Named after the company where it originated in the late 1950s, its most notable feature is seven or eight straight days off during every 28-day rotation. The DuPont generally includes maximum work stretches of four days or nights and a short 24-hour break between three day-shifts and three night-shifts.
Benefit: Most employees love having a built-in mini-vacation within every 28-day cycle.
Drawbacks: Fatigue. The 24-hour break offers little time to recuperate between two three-day work stretches.
This schedule emerged in the 1960s but rose in popularity in the 1980s. It's sometimes known as EOWEO-for "every other weekend off." Employees follow a 14-day pattern of 2-days-on, 2-days-off, 3-days-on, 2-days-off, 2-days-on and 3-days-off.
Benefit: Workers know they'll have a three-day weekend off every other weekend and won't have to work more than three night-shifts in a row.
Drawbacks: Workers don't get more than three days off in a row. Also, 2-3-2s that require workers to rotate rapidly from nights to days with each stretch of work can be fatiguing.
Four On, Four Off
Employees work four days or nights and then have four days or nights off. At some companies, workers stay on nights for as long as 24 days; at others, they switch every eight days.
Benefit: This schedule offers workers enough time off to recuperate. Also, in every eight-week cycle, workers have one period in which they get three straight weekends off.
Drawbacks: Because there are only seven days a week and the schedule has an eight-day pattern, a worker's days off move one day forward per week. Also, for every eight-week cycle, workers have five straight weekends in which they must work at least one weekend day.
While the above 12-hour schedules are the most common, companies in North America use other configurations:
- 3-days-on, 3-days-off (far more popular in Canada)
- Schedules that combine 3 or 4 days or nights on with 3 or 4 days off
- 4-days-on, 5-days-off, 5-days-on, 4-days-off, 5-days-on, 5-days-off
- Numerous variations of the DuPont.
SOURCE: ShiftWork Alert, a publication of Circadian Technologies Inc. in Cambridge, Massachusetts
Workforce, July 1997, Vol. 76, No. 7, p.36.