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Fatigue risk assessment

A fatigue risk assessment identifies where tiredness, sleep disruption, or demanding work patterns could cause harm — and evaluates whether existing controls reduce that risk to a proportionate level.

It complements general workplace risk assessment. In the UK, employers must assess health and safety risks — including fatigue where it is foreseeable — and put proportionate controls in place. A fatigue assessment should be specific to roles, locations, and rosters, not copied generically from another site.

When to carry out a fatigue risk assessment

Section titled “When to carry out a fatigue risk assessment”

Consider a dedicated fatigue assessment when:

  • Introducing or changing shift patterns, including night or rotating work
  • Extending hours, increasing overtime, or adding on-call duties
  • Responding to fatigue-related incidents, near-misses, or credible reports
  • Changing roles, work locations, workload, or staffing levels
  • Onboarding a new contract, client, or operational area
  • Reviewing controls after reorganisation, acquisition, or major disruption

HSE states that changes to working hours should be risk assessed, using principles from its shift work guidance. Assessment may include tools such as a fatigue risk index, but tools support — they do not replace — competent judgement.

What to consider: fatigue risk factors

Section titled “What to consider: fatigue risk factors”

The table below lists common factors to examine. Not every factor applies to every role; scope the assessment to your operation.

Factor Examples of what to explore
Shift timing Night work, early starts (e.g. before 06:00), late finishes, split shifts
Shift duration Standard length, planned extensions, disruption-driven overruns
Rest between duties Gap between end of one shift and start of the next (“quick returns”)
Consecutive working days Blocks of shifts without adequate recovery days
Rotation speed and direction Rapid rotation between day and night; backward vs forward rotation
Breaks within shifts Frequency, length, and whether breaks are restorative
Workload and task demand Vigilance tasks, monotony, safety-critical decisions, physical demand
Travel and commuting Long journeys before or after duty; total door-to-door burden — see duty, travel, and commute
On-call and unpredictability Call-ins that disrupt planned sleep
Environment Heat, noise, isolation, lighting (especially on night shifts)
Individual and organisational factors Reporting culture, leave access, secondary employment

HSE identifies shift schedule design features — workload, activity, timing, duration, rotation direction, and breaks — as key risk factors in shift work assessment.

A practical assessment process

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Use this structure as a guide. Adapt depth to the risk level.

1. Scope

Section titled “1. Scope”

Define roles, sites, contracts, and shift systems covered. State what is excluded and why.

2. Hazard identification

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Document how work patterns and conditions could cause fatigue-related harm to workers, colleagues, passengers, the public, or contractors.

3. Who may be affected

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Include direct workers and others who could be harmed by fatigue-related error — not only the tired individual.

4. Existing controls

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Record roster rules, rest policies, supervision, reporting routes, facilities, and any quantitative methods in use (e.g. FRI).

5. Evaluation of risk

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Consider likelihood and severity of harm if controls fail. Use operational evidence: overtime logs, swap rates, incident data, and worker feedback.

6. Further actions

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Assign proportionate improvements with owners and dates. Actions might include roster redesign, minimum rest rules, training, or improved reporting — not only “awareness.”

7. Review

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Set a review date and triggers for earlier review (e.g. new contract, pattern change, significant event).

Worked example scenarios (illustrative)

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These examples show the type of reasoning an assessment should capture. They are not prescriptive rules.

Quick returns after night shifts
A warehouse depot schedules night shifts ending at 06:00 with day shifts starting at 14:00 the same calendar day. The assessment should examine sleep opportunity, cumulative load across the week, and whether rest meets policy — not only whether total weekly hours comply with working time rules.

Disruption-driven extensions
Rail maintenance teams plan 10-hour possessions but regularly overrun. The assessment should address actual hours and recovery, not planned rosters alone.

Long commutes to remote sites
Construction crews travel two hours each way to site. The assessment should consider total time burden and recovery, alongside duty length on site.

Competent person review

Section titled “Competent person review”

Assessments should be prepared and reviewed by people with relevant knowledge of:

  • The operation and roster constraints
  • Fatigue science at a practical level
  • Applicable legal, contractual, and industry requirements for your context

Software, spreadsheets, and templates can help document the assessment. They do not equal a completed assessment. A blank or partially filled template has no value until populated with site-specific evidence and signed off by someone competent.

Relationship to fatigue risk indices and FRMS

Section titled “Relationship to fatigue risk indices and FRMS”

What this page does not cover

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This page explains assessment approach. It is not legal advice, does not list sector-specific mandatory limits, and does not confirm that any particular roster is safe or compliant for your organisation.

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References

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