Vertical Lift Module
How does a VLM differ from traditional shelving?
A VLM automates storage and retrieval by bringing the requested tray to an operator at an ergonomic access window. Traditional shelving requires workers to travel to the location, search for the item, and manually pick it, which adds travel time and increases the chance of mispicks.
What is the core mechanism that retrieves trays?
A VLM contains two vertical tray columns and a central lift/extractor. When a tray is requested—typically via barcode scan or WMS/ERP command—the extractor moves vertically, selects the tray, and carries it to the access opening for the operator.
Which inventory types are best suited for a VLM?
Small to medium parts, fasteners, electronics, tooling, MRO supplies, books, and other dense SKU sets with frequent access fit best. These items benefit from compact vertical storage and quick goods-to-person retrieval, while large or non-uniform loads are better handled by other storage solutions.
A Vertical Lift Module (VLM) is an enclosed automated storage and retrieval system (ASRS) that stores inventory on trays stacked in two vertical columns. A central extractor/elevator moves vertically inside the unit to retrieve a requested tray and deliver it to an ergonomic access window. Commonly used in manufacturing, warehousing, and raw-material tracking for small parts, tools, and MRO items.
On the shop floor, a VLM works as a goods-to-person buffer for fast-moving, high-value, or controlled SKUs. When an operator scans a part request in the WMS/ERP or on the VLM controller, the unit identifies the tray location, retrieves it, and presents it at waist height. This cuts travel time, improves picking accuracy, and reduces ergonomic strain because workers do not bend, reach, or walk long aisles. Because the module uses building height rather than floor area, it can reclaim up to 85–90% of the space compared to traditional shelving. For raw-material control, the VLM becomes a controlled issue point: trays are assigned to lots, bins, or kit components, giving tighter traceability and visibility of on-hand stock. When integrated with inventory software, replenishment, putaway, and issue transactions happen in real time, keeping line-side supply aligned with production demand.
Tray Jams and Stockouts: Mixed-size parts that exceed tray payload, height, or weight limits can cause trays to jam, skew, or become inaccessible, halting retrieval cycles and creating hidden WIP or line-side stockouts.
Master-Data Mismatch: When item dimensions, locations, or unit-of-measure data are wrong in the WMS or ERP, operators are directed to the wrong tray, putaway validation fails, and inventory records drift, causing picking delays.
Receiving Bottleneck: If incoming material is not staged, counted, and slotted before putaway, the VLM becomes a constrained receiving point; operators wait, replenishment queues build, and production starves even though stock is physically on site.