The best shift work schedules involve careful planning and attention to both worker health and the needs of the company. When both the company and the workers are properly planned around, shift work becomes not only easier to do with but in some ways preferable to a traditional 9-5 system.
Shift Changes and Circadian Rhythms
It is well known that shift work tends to influence the circadian rhythms of the workers affected. When you take into account the circadian rhythms of your workers, you consider the increased difficulties of waking up and having healthy meals at irregular times. Often, you can partially compensate for evening and night shifts by either making these shifts slightly shorter than regular shifts, or by providing perks such as the ability to leave earlier based on accomplishing the worker's metrics early. While this may not always be practical, providing incentives to non-traditional shift workers can improve their morale.
Overlap
Overlapping shifts is often necessary to accommodate for easing workers into their shift, as well as for sharing pertinent shift-specific information or to work with commute delays. Even putting a 15-minute to half-hour overlap into the schedule, while seemingly cost-prohibitive, can often result in a more productive shift. When coupled with allowing workers of non-traditional shifts to leave somewhat early if their metrics are met, the additional costs of overlap can often be normalized. Overlap can also be a way to provide workers who desire overtime with an additional "partial shift" if the amount of work justifies keeping them on.
Consider Rotation
Often, rotating schedules allow workers to have days free, evenings free and nights free on a generally recurring basis. These rotating shifts can be fair because they keep the workers from burning out on a given shift and schedule. However, shift rotation should be used in moderation due to the fact that too much unpredictability can lead to poor sleep patterns, more mistakes made and lessened morale on the whole. Shift rotation and part-time staffing can often supplement a regular full time staff when continual staffing is required, but when there may not be enough hours on the payroll for every shift to have full coverage. When possible, shift rotation is also important for workers who have family commitments, as having their evenings free much of the week while having their days free on weekends can be a valuable component of work-life balance.
7 Day or Weekends
In some cases, your shift schedules are going to be 7-day per week considerations. If this is the case, rotating weekends for workers can get complicated unless you use effective software to balance the schedules. Since it is unreasonable to expect people to work every day with no time off, they will need some kind of weekend regardless of which days it ends up falling upon. Keeping up a steady and uniform weekend for your entire workforce may work better for simplicity's sake.
Enforce Fairness
It is tempting to make conscious scheduling decisions upon who will be working. While this might seem fair based upon your perception of their work ethic and their family situations, this method of scheduling is generally unfair. For this reason, the use of scheduling software that can automatically and even semi-randomly schedule when given individuals are going to work is the fairest way to balance the work load across individuals. While it is sometimes important to override the software for special considerations or because of an unusual situation, much of the time the right software enforces fairness in a way management may not be able to.