How to measure schedule efficiency
Coverage says whether the roster is big enough; fit says whether it is in the right place. How to calculate both from a requirement and a roster, with an example.
Published
A roster can have exactly the right number of agent-hours and still fail service level every afternoon. Schedule efficiency is the measure that catches this: it compares the roster with the requirement interval by interval, not just in total. This guide defines the two measures worth tracking, works through an example, and shows what to do with the answer.
Two measures, one of them useful
Coverage is rostered agent-hours divided by required agent-hours. It answers “is the roster big enough?” and nothing else. A roster with 20 agents too many in the morning and 20 too few in the afternoon has coverage of 100 per cent.
Fit compares each interval and penalises both directions:
fit = 1 − (over-staffed hours + under-staffed hours) ÷ required hoursA roster that matches the requirement in every interval scores 100 per cent. Every misplaced agent-hour counts once as surplus in the interval it is in and once as shortfall in the interval it should have been in, so fit falls twice as fast as coverage rises.
Both are easy to calculate from two columns: agents required per interval and agents rostered per interval.
Worked example
Take the requirement curve from the FTE guide: 24 half-hour intervals from 08:00, 445 agent-hours in total, peaking at 53 scheduled agents at 11:00. Now roster it with a realistic mix of shifts: a block of early starts that runs slightly heavy in the morning, and a tail that thins out too early in the afternoon.
The comparison gives:
| Measure | Value |
|---|---|
| Required hours | 445 |
| Rostered hours | 455 |
| Coverage | 102.2% |
| Over-staffed hours | 24 |
| Under-staffed hours | 14 |
| Intervals short | 7 of 24 |
| Worst interval | 16:30, 4 short |
| Fit | 91.5% |
Coverage says the roster is two per cent generous. Fit says it is nine per cent wrong: 24 surplus hours in the morning that nobody needed and 14 short in the afternoon that customers will feel, the worst of them at 16:30 during the second peak. The roster is not too small. It is in the wrong place.
What to do with the answer
- Read the shortfall intervals first. They are the service level failures. Seven short intervals clustered between 15:30 and 19:00 point to a shift pattern that ends too early, not to a headcount problem.
- Then the surplus. Twenty-four surplus hours a day is three full shifts of paid time doing nothing. Some of it is unavoidable, because shifts are longer than peaks; some of it is training and coaching that has not been scheduled into it yet.
- Change the shape before the size. Moving two early shifts to a later start would fix most of this roster at zero cost. Adding headcount would fix the afternoon and make the morning worse.
- Track it weekly. Fit below 85 per cent that persists is a shift pattern or contract problem; fit that swings week to week is a rostering discipline problem.
Try it with your own numbers
The requirement can come from the week planner or from your WFM tool’s requirement report. The roster should count agents in a productive state, so apply shrinkage to shifts before pasting, or compare against the pre-shrinkage requirement.
1 − (over + under) ÷ required. 100% means every interval matches.
- Rostered, needed
- Rostered, surplus
- Shortfall
- Required
- Coverage
- 103.4%
- Over-staffed
- 19.0 h
- Under-staffed
- 8.5 h
- Intervals short
- 10 of 24
- Required hours
- 305.5 h
- Rostered hours
- 316.0 h
Rostered hours ÷ required hours.
Agent-hours above the requirement.
Agent-hours below it.
Worst: 12:30, 4 short.
Show the working
- 24 intervals of 30 minutes: required 305.5 agent-hours, rostered 316.0.
- Coverage = 316.0 ÷ 305.5 = 103.4%.
- Interval by interval, the roster is over by 19.0 h and under by 8.5 h.
- Fit = 1 − (19.0 + 8.5) ÷ 305.5 = 91.0%.
Rosters that fit the curve are what a scheduler is for. Pebble WFM builds the roster against the requirement and publishes it. Free month, no card needed.
Common mistakes
- Reporting only coverage. It is the number finance asks for and the one that hides the problem.
- Comparing shifts with a shrunk requirement. Bodies on shift versus agents on the phones will always look over-staffed by the shrinkage percentage.
- Averaging over a week. A week’s fit hides a Monday that fails and a Friday that is over-staffed. Look at each day.
- Confusing it with adherence. A roster can fit perfectly and still fail because nobody followed it.
Where next
- How to calculate FTE from contact volume: where the requirement curve comes from.
- When a spreadsheet stops being enough: fit below 85 per cent is the first sign.
Frequently asked questions
- What is the difference between schedule efficiency and schedule adherence?
- Efficiency measures whether the roster matches the requirement. Adherence measures whether agents follow the roster. A centre can score well on one and badly on the other, and they are fixed by different people: efficiency by the planner and the shift patterns, adherence by team leaders.
- Should the requirement include shrinkage before I compare it?
- Compare like with like. If the rostered figure counts agents scheduled to be on the phones (shifts minus breaks, coaching and so on), compare it with the requirement before shrinkage. If the rostered figure is bodies on shift, compare with the requirement after shrinkage. Mixing them makes every roster look over-staffed by the shrinkage percentage.
Stop doing this one interval at a time
Pebble WFM forecasts your demand, computes the staffing requirement for every interval, builds the roster and publishes it, with self-service for agents and a copilot that can do what a planner can. Explore a sample organisation on day one.