Mini-load

A narrow crane runs along a tall rack and fetches plastic bins, trays or cartons instead of whole pallets. It takes each one to the end of the aisle, where a person or a conveyor collects it, and later puts it back. It suits small items kept in standard bins, and this type of storage is called a mini-load.

Mini-loads handle light loads, typically bins on a common European footprint of 600 by 400 millimetres, though sizes differ between makers. The person picks from the bin at a station and the bin goes back into the rack.

One crane serves one aisle, so a very busy aisle can become the limit on how much can be moved. Shuttle systems answer that by putting a small vehicle on every level.

When it pays off

It pays off for many thousands of small items picked in lines of a few units, where a person picks from the bin brought to a station. It suits operations with tight floor space and a steady range. It pays off less for a very busy single aisle, for large goods, and for operations that must change their range often, since the rack and the bins are built for a stable set of sizes.

What the warehouse system does with it

The warehouse system sends retrieve tasks for a bin to a station, naming the bin or its location, and receives a confirmation when the bin has arrived and when it has been put back. For stock moves, the WMS or the control layer decides which free place a returning bin goes to, and the machine reports the place it used. If a bin does not fit or is damaged, the machine reports a fault and the WMS decides what happens to the order.

Who makes it

Daifuku, Gebhardt, Jungheinrich, Mecalux, SSI Schäfer, Stöcklin

In alphabetical order. Not a ranking or a recommendation.