Chapter 15 - Work Schedule Design

Learning Outcomes

After reading through this chapter, you should be able to:

  • Discuss respective responsibilities of employee and employer in the context of a fatigue risk management system.
  • List considerations when designing working time arrangements.
  • Explain the pros and cons of different types of shifts.

Shiftwork on the rise

It is estimated that fatigue is responsible for at least as many crashes on the road as alcohol. Despite this, fatigue has only recently begun to receive attention from regulatory bodies. As the workforce increasingly moves towards shift work and alternative working arrangements, the potential for fatigue-related risks increases. This problem is further compounded by the growing use of highpowered machinery where the margin for error is small and the potential for serious injury is high.

Globalization and competition are forcing organizations to adopt new flexible working time arrangements that include 24-hour operations.

There is little doubt that flexible working time arrangements have productivity benefits. Flexible, non-standard working hours are also attractive to employees whose home responsibilities and personal commitments prevent them from working traditional schedules.


Work schedule design as a countermeasure to fatigue

The best-known countermeasure to fatigue is sleep. Sleep opportunity is determined to a great extent by the hours you are not at work. Therefore, fatigue reduction strategies must include work schedule design. It is important to remember that there is no perfect working time arrangement that suits everyone all the time.

When designing working time arrangements, the following should be considered:

  • length of shifts
  • number of consecutive shifts
  • direction of rotation in alternating shifts (forward or backward)
  • type of shifts to be worked (nights, afternoons and mornings, days)
  • staffing levels, experience, expertise, and opportunities for job rotation
  • breaks between and within work periods
  • types of tasks being undertaken, (repetitive, boring, exciting, stimulating)
  • consulting with all stakeholders about developing new work schedules – participation by all is likely to foster feelings of ownership of the outcome
  • testing changes to the work schedule to determine impacts on the health, safety, and productivity of employees and the company.

Employer and employee responsibilities

Managing fatigue and associated risks are the dual responsibility of employers and employees. As will be seen in the next two sections, various types of shifts have various effects on workers and their lives, and entail some fatigue-related risks. Both employers and employees must be aware of the risks involved with various types of shifts. Examples of the respective responsibilities of employers and employees with regard to fatigue are listed below.

Employer responsibilities

  • Appropriate and safe work schedule design that allows for adequate recovery periods during the shift and between shifts.
  • Ensuring safe work practices, such as scheduling sensible levels of overtime.
  • Appropriate and safe shift duration.
  • Assessment, control, and monitoring of fatigue related hazards.
  • Development of policies, procedures, and practices to manage risk related to fatigue. For example, where napping is allowed, there should be clear instructions on how to deal with sleep inertia.
  • Providing information on workplace hazards, such as fatigue.

Employee responsibilities

  • Arriving at work in a fit state to work the expected shift length.
  • Reporting all incidents and accidents.
  • Maintaining communication with work colleagues, management, and relevant unions.
  • Being aware of fatigue and how to counter it in the workplace; for example, by getting adequate rest or sleep prior to work times.

Different types of shifts

There are a number of different types of non-traditional shifts that are worked in industry. Extended shifts are but one alternative to the regular 9-to-5 workday. Workers can also find themselves assigned to shifts starting early morning, in the afternoon, or at night. Work teams can be assigned to these shifts according to slow or fast rotations. There are no hard-and-fast rules about which shift schedule is best. However, as discussed below, some are more attractive than others in terms of the physiological, psychological, and social impact they have upon workers.

Extended shifts

Extended shifts involve either starting a shift earlier or finishing later than the standard 9-to-5 work day. There are many reasons an organization may choose to use extended shifts. In some cases, extended shifts allow for longer hours of production, without the need for night work. Extended shifts are also popular among employees because of the extra money they can earn working longer hours.

Alternatively, the standard 37.5 hour work week can be compressed into three or four days, allowing bigger blocks of time off between shift sequences.

Working the occasional extended shift is unlikely to significantly affect fatiguerelated risk. This is especially so if the shift does not affect sleep opportunity (i.e., starting before sunrise, or finishing after “normal” bedtimes). Over longer periods, shifts longer than 10 or 12 hours should be avoided. Even if these shifts do not specifically affect your sleep periods, they will reduce the amount of social time available. Research has shown that employees often sacrifice sleep in exchange for a healthy social life if they do not have sufficient time for both, producing higher fatigue levels. If longer shifts are required, make sure you have adequate recovery time after your shift has ended.

Night shifts

Humans are diurnal, which means we are naturally active during the day and sleep at night. Because of this, it is particularly difficult to completely adjust to night shifts. Night work requires you to be awake when your natural tendency is to be asleep, which disrupts body rhythms and affects the quality and quantity of sleep. Night workers generally get less sleep, and the sleep they do get is of poorer quality than that of day workers.

Unlike most other animals, we are influenced and motivated by what we choose to do and how we choose to do it. Motivation plays a role in how you manage your work hours. Money has generally been used to compensate employees who work at non-traditional times. Those who work at night, in the evening, and on weekends are traditionally paid at a higher rate than those who work days, Monday to Friday.

Morning shifts and afternoon shifts

Although they may be less problematic than night shifts, morning and afternoon shifts are not without problems. Morning shifts that start before 7 a.m. force workers to cut sleep periods short, which can cause higher levels of fatigue at work. This has been supported by studies that show a higher frequency of accidents at the start of early morning shifts. As with the night shift, the risk of a fatigue-related incident if sleep is cut short over multiple days becomes a significant safety risk.

From a sleep perspective, afternoon shifts are ideal. Workers get home around 11 or 12 p.m., after which very few people would struggle to get 7 to 9 hours sleep. While for many people sleep is easiest after an afternoon shift it is not ideal from a social perspective. The evening meal with family or friends is valued by most as the most important period of social time. This is particularly the case for workers with young children at home. As discussed above, when individuals are deprived of social time by extended shifts, they will often sacrifice sleep to catch up on lost social time on other days. Again, this can cause a vicious cycle with fatiguerelated risk.

Shift rotation

Where night work is required, rotating shifts are often employed to share the night shifts among employees, rather than restricting them to one group of employees. Employees working nights typically get less sleep, which can accumulate to cause high fatigue levels particularly over multiple days in a row. Using a rotating shift schedule can reduce fatigue-related risk by giving employees fewer night shifts in a row.

Research has found that rapid rotation of shifts (i.e., changing every few days) is preferable to a slow rotation. Similarly, rotating shifts forward (i.e., morning, afternoon, night) is preferable to rotating backward (i.e., night, afternoon, morning).


Have you noticed any differences between your sleep patterns when you’re on night shift and when you’re on other shifts?


Do you have any suggestions about how current working hour arrangements could be improved? If yes, what are they?



checkmark Knowledge Check

  • Name three factors you should consider when designing work schedules.
  • Name two employee responsibilities and two employer responsibilities with respect to managing fatigue-related risks.
  • Name one negative aspect for each of the following shifts: morning, afternoon, and night.
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