Also in: Disaster Response and Recovery
Dock Door Count from Arrivals and Turn Time
Converts trucks and turn time into door-hours and a door count at a practical utilisation.
Example
You enter
- Trucks per day 60
- Operating window (hours) 10
- Average turn time (min) 55
- Practical utilisation (%) 65
- Share of arrivals in the peak (%) 40
- Peak window (hours) 3
- Turn time after improvement (min) 40
You get
- Door-hours required 55.0 door-hours a day
- Doors at full utilisation 5.50 doors -- a figure no dock achieves
- Doors on the daily average 9
- The peak window 24 trucks, 22.0 door-hours
- Peak door hours 22
- Doors the peak requires 12
- Peak shortfall doors 3
- At the improved turn time 9
- Doors saved by turn time 3
Checked against published worked examples from: 4Front Engineered Solutions (Kelley); W.B. McGuire (a division of Systems, LLC).
Details, formula, and sources
Scopeon the daily average and again over the peak window. The worked dock needs 12 doors for the peak against 9 on the average, and 15 minutes of turn time saves 3 doors.
Formula or tableDoor-hours = trucks x turn time; doors at full utilisation = door-hours / operating hours; doors required = that count / practical utilisation, rounded up; the peak is computed the same way over the peak window.
Source and editionThe facility's own arrival data, turn-time measurement, and yard and detention practice.
Free accessQueueing arithmetic only; no purchased standard is required to reproduce it.
What governsEstimate. AHJ and licensed professional govern.
API field namestrucks_per_day, operating_hours, turn_time_min, utilization_pct, peak_arrival_share_pct, peak_window_hours, improved_turn_time_min, door_hours, doors_at_full_utilization, doors_required, peak_trucks, peak_door_hours, peak_doors_required, peak_shortfall_doors, improved_peak_doors_required, doors_saved_by_turn_time
- Practical utilisation 60 to 70% is the ordinary planning range; utilisation below 100% is not slack but what makes the dock workindustry practice, entered as an input
- Peak a share of arrivals in a stated window; sizing on the daily average understates the requirement by the peaking factorfacility arrival data