Sizing and specification
Where evaluations go wrong
Sizing on payload alone
A two-tonne machine does not move every two-tonne load. An offset centre of gravity, an overhanging load or an over-tall one all overturn the choice.
Using rated speed
Two metres per second is flat out in a straight line. With turning, slowing, passing and queueing, 1.2 m/s average is a good result.
Ignoring floor works
Gaps, steps, ramps and grating do not show on a drawing. Found on site, remediation can exceed a tenth of the project.
Assuming the network
“We have WiFi” and “the WiFi supports multi-robot scheduling” are different statements. Signal strength, roaming time and packet loss must be measured.
Underestimating carrier work
Wrong ground clearance, no docking plate, no code — across several hundred racks that is real work and real time.
Counting only the robots
Chargers, the scheduler, accessories, implementation, training and spares together commonly add 30–50% to the machines.
Ignoring the peak
A fleet sized on the average jams solid at the peak.
Four items are most often left out: floor works, carrier modification, interface development and the first batch of spares (typically 5–10% of machine value). The full list also covers the machines, chargers, scheduler and server, accessories, implementation, network and power.