Fatigue on a 12-Hour Rotating Shift
A meat processing plant employs 240 workers on 12-hour rotating shifts: two day shifts, two night shifts, then four days off. In the last three months, there have been six forklift near-misses, three hand injuries, and one lost-time back injury. A staff survey found 38% sleep less than six hours before a shift, and 44% report driving home 'drowsy'. The plant has a fatigue policy requiring a 10-hour break between shifts, but overtime is common because 18 positions are vacant. Workers are offered free coffee and a $1.50 vending machine subsidy; there is no quiet room. The union wants the night shift shortened to eight hours; management says this would cut production by 9% and threaten 30 jobs. WorkSafe has asked for a fatigue risk management plan.
1. Analyse the factors contributing to fatigue using a socio-ecological model and explain why an individual-focused response is insufficient.
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Individual. Sleep duration, untreated sleep apnoea, medication, alcohol, second jobs and commuting distance affect fatigue. 38% sleeping less than six hours is a signal, but it is not simply a lifestyle choice.
Interpersonal. Family responsibilities, caregiving, and shared transport shape sleep. A worker may accept overtime because their household depends on it; a partner may also work shifts, making daytime sleep difficult.
Organisational. The 12-hour rotating roster, 18 vacancies, overtime, free coffee and a $1.50 vending subsidy, and no quiet room are organisational factors. A 10-hour break policy is ineffective if overtime makes it impossible. Six forklift near-misses and three hand injuries suggest control failures, not just individual errors. Supervision, task rotation and production targets also matter.
Community and societal. Rural transport, housing quality, labour shortages and immigration settings shape who is available to work and how much overtime is required. Economic pressure can make workers reluctant to report fatigue.
Why individual focus is insufficient. Education alone tells workers to sleep better but does not give them a roster that permits it. It blames the worker and can increase under-reporting. Under the Health and Safety at Work Act, the employer must eliminate or minimise fatigue risks so far as reasonably practicable, not just advise workers.
2. Evaluate two interventions - shortening night shifts to eight hours versus a fatigue education programme - and recommend a risk-based approach.
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Shortening night shifts to eight hours. The evidence favours shorter night shifts and fewer consecutive nights for reducing fatigue-related errors, especially in safety-critical work. A 9% production cut and 30 jobs are serious consequences, but they must be weighed against injury, near-misses and legal duties. The union proposal should be tested on one line or one crew for 12 weeks, with measures of output, overtime, near-misses, injuries, sleep and sickness. If output falls less than predicted after reorganising breaks and staffing, the change may be affordable.
Fatigue education. Low cost and easy to implement, but weak on its own. It can support a risk management plan by teaching workers to recognise fatigue and report it, but it cannot fix a roster that prevents sleep. It should not be used as a substitute for schedule change.
Recommended risk-based approach. First, reduce consecutive night shifts and cap overtime; audit the 10-hour break rule. Second, provide a quiet room and scheduled rest breaks, and remove incentives that encourage caffeine over sleep. Third, manage commute risk: offer transport or a rest period before driving home. Fourth, train supervisors to act on fatigue reports. Fifth, monitor near-misses, injuries, sleep and production by crew. Education becomes one component, not the intervention. This balances jobs and safety and meets the duty to minimise risk so far as reasonably practicable.