What is best? A 3, 4, 5, or 6-week cyclic schedule?


The classic cyclic shift model is used in all kind of sectors, such as chemical, energy, food processing … But also in the public and non-profit sectors. Each sector has its own workforce planning characteristics, from simple shift patterns to highly complex and flexible systems. The scheduling models and methods are endless.


So, how can you find your way in this jungle of possibilities? We cover that in this article about the most common basic shift models. We will also give you some examples of 3, 4, 5, and 6-week models. Keep in mind that creating a schedule is always a complicated balancing act. Financial, social, and situational aspects are important considerations. On top of that, aspects such as operating time, client preferences, work-life balance, occupancy requirements, regulations, types of labour contracts, infrastructure, availability of public transport, health effects and, of course, staffing costs to take into account. We can go on and on. Finding the best model is a serious challenge. Standard patterns are a useful starting point, of course, but a tailor-made solution is always best!


Common cyclic shift work models


The following cyclic shift models are used the most.

  • 2-week cycle – Alternation between day and night shifts, often in a series of 5.
  • 3-week cycle – Three consecutive 8-hour shifts totalling 24-hours, typically from Monday to Friday.
  • 4-week cycle – The same shifts but spread over 24 hours and 6 days a week.
  • 5-week cycle – Mostly applied where work is carried out in full continuity, 24/7.
  • 6-week cycle – A variation of the above with additional reserve (flex) shifts.


We’ll now explain more in detail what the features of 3, 4, 5, and 6-week standard shift models are.


3-weeks cycle

3-week models are usually seen in organisations that are operational during weekdays, from Monday to Friday. This model works on the same basis as a 2-week schedule – the only difference being that, besides day and evening shifts, there is also a night shift so that all 24 hours are covered. Where round-the-clock work is required, this is a good solution. The model consists of a 3-week cycle of 5 days followed by 5 evenings followed by 5 nights, interspersed by free weekends. To arrive at the same occupancy level, you can also combine a 2-week model of 5 days and 5 nights, with one week having only night shifts. Do you need staff during the weekend too? If so, you can supplement the above models with a schedule consisting only of weekend shifts comprising 2 sets of 12 hours (day and night).



These are the main characteristics of 3-shift schedules.


Working time

  • Day, evening, and night shifts.
  • The average working week is 40 hours. When official working time is less, e.g. 38 hours, workers build up credits that can be paid out in money or free time.
  • Weekend shift of 2*12 hours (24 hours), pay is usually for 40 hours.
  • Risk of ‘island formation’ during nights and weekends.
  • Training is difficult to organise for night and weekend workers.
  • Absence covered within the team (not ‘over’ teams).
  • Limited flexibility.


Social and health

  • Due to longer shift series (5), fast rotation is difficult.
  • Forward rotation is possible.
  • Workers that work from Monday to Friday are free during the weekend.
  • The free weekdays makes a “second job” possible for the weekend workers, though this may result in a lack of enough rest time and thus impact health.
  • Working only nights is only suitable for the fittest. Physical, mental, and social consequences can be significant – especially in the long run.




Cyclic 2-week model, supplemented by night and weekend shift model.


Cyclic 3-weeks model starting on Sunday, supplemented by a separate “weekends only” model



4-week cycle

In Belgium, for example, this is probably the most commonly-used model. Nevertheless, we are noticing a shift towards more frequent use of the 5-week model – the main reasons for this being health and work-life balance considerations. In short, the longer an organisation’s operating time, the more cycle weeks they require. A standard 4-week cycle can be a good solution as it results in 160 available work hours (7*24). Daily employees work day (early), afternoon (evening), and night shifts, and the fourth team is then (mostly) free. This means 4-week schedules are useful for continuous and semi-continuous work.


Characteristics 4-week cycle

Working time

  • An average working week of 42 hours.
  • Workers build ip credits that can be paid out in money or free time (e.g. 4 per week, when official weekly working time is 38 hours)
  • Little flexibility for deviations in planning, for example for extra training.
  • No additional night or weekend shift models needed. All shifts are integrated in the pattern.
  • Absences are usually covered within the teams.
  • We see that in practice, during the holiday seasons, organisations sometimes resort to a classic 4-shift system.


Social and health

  • A 4-shift roster is physically very tough.
  • However, using employees credits for extra free time, provided workers really utilise that time to rest, can alleviate this.
  • Shorter shift series (see example 3) are better than the classic model (see example 1).
  • Working no more than 4 shifts in a row creates a regular pattern of free time, resulting in more room for rest.
  • Disadvantage in the reduced number of free weekends.










