How Many Autonomous Mobile Robots Does Your Warehouse Actually Need?

Sizing a fleet of Autonomous Mobile Robots correctly is one of the most common questions manufacturers ask before investing in automated pallet transport. Granta Automation outlines the key factors - throughput, cycle time, layout and peak demand - that determine the right number of AMRs for a site.

There is no single number of Autonomous Mobile Robots (AMRs) that suits every warehouse - the right fleet size depends on how much needs to be moved, how far, and how quickly. Working it out, however, is more straightforward than it might first appear.

The starting point is understanding the job the robots need to do, usually moving full pallets away from a palletiser and returning empty ones. From there, the cycle time of a single robot - the time it takes to travel to a pickup point, load a pallet, deliver it and return - determines how many moves each robot can realistically complete in an hour.

Charging is rarely the obstacle people expect, since AMRs typically top up automatically during quiet periods rather than needing dedicated downtime. Layout matters more: longer travel distances, narrow aisles and busy shared routes all increase cycle times and therefore the number of robots required to hit a given throughput.

It is also worth sizing a fleet around realistic peak demand rather than simple daily averages, and building in a little headroom so that maintenance or a sudden spike in orders doesn't create a bottleneck. Because AMR fleets are easy to expand, many manufacturers choose to start with what today's operation needs and add robots later as volumes grow.

Granta Automation helps customers work through this calculation in detail, using site-specific measurements rather than rules of thumb alone. To talk through how many AMRs your operation might need, visit our website and contact us today.