Field notes › Compliance
Fatigue management for shift workers: rostering nights, swings and back-to-backs
Fatigue management for shift workers starts with the roster. Most of the fatigue a shift worker carries is set before the first shift begins: how long each shift runs, how many run in a row, how fast day turns to night, and how much rest and travel sit in between. Safe Work Australia's guidance gives rosterers figures to design against, and the rosterer's job is to build patterns around them and catch the booking that quietly breaks them.
How shift work builds fatigue
Safe Work Australia describes fatigue as a state of physical, mental or emotional impairment that can develop over the short or long term. Its model Code of Practice on managing the risk of fatigue at work groups the causes as work hours and shift design, tasks, equipment and environment, and individual factors such as sleep, health and commuting. A rosterer controls the first group almost entirely and has a hand in the others.
The Code's main point about causes is that they combine. A long shift on its own may be manageable. The same shift at night, in the heat, at the end of a run and followed by a long drive home, is a different risk. The Code also says risk climbs with duration, frequency and severity, so a pattern worked week after week builds fatigue no single shift shows. Its example is 12 hour shifts five days a week for several months. It cites studies finding that being awake for 17 hours has a similar effect on performance to a blood alcohol content of 0.05%.
The figures a rosterer designs against
The Code sets out recommended controls for shift design. They are what a business "should" do, not legal limits, and the right figure depends on the other hazards in the work. A model Code also only has legal effect in a state or territory that has approved it, and Safe Work Australia says to check with your local WHS regulator whether that has happened. On top of that, the Code notes that mining, rail, heavy vehicle, civil aviation, offshore oil and gas and maritime work can carry their own fatigue-specific legal requirements. As at September 2026, these are the model Code's figures:
| Roster element | Model Code guidance |
|---|---|
| Rest between shifts | No less than 12 hours |
| Days worked in a row | No more than 5 |
| Days off | At least one full day a week |
| Between shift blocks | At least two consecutive nights of sleep opportunity |
| Successive night shifts | No more than 3 |
| Notice before night work | At least 24 hours |
| Time of day | Start no earlier than 6 am and finish by 10 pm, where reasonably practicable |
| Breaks at work | At least 30 minutes every 5 hours |
| High fatigue risk work | Consider shifts of no more than 8 hours and avoid overtime |
Safe Work Australia's page on managing fatigue risks repeats the core of it: allow at least 12 hours to recover between shifts, limit consecutive night shifts to 3, avoid safety critical work between 2am and 6am, and give as much notice as possible before night shifts. It also makes a point rosterers can use. Where you can't avoid long shifts, you may need to do more elsewhere, such as more breaks or more control over the pace of work.
Fatigue management for night shift workers
Night work is mostly a body clock problem. The Code says "the risk of fatigue increases after 10 pm and is particularly high between 2 am and 6 am", when the body is biologically programmed for sleep. It lists rapid changes between day and night shifts, more than three successive night shifts, travel between midnight and 6 am, and less than 24 hours' notice before night work as hazards.
For a rosterer that turns into habits. Rotate forward, from day to evening to night, since the Code recommends forward rotation and lists backward or slow rotations as a hazard. Don't flip a worker from nights straight back to days. Give real notice, because short notice takes away the chance to plan sleep before the switch. The Code also suggests encouraging a nap in the afternoon before the first night shift. And look at the last night as closely as the first, because that's the shift before the drive home. Keeping day and night crews straight on the timeline is covered in rostering day and night shifts without double-ups.
Swing rosters and back-to-back shifts
A 2/1 or 8/6 swing puts more than five days in a row on site by design, so a swing roster sits outside one of the Code's figures before anyone is booked. That means the other controls carry more weight: shift length, the number of nights in the block, rest between shifts, the camp and the travel. The Code's fly-in fly-out case study lists what one company used, including maximum work hours, minimum rest periods, recovery time between shift cycles, fewer night shifts where the work allowed, buses from the airport to site, and accommodation with blackout curtains and sound proofing. For the patterns themselves, swing rosters explained goes through 2/1, 8/6 and the ones in between.
