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Fatigue and Rosters


According to Safe Work Australia, fatigue is more than feeling tired and drowsy. In a work context, fatigue is a state of mental and/or physical exhaustion that reduces a person’s ability to perform work safely and effectively. It usually results in reduced performance such as loss of attentiveness, slower reaction times, impaired judgment, and poorer performance.

Causes of fatigue

Fatigue can be caused by work related or non-work factors or a combination of both.

  •   Prolonged or intense mental or physical activity
  •   Disruption of the internal body clock rhythms (cycles of activity and sleep)
  •   Inadequate rest breaks
  •   Sleep loss – long periods awake, or inadequate amount or quality of sleep over an extended period

Sleep loss

Sleep is a vital need like hunger and thirst and if sleep is disrupted or we are deprived of normal sleep, fatigue can result.

Most people need 8 hours sleep, although this varies among individuals. Failure to get normal sleep results in sleep debt that accumulates and can only be paid back by undisturbed, restorative sleep.

Sleep loss can occur because of events outside of the boarding role, such as a second job, family demands, street noise or pain, long commuting times etc, or events within the role, such as poor rostering, unexpected events (a student ill during the night) and extended shifts (when a rostered supervisor is not available to take over at the end of a shift).

Sleep loss can degrade every aspect of human performance. Sleep loss and sleepiness can decrease physical and mental performance and can increase negative mood and decrease positive mood. The boarding context can be a very intense, complex environment with unexpected things happening as you care for other people’s children. Supervisors need to be at the top of their game, able to react effectively and positively. They can’t do this if they are fatigued.

WHS legislation and fatigue

Fatigue as a workplace health and safety issue is a hazard that an employer has a duty to manage. Fatigue is not subject to specific requirements under current WHS legislation in the same way as noise or chemicals hazards.

Under WHS legislation, the employer has a general duty to make the workplace as safe and healthy as is practicable. Effective rostering that minimises fatigue would be an important way of meeting this duty of care.

Workers also have a duty to take reasonable care for their own safety and health and that their acts or omissions don’t adversely affect the health or safety of others. Workers must comply with any reasonable instruction and cooperate with any reasonable policy or procedure relating to fatigue at the workplace, for example fitness for work policies and policies regarding second jobs.

Rostering to reduce fatigue

  •   Minimise shifts of more than 10 hours
  •   Ensure breaks between shifts enable a minimum 6 hours continuous sleep
  •   Ensure extended shifts are compensated with longer breaks between shifts
  •   Use forward shift rotation
  •   Avoid rapid shift changes
  •   Allow at least one day free in every 7 when opportunity for unrestricted sleep is possible
  •   Minimise consecutive night shifts
  •   Allow longer breaks between and following night shifts
  •   Build in contingencies for sickness and absences
  •   Maximise the opportunity to take short breaks within shifts

Minimise shifts of more than 10 hours, and ensure extended shifts are compensated with longer breaks between shifts.

Fatigue increases on long shifts, and long shifts eat into the time available for sleep. Ensure breaks between shifts enable a minimum of 6 hours continuous sleep. Most people need 7-8 hours of sleep every day but the time that sleep is taken will influence the amount of time needed to get minimum sleep. It is more difficult to get good sleep during the day. To get the absolute minimum of 6 hours, a break of 7 hours would be required, ideally at night.

Allow at least one day free in every 7 in which opportunity for unrestricted sleep is possible.

The opportunity to get undisturbed night sleep allows sleep debt to be reduced. Two consecutive night sleeps is considered adequate to minimise sleep debt.

Speed and direction of rotation
Adapting to rotating shifts can be affected by the speed of rotation and the direction of rotation. Speed of rotation means the number of consecutive day, evening, or night shifts before a shift change occurs.

Avoid rapid shift changes, as they may further disrupt the body clock and not allow an opportunity to recover from any built-up sleep debt.

The direction of rotation means the order of shift change: A forward rotation is in the clockwise direction, from day to evening to night shift. A backward rotation is in the counter-clockwise direction, from day to night to evening shift. It is generally considered that it is easier to go to bed later and wake up later than to have to go to sleep earlier and wake earlier, as required in a backward rotation. Our body rhythms make us feel more awake and alert in the early evening. This makes it harder to fall asleep earlier. Backward rotations work against the body rhythm by forcing the supervisor to go to sleep earlier and earlier.

