Why warehouses moved off rails
For decades, high-throughput warehouses relied on fixed infrastructure: conveyor belts, sortation chutes, and sometimes rail-guided shuttles bolted to a specific floor plan. That infrastructure is fast and predictable once installed, but it is also a long-term bet on a layout staying the same. If order profiles shift, a new product line needs different storage density, or a facility needs to expand into a neighboring bay, a fixed conveyor system has to be physically torn out and rebuilt. That is slow, expensive, and it takes the whole zone offline while it happens.
Autonomous mobile robots (AMRs) trade that upfront rigidity for reconfigurability. A fleet of independent robots doesn't care where the shelves are this month, it just needs an updated map and a new set of pick locations. Adding capacity means adding more robots rather than more concrete and steel. This is why the shift toward AMR fleets tracks so closely with warehouses that face seasonal demand swings or frequently changing SKU mixes: the flexibility is worth more than the marginal efficiency a purpose-built conveyor line could offer for a layout that won't stay fixed anyway.