Why the most-stocked building is rarely the most productive.
A warehouse is easy to judge on a single number: how much it holds. It is a tidy figure, it appears on every site report, and it rewards filling the room.
It is also the wrong number to optimise alone. The job of a distribution warehouse is not to store goods. It is to move them — and storage and movement pull against each other sooner than most layouts admit.
Density and throughput share the same floor, and they compete for it. Narrowing aisles and stacking deeper wins more pallet positions per square metre, which looks efficient on paper. The cost is paid in motion: a forklift takes longer to reach a given location, congestion builds at the pick face, and a deeply nested pallet has to be dug out from behind others before it can ship.
The building that holds the most is therefore often the one that ships the slowest. Cube utilisation rises while picks per hour fall, and the report that celebrates the first number never shows the second.
The balance also depends entirely on what a site is for, which is why a single template across a network is a quiet mistake. A regional hub consolidating and forwarding full pallets can run dense, because goods enter and leave in large, predictable units. A distribution warehouse breaking bulk into individual customer orders cannot, because it lives or dies on the speed of the pick — and speed needs room to move.
FMC operates both kinds within the same network: 13 regional logistics hubs feeding 18 distribution warehouses. Designing the warehouse to the same density as the hub would choke exactly the buildings whose entire purpose is fast, fragmented outbound flow.
Profile drives the answer more than any rule of thumb. A site dominated by fast-moving health and wellness or beauty lines, ordered in small quantities many times a day, needs accessibility above raw capacity. A site holding slower home and lifestyle stock that turns a few times a year can afford to pack tightly, because the cost of digging out a pallet is rarely incurred. The same square metre is worth a different layout depending on what passes through it.
Real warehouses hold a mix, and the mix shifts with the season. A layout fixed at commissioning and never revisited drifts out of step with the goods it actually handles.
FMC’s practice is to treat warehouse design as a setting to be tuned rather than a state to be reached. Slotting is reviewed as volumes move, fast lines are kept near the dispatch doors, and density is conceded deliberately where flow earns more than storage saves. The aim is not the fullest building. It is the one that empties and refills with the least friction.
Capacity is what a warehouse can hold. Performance is what it can let go of, and how quickly.