Minimise consecutive night shifts, and allow longer breaks between and following night shifts

Night work contributes to sleep debt and disrupts the body clock. The question of which is better, rapidly rotating night shifts, or slowly rotating night shifts is debatable. It is agreed that 4 to 7 consecutive night shifts is the worst of all worlds in getting circadian rhythms out of synch.

Longer rotations (for example, three to four weeks of working the same hours) are supposed to allow supervisors more time to get used to night shifts. However, supervisors usually return to a day schedule on their days off.

A fast rotation (every two days, for example) allows no time to get used to night work. Some researchers prefer the fast rotation because the supervisor quickly gets through the tough shifts and then has a couple of days off.

Build in contingencies for sickness and absences.

Any schedule is likely to be disrupted for one reason or another and building in contingencies helps to reduce high fatigue situations.

Maximise the opportunity to take short breaks within shifts
Whilst short breaks are never a substitute for sleep, they can provide temporary relief.

Permanent versus Rotating Schedules

We might think that permanent night (or late evening shift) supervisors adapt or get used to their work times. Usually, the longer somebody does something, the easier it becomes. With experience, many night supervisors figure out tricks or personal methods to fight off some of the night fatigue. However, research indicates that most permanent night supervisors never really get used to the schedule. That is, there are many nights when they still feel tired and sleepy. Fatigue occurs because most night supervisors go back to a day schedule on their days off. This is not surprising because family and friends are active during the day.

Also, many errands and jobs (like getting the car fixed) must be done during the day. Because most night supervisors often return to a day schedule, they never completely allow their sleep and body rhythms to adapt to being awake at night. They also sleep less during the day, so they don’t recover from fatigue. This fatigue can carry over from day to day. Over several days, fatigue can accumulate to unsafe levels.

People working rotating schedules face a similar situation. Because the shift times are always changing, they can never completely adapt to a set work schedule. Rotating schedules are often used because they are considered fairer to all supervisors. Everybody in the workforce takes their turn at both the popular and unpopular shifts. Rotating shift supervisors are always trying to get used to changing work times. This is not easy, which is why rotating shift supervisors have more complaints than other supervisors about physical health and psychological stress.

Operational requirements

Preparation of rosters need to meet operational requirements such as:

  • Expected peak load times
  • Ratio of supervisors to students at different load times (to always ensure an acceptable standard of care at all times)
  • Matching of supervisor skills and strengths
  • Sufficient overlap between shifts to allow handover
  • Leave and absences
  • Cost

Staff involvement in roster design

Roster design must take into account a number of factors including operational requirements, supervisor availability and leave scheduling. These factors make rostering a complex task in many organisations. If fatigue is to be minimised by good scheduling practices, the input of staff will be required. The reasons for seeking staff involvement include:

Obligation under WHS legislation to consult with staff: employers have a duty to consult with employees on matters that may affect their health and safety. Staff also have obligations under the same legislation to work safely.

There is no “perfect” roster: the complexity of some rostering tasks has led to the development of roster experts and expert software packages designed to produce the “optimum” solution. Software packages can be useful, but they can be based on assumptions that are at odds with both fatigue principles and supervisor perceptions and

preferences. Experience in a range of industries suggests that staff involvement in the rostering process is more likely to lead to better outcomes as staff are able to highlight factors that may be important to them (e.g. family commitments) and the roster is more broadly accepted and maintained. The Head of Boarding should set the operating parameters and allow some involvement to maximise employee preferences within these constraints.

Individual characteristics can influence suitability of a roster: the fundamental causes of fatigue such as lack of sleep and sleep cycle adjustment can be accounted for in roster design but there is still individual variation that should be considered. The amount and structure of sleep changes as we get older. We get less deep sleep and less overall night sleep particularly from the 45-50 age point onwards.

Other individual factors relate to the concept of morning people (“larks”) and night people (“owls”) and although the research doesn’t strongly support this concept, supervisors’ own perception of their best times is very important.

Personal, social or family considerations: Giving consideration to out of work factors may make rostering more complex but failure to do so can create issues through absences and requests for change. Supervisors with family responsibilities may not be obtaining sufficient rest on some shifts as they need to care for children or because they are caring

for an aged person in the household. Care also needs to be taken that one’s personal considerations, such as income, second job and lifestyle preferences do not create fatigue

risks. Rosters with several consecutive days off should be seen by supervisors as an opportunity to rest rather than as an opportunity to work more hours in another job.

Surveys of staff regarding their rosters can assist in establishing individual needs such as study or family commitments, and then discussing ways to consider these in the best way within the rostering needs of the Residence.


Steve & Jenny Florisson

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