Calculation Logic
For those who want to know exactly how it works – including formulas, calculation methods, and special cases.
Formulas & Calculation Examples
The primary metric for displaying resource utilization: Utilization % = (Total Demand / Total Available Capacity) * 100
Detailed Formula Breakdown
-
Total Demand = Planned Work + Vacancy Bookings + Absences
- Planned Work: Applies only to regular employees and not to temporary staff:
- All project assignment bookings
- All service assignment bookings
- Info bookings when assignment level > 0%
- Vacancy Bookings:
- Bookings for deployment planning without a named assigned person
- Absences:
- Vacation, sick leave, and other absences
- Planned Work: Applies only to regular employees and not to temporary staff:
-
Total Available Capacity is:
- Total working hours based on the stored working hours (target hours)
- If no working hours are stored for Saturday or Sunday (normal case), but work is still performed, the available daily capacity is calculated based on the average working time of the other weekdays.
Step-by-Step Example
- Scenario: A team of 5 employees on Monday
- Working time per employee: 8 hours/day
- Total available capacity: 5 × 8 = 40 hours
Example: Bookings for this day:
- A: 8h Project A
- B: 6h Project B
- C: 8h Absence - Vacation
- D: 4h Project C
- E: 8h Project D
- Vacancy: 8h Project D
Calculation:
- Planned work = 8 + 6 + 4 + 8 = 26h
- Absences = 8h
- Vacancy bookings = 8h
- Total demand = 26 + 8 + 8 = 42h
- Total available capacity = 40h
- Utilization = (42 / 40) × 100 = 105%
Result: The team is overbooked by 5% for this day.
Additional calculated metrics:
- Available after planned work = 40 - 26 (work) - 8 (absence) = 6h
- = Vacancies (available) = 6h
- Free capacity =
max(0, 6 - 8)= 0h- This means: Although mathematically -2 hours would be free, the system shows 0 hours free capacity. Negative capacity is not possible – the person is overbooked or fully utilized in this case.
- Missing capacity =
abs(min(0, 6 - 8))= 2h- This means: The difference of 6 – 8 results in -2. Since negative capacity is not directly displayed, the amount of missing hours is calculated: 2 hours are missing on this day to cover all planned tasks.
- = Vacancies (missing) 2h
Interpretation: The 6 hours that are still available after planned work should also be used to cover the 8 hours of vacancy. Since there is not enough capacity for this, it is displayed in the utilization chart as follows:
- 6 hours vacancy (available)
- 2 hours vacancy (missing)
Formulas for utilization calculations:
| What | Description | Formula | Example |
|---|---|---|---|
| Man-hours (MH) (absolute number in hours) | Sum of all planned hours for one person. | = ∑ Booking durations on one day | 2.5h + 5h + 1.5h = 9h |
| Man-Days (relative number: utilization in percent) | the utilization of one person, based on days. | = (Man-Hours / Stored Hours) * 100 | (9 / 8) * 100 = 112.5% |
| Man-Days of workforce | Utilization displayed in planr (daily, weekly, and monthly view) | = (∑ Man-Hours) / (Stored working time * No. of employees) * 100 | (8+9+7+10) / (4*8) * 100 = 106.25% |
| Man-Weeks (relative number: utilization in percent) | The utilization of one person, based on the week. | (MH1+..+MH5) / (SA1+..+SA5) * 100 | (8+7+9+8+10) / (8+8+8+8+8) * 100 = 105% |
| Man-Weeks of workforce | Utilization displayed in planr (yearly view) | In this example with only 2 employees: ((MH1a+MH1b)+..+(MH5a+MH5b)) / ((SA1*2)+..+(SA5*2)) * 100 | In this example with only 2 employees: ((8+9)+(8+8)..) / (2*8+2*8..) * 100 = 102.5% |
Special case for weekend work:
If no working time is defined for Saturday or Sunday (recommended), but work is still performed, the available daily capacity is calculated based on the average of the working times on weekdays. As soon as work is performed on such a day, the daily utilization is automatically over 100%. If no work is performed, no utilization is displayed on this day.
If work is performed on a weekend, this working time is also considered in the weekly utilization of the monthly and yearly views.
Example:
| (in hours) | Monday | Tuesday | Wednesday | Thursday | Friday | Saturday | Sunday |
|---|---|---|---|---|---|---|---|
| Planned work | 8 | 10 | 6 | 8 | 8 | 4 | 0 |
| Stored working time | 8 | 8 | 8 | 8 | 8 | 0 | 0 |
| Daily utilization | 100% | 125% | 75% | 100% | 100% | 150% | 0% |
- Daily utilization Saturday:
- Average working time of weekdays = 8h
1 + (4 / 8) = 150%
- Daily utilization Sunday:
- Utilization is 0%.
Special Cases
- Weekends: As soon as work is performed on a Saturday or Sunday, the utilization for this day is automatically over 100%, since no working time is usually stored for weekends.
- Part-time employees: Part-time positions are currently not directly considered. Best practice is to supplement the reduced workload to 100% with corresponding absence entries.
- Temporary employees: Temporary employees are displayed separately and do not flow into the utilization of regular employees.