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Robot Fleet Fleet Sizing Calculator

The Robot Fleet Fleet Sizing Calculator estimates the number of robots required to support a daily task workload using average per-robot throughput, productive operating hours, expected utilization, and an explicit redundancy allowance. It is intended as a general planning model for robot fleets when the work can be expressed as repeatable completed tasks and a representative tasks-per-hour rate is available.

The calculator first determines the workload-based base fleet and rounds it up to a whole robot. It then applies the requested redundancy percentage and rounds up again, producing a total fleet target that includes extra capacity for resilience. This can help teams separate workload demand from their spare-capacity policy instead of hiding both inside one utilization assumption. The model is deliberately simple and does not simulate routing, charger queues, robot heterogeneity, shift-level demand peaks, or maintenance schedules. Use measured operational data or discrete-event simulation when those factors drive the final fleet decision.

Robot fleet sizing inputs

tasks/day
tasks/hr
hr/day
%
%
Result
—
Estimated total robots required
Base workload fleet—
Added redundancy robots—
Effective capacity per robot—

1. Enter required daily tasks
Use a consistent definition of a completed task for the workload target.

2. Set average robot productivity
Enter completed tasks per robot per productive hour for representative operating conditions.

3. Define productive hours
Use the daily hours during which each robot can contribute to the counted workload.

4. Apply expected utilization
Account for normal idle time, dispatch gaps, congestion, and other operational losses.

5. Choose a redundancy allowance
Enter the percentage of extra fleet capacity you want beyond the rounded workload requirement.

6. Review total fleet size
The total result rounds up to whole robots after applying the redundancy allowance.

Base fleet = ceil[Daily tasks ÷ (Tasks per robot per hour × Productive hours × Utilization)] Total fleet = ceil[Base fleet × (1 + Redundancy allowance)]

Utilization and redundancy are entered as percentages and converted to decimals. Both fleet calculations round upward to whole robots.

This model assumes a representative average productivity rate and a percentage-based redundancy policy; it does not explicitly schedule maintenance or charging.

What the result means

The main result is the whole-number robot fleet target after adding the selected redundancy allowance to the workload-based minimum.

A percentage redundancy rule is a planning convention, not a substitute for reliability analysis when service continuity requirements are strict.

Given

  • 2,800 tasks per day
  • 13 tasks per robot per hour
  • 15 productive hours per day
  • 80% utilization
  • 12% redundancy allowance

Calculation
Effective capacity per robot = 13 × 15 × 0.80 = 156 tasks/day. Base fleet = ceil(2,800 ÷ 156) = 18. Total fleet = ceil(18 × 1.12) = 21 robots.

Result
21 robots

Eighteen robots cover the modeled workload; the redundancy policy increases the planning target to twenty-one.

Why is redundancy separate from utilization?

Utilization represents how much of normal productive capacity is used, while redundancy adds explicit fleet margin beyond the workload requirement. Separating them makes the assumptions easier to audit.

Can redundancy be zero?

Yes. A zero setting returns the rounded workload-based fleet without a separate spare allowance. That may still include unused capacity created by rounding.

Should maintenance downtime be reflected in utilization or redundancy?

It can be represented in either approach depending on your planning method, but avoid counting the same expected downtime twice. A reliability-driven spare policy may be more appropriate when maintenance events are discrete and consequential.

What if different robots have different task rates?

This calculator assumes one representative average rate. Mixed fleets are better modeled by robot type or with a capacity model that separately represents each group.

How is this different from the AMR fleet sizing calculator?

This version is a general robot-fleet model with an explicit redundancy percentage. The AMR-specific version uses a peak demand factor and is framed around mobile-robot move throughput.