Vertical lift module
VLM
A tall steel cabinet holds trays stacked from floor to ceiling, with a lift in the middle. When you ask for an item, the machine brings the right tray to a small opening at working height, so nobody climbs, walks or searches. Many small items fit on a few square metres of floor; this machine is called a vertical lift module (VLM).
The trays carry bins or loose parts, and the machine knows which tray holds which item. Because the opening is at a comfortable height and the rest is enclosed, stock also stays under control and out of sight, which is why it is common for tools, spare parts, electronic components and small medical items.
A vertical lift module is a close relative of the carousel: both bring the stock to the person, but the lift module uses the height of the building where a carousel uses the length of the floor.
When it pays off
It pays off with many small, valuable items, little floor space and a ceiling that nobody uses. A few hundred to many thousands of different items, picked a few at a time, is the typical profile, and it works best as a fixed pick point next to a packing or kitting bench. It pays off less for bulky or heavy goods, for very fast single-line orders where the operator waits at the opening, and in a building too low for a tall cabinet. The machine and its installation are a fixed investment, so a stable range helps.
What the warehouse system does with it
The warehouse system gives the instructions and the machine reports what happened. Typically the WMS sends a task, such as bring the tray holding article X to opening 1 for order Y, and receives a confirmation of the quantity picked. For putaway it asks the machine for a free compartment and records which tray and position the stock went to. Many lift modules come with their own control software, so the link is usually an interface between two systems rather than a WMS driving the lift directly.
Who makes it
Effimat, Electroclass, Hänel, Kardex, Modula, SSI Schäfer
In alphabetical order. Not a ranking or a recommendation.
In practice
A supplier of dental equipment keeps a few thousand small spare parts, most smaller than a fist. They stood on shelving across a large room, and the pickers walked kilometres a day. Two cabinets, as tall as the building allows, now take a fraction of that floor. The picker stands at one opening, the right tray arrives, a light bar marks the compartment, and the part is picked.
Further reading
Ready to see BizBloqs on your own process?
Book a demo and we will walk your warehouse and order flow end to end — inbound, storage, picking, shipping, returns — and tell you honestly what BizBloqs would change.
Two questions about your own operation
How many of your articles sit in a pick location they empty less than once a month?
Part one: Laying out a warehouse does not start with the racking
After your last integration, how many systems hold a stock quantity for the same item? Name them.