Back-to-back shifts are on the Code's list of long hours hazards, next to double shifts and on-call work on top of regular shifts. In labour hire, back-to-back usually happens across clients rather than inside one. A worker finishes a swing for one client and starts another client's swing a couple of days later, and each client's roster looks fine on its own. The Code's labour hire example says the labour hire business "must consider the cumulative fatigue arising from all the different workplaces the worker is sent to". The roster that shows the join between those swings is the provider's.
The break at home counts too. The Code lists not having at least two consecutive nights' sleep between shift blocks as a hazard, and it says workers can be expected to cooperate with a policy on telling you about second jobs. A break filled with another booking or a second job isn't recovery time, whatever the roster calls it.
How a rosterer controls fatigue at work
None of this needs a new system to start. It needs a few rules the rostering desk follows every time.
- Write down your limits. Start from the Code's figures, add the host's fatigue plan and any industry rules, and use the stricter figure where they differ.
- Look at the worker, not the shift. Before you confirm a booking, check the fortnight either side across every client, travel days included.
- Publish early and change late rarely. The Code suggests minimising roster changes within 24 hours of a shift and planning for absences so workers aren't called in at short notice.
- Make any pattern outside your limits a second person's decision, recorded with the reason.
- Give workers a way to say they're too tired that won't cost them shifts. The Code says responses should be non-punitive where possible so reports stay accurate.
- Check actual hours against the roster. The Code suggests reviewing differences between rostered and actual hours, shift swaps and unplanned overtime.
Two more points from the Code belong on the rostering desk. A business's duty isn't reduced by a worker's willingness to work extra hours or come in when fatigued. And the people who assign shifts should be trained in how to schedule low risk shifts, with a way to escalate when there aren't enough workers to roster safely. The short-notice fill tests both. Someone pulls out at dawn, and the first person to say yes is the one who finished nights yesterday.
Where rostering software helps, and where it doesn't
The Code says scheduling software can support shift design, but it needs human interpretation and should be one of several inputs into roster design. That's a fair description of what a roster tool can do. Mustr puts every client site on one timeline with a lane per site and day and night shifts in their own sub-lanes, so a worker's shifts across all clients sit in one view. Anyone locked into another site that week is greyed out with the clashing site and dates, shifts repeat weekly for swing patterns, and the audit trail records who changed what and when. Mustr does not enforce fatigue rules. They're on the public roadmap, so today it won't stop a booking that breaks your rest limits, and that check stays with the rosterer.
Questions people ask
How do you control fatigue at work?
Start with the causes you control: shift length, rest between shifts, the number of days and nights in a row, and notice before changes. Safe Work Australia's guidance also covers tasks, the work environment, accommodation and individual factors such as long commutes. Where one hazard can't be controlled, such as a long shift that can't be shortened, it says to do more on the others, like more frequent breaks.
What is fatigue management for night shift workers?
It is rostering and work planning that respects the body clock. Safe Work Australia's model Code suggests no more than three successive night shifts, at least 24 hours' notice before night work and a forward rotation from day to night. Safe Work Australia also suggests avoiding safety critical work between 2 am and 6 am.
What are some fatigue management tips for shift workers?
Use the sleep opportunities your roster gives you, and tell your supervisor or labour hire office if you are fatigued. Safe Work Australia lists both as examples of a worker's duties, along with not driving when fatigued and following policies on second jobs. Workers must also follow reasonable instructions, such as taking regular breaks.
What are the fatigue management rules in Australia?
Under WHS laws based on the model laws, a business must eliminate or minimise the risk of fatigue so far as is reasonably practicable and consult workers about it. The detailed figures in Safe Work Australia's model Code are guidance, and the Code only has legal effect in a state or territory that has approved it. Industries such as mining, rail, heavy vehicles and aviation can have fatigue-specific legal requirements, so check with your regulator.
If you'd like to see a worker's shifts across every client site on one timeline, book a demo or try it with sample data.