Though shift pattern design is not easy knowing the basics does help. For example, people may call them by different names but there are only four shift configurations:
1. Meeting – a shift that finishes at the start of another shift.
2. Overlap – shift times that overlaps another shift start or end time.
3. Before and After – a shift that finishes, gaps and then another shift starts.
4. During – a shift that is completed within the time period of another shift.
However with these four shift types you can create complex patterns of shift working. In the context of 24 hour working another level of description has been added in this diagram: core, intermediate and flexible to describe the role of the shift in relation to each other.
The relationship of the four shift pattern types in a 24 hour context.
Constrained by a 24 hour period “meeting” shifts typically have an 8 or 12 hour duration. That’s easy. So are twelve 2 hour shifts but more difficult to source staff who will work them. In the military six 4 hour shifts (or watches) are not uncommon. If you dispense with the notion of the 24 hour day you can have meeting shifts of any duration e.g. submarine crews under the polar ice cap for 3 months or remote exploration teams. Now life is quickly becoming interesting. Welcome to the world of shift pattern design and the first basic principle: Always have a clear idea about what kind of “Staff Supply” you want your shift pattern to generate.