Estimate the number of mobile warehouse robots required to complete a daily workload. The model combines task demand, average cycle time, scheduled hours, productive utilization, charging downtime, and a spare-fleet allowance. Results include the operating fleet, purchased fleet, capacity per robot, and utilization at the rounded fleet size.
The purchase fleet is a deterministic planning estimate based on average task time. Congestion, queueing, and uneven task geography can increase the actual requirement.
Validate the result with a site simulation before procurement, especially where robots share narrow aisles, elevators, or workstations.
For 6,000 tasks, a 3.2-minute cycle, 16 operating hours, 82% utilization, 12% downtime, and a 10% spare allowance, each robot handles about 216.5 tasks/day. You need 28 operating robots and 31 robots to purchase.
A fractional robot cannot complete the remaining workload, so the required count is always rounded up.
It should not be. Use utilization for dispatch and workflow losses, and downtime for unavailable charging or maintenance time.
Base it on observed failure rates, maintenance turnaround, demand variability, and the service level your operation requires.
Not explicitly. Congestion should be reflected in measured cycle time or validated through a discrete-event simulation.
Yes. Run each shift separately if task volume, cycle time, or available robots differ by shift.
| Input | Unit | Role |
|---|---|---|
| Tasks per day | tasks | User-provided planning input. |
| Minutes per task | min | User-provided planning input. |
| Operating hours per day | hours | User-provided planning input. |
| Productive utilization | % | User-provided planning input. |
| Charging/maintenance downtime | % | User-provided planning input. |
| Spare fleet allowance | % | User-provided planning input. |