determinations.
Sleep, health, workload and environmental conditions can influence real-world fatigue beyond what roster-derived inputs alone can describe. MAFRM keeps those boundaries visible so the output can be used for the right question.
Read the evidence & validation approachHelp shape what comes next
A better question starts
with a conversation.
Developing a roster proposal, investigating an operational pattern or planning fatigue research? Let’s explore where MAFRM could contribute.