Examples 4 weeks cycle


The classic 4-week model with a series of 7 shifts


A fast forward-rotating 4-week model of 7 shifts


A 4-week model with a series of four equal shifts

(*) = entry rule: the four shifts (or employees) start at different weeks. Team 1 starts in week 1, team 2 starts in week 5, team 3 starts in week 9 and team 4 starts in week 13.


5-week cycle

5-week models are used where work needs to be done 24 hours a day and 7 days a week. This model has a lot of advantages compared to the classic 4-week schedule, being less tough on employees  and offering more flexibility for employers. This is the most commonly-used schedule among companies that operate in full continuity. The average working time in a 5-shift system is 33.6 hours per week. Many schedules consist of a series of 3 to 4 shifts, followed by periods of free time. Because the official working hours total more than 33.6 hours per week, extra days must be planned – e.g. for training, meetings, peaks in workload, or support tasks. The 5-week model has several variants. Which one an organisation opts to use often depends on the sector and (collective) labour agreements. Here are some examples.


Characteristics 5-week cycle

Working times

  • Operating time of 168 hours.
  • An average working week of 33.6 hours.
  • The organisation needs to add work days to make up the official weekly working time.
  • This makes employees feel that they have fewer days off, or can choose fewer. While the latter is true, the former is not. But they get a lot in return!
  • More flexibility due to the extra available days.
  • Absences therefor can be covered across teams.
  • No additional night or weekend shift models are needed.
  • Initially, this model looks more expensive because more employees are needed. However, increased flexibility and reduced absenteeism compensate for these extra costs.


Social and health

  • 5-week models are less taxing than 4-shift schedules, provided effective working time does not exceed 38 hours.
  • This system offers the most guarantees for social time, rest time, and better sleep quality.


Read tip: 5-shift system – Belgium is behind the Netherlands?




Examples 5-week cycle

With 3-4-3 shift series





With blocks of 5 shifts


With fast forward-rotating blocks of 6 shifts

(*) = entry rule: the five shifts (or employees) start at different weeks. Team 1 starts in week 1, team 2 starts in week 3, team 3 starts in week 5, team 4 starts in week 7 and team 5 starts in week 9.


6-week cycle

In common shift models, capacity for covering absences (holidays, sickness, special leave, training, etc.) is often included in the shift itself so that replacements are automatically already available on the work floor. Another solution for a 6-week model is to use so-called reserve (back-up) shifts. These shifts are made visible as such in the schedule. Employees who work reserve shifts are designated to replace absentees. When there are no absent employees, these shifts can be used for support tasks such as administration, training, meetings, and reporting.


Characteristics 6-week cycle


Working time

  • Average working week can vary from 34.6 to 37.3 hours per week, depending on number of R or D shifts.
  • Reserve shifts represent the flexible deployment possibilities the organisation (still) has.
  • The management and control (assignment) of the reserve requires attention. Good rules are needed.
  • With reserve shifts, absences across teams can be covered.
  • No additional night or weekend shift models are needed


Social and health

  • A 6-shift schedule is less stressful than a 4-shift schedules. Everyone knows they must make time to cover colleague absences as directed.
  • There is the option of working a shorter shift series.
  • Due to reserve shifts, the timetable is less predictable than traditional shift schedules. However, this unpredictability is accounted for with reserve shifts.
  • How reserve shifts are managed determines the level of disadvantage to employees.



Examples 6-week cycle


Rest shifts for all days of the week


Only “day” reserve shifts during the weekdays


Finally: personal working hours in a shift?

When it comes to shift work, most people think of fixed 2, 3, 4, or 5-week models, not realising that individualised schedules are also possible. However, with modern techniques and tools, there is quite a bit of room for accommodating personal preferences. Implementation of these methodologies can be done gradually, in steps.


Self-scheduling is a proven method for making shift schedules more efficient, personalised, and employee-friendly, without losing control over occupancy. With self-scheduling, the employee is the focus, and they are given the space and freedom to determine when they work (within reason). For example, this method allows employees to plan care leave in advance, and makes it easier to accommodate part-time contracts, for example for parents. Older employees may also benefit from this if they are unable to work at night. Self-scheduling allows for more flexible workforce planning, reducing under and over-staffing and the need for overtime, and consequently helps improve efficiency and productivity.