Lets try the same example but with a 9-hour duration maximum. Is it possible to fit 3 shifts of 9 hours instead of 4? This would reduce the number of part-time employees that we would need. Right? And we should have enough hours since three 9-hour shifts makes 27 hours available and we have 26 hours of work.
The table below shows that result. We pencil in 9 hour from the beginning of the day (shift 1) and 9 hours from the end of the day (shift 2). Notice that shift 3 starting at 9a covers the rise and fall of workload at the beginning and end of the day very nicely. But there is a catch. Notice the effect on the coverage. Although there is enough hours for the whole day, they are not distributed according to the actual workload. Coverage shows that there is one employee extra for 3 hours in the afternoon and that there is one missing employee during the peak time of 3p to 5p.
This is just to show that peaks and valleys have a significant influence on how the shifts are carved in a day.
| 26.0 / 26.0 | Total |
6a |
7a |
8a |
9a |
10a |
11a |
12p |
1p |
2p |
3p |
4p |
5p |
6p |
| Workload |
26 |
1 |
1 |
1 |
2 |
3 |
3 |
2 |
2 |
2 |
3 |
3 |
2 |
1 |
| Coverage |
27 |
1 |
1 |
1 |
2 |
3 |
3 |
3 |
3 |
3 |
2 |
2 |
2 |
1 |
| Shift 1 |
9 |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
|
|
|
|
| Shift 2 |
9 |
|
|
|
1 |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
|
| Shift 3 |
9 |
|
|
|
|
1 |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
| Shift 4 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Shift 5 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
The example above was simple. Real workload can produce easily up to 25 shifts per day. It becomes quite difficult to determine the best start and end times when these situations occur. Here are a few simple rules to help carve the shifts when workload is big:
- Determine the night shifts first. Usually, night is when workload is at its lowest and night shifts are the ones most employees dislike. They are known to disrupt sleep patterns and cause fatigue.
- Work around the peaks. Identify the highest demand in work and pencil in your shifts going both left (for a shift ending after the peak) and right (for a shift starting before the peak). You can determine the final duration of each shift once you’ve established the number of shifts you have.
- Determine what is good enough for coverage. If there is a need for 20 employees and you have 19 shifts for that hour, that’s probably good enough. But on the other hand if you need 2 employees and you only have one, you probably need to cover that hour.
- Merge the shifts. After the initial carving, you can take a look at shifts that could be merged. This happens when you have a lot of shifts and you don’t necessarily look at long shifts when you are penciling them in. You can reduce the final count by merging a shift that ends at or near the start time of another shift.
Time independent workload
For time independent workload, there is no need to carve shifts based on start and end times. You simply need to decide when
Mixed workload
A mixed workload where both time dependant and independent hours need to be assigned will merge both tables together.