What is a Vertical Lift Module (VLM) - also known as a "shuttle"? A VLM is a goods-to-person or goods-to-man automated storage and retrieval system (ASRS). The VLM consists of a series of trays to hold goods which are stored in front and behind a vertical column; an ergonomically positioned work counter; and an inserter / extractor device, that moves vertically through the column's center, moving trays between the storage locations and the work counter.
The height of each tray and its contents is automatically scanned as a tray moves from the work counter onto the the inserter / extractor unit. Each tray is then stored in the minimum amount of space within the VLM. The VLM's controls allow users to use different storage schemes to best fit each application’s needs. A unit can have specific trays stored close to or farther from the work counter, based on tray usage. You can also program individual trays to allow a set maximum item height in order to maximize storage density. Likewise, a "shuffle" feature will automatically scan every tray's height and re-store each tray in the unit within the least amount of space ... creating additional capacity.
VLMs are used independantly or in "pods" or workstations. Integrated software, pick-to-light indicators, weigh scales, conveyor, ergonomic assist equipment, bar code scanners and printers are just some of the ancilliary products that can be used in a dynamic storage and retrieval system workstation.
Using Vertical Lift Modules for Batch Picking Operations
Needless to say, having one operator at each VLM waiting for the inventory to be delivered isn’t going to achieve the highest throughput rates. Instead, one person should service several VLMs. As each tray is delivered, the operator picks the inventory and then hits the task complete button. That VLM will then re-store the picked tray and retrieve the next required tray while the operator is picking an item from a different VLM in the "pod".
Optional pick-to-light (TIC lights) and even laser pointers can be incorporated into the VLM's work counter to direct the operator to the picking location for each item on the presented tray. The lights can also diplay the quantity to be picked, lot number and other related information. Typically, a batch station of some form is used in conjunction with VLM pods. The batch station often consists of a conveyor with mounted put light displays which are PC-driven. Each light position on the batch station is adjacent to a tote or box. The tote may contain only an individual order or can be divided into multiple cells with different orders - depending on the SKU size, physical characteristics and quantities on hand.
Often, VLM order picking systems can attain rates up to 375 lines per-hour-per-operator. The tremendous amount of floor space savings, the labor savings and item protection offered by a Vertical Lift Module order picking system can be an ideal solution for many application and facility requirements.
Likewise, VLMs can be integrated into a pod of other equipment such as horizontal carousels, pick-to-light flow rack, shelving, etc. - creating what's known as a universal workstation. This configuration focuses on eliminating labor and utilizing the best technology for each SKU's characteristics and picking velocity. The fastest movers go into the pick-to-light flow rack, medium and fast movers go into the horizontal carousels and the slow and medium movers go into the VLMs. The beauty of this configuration is that one workstation can be operated by one order picker in a very efficient manner.
Vertical Lift Module Benefits
First and foremost, VLMs can save 85% of otherwise wasted floor space and often up to 90%+ in facilities with 35+ foot ceiling height. The integrated software and pick-to-light system can help provide accuracy levels in the 99.99%+ range while saving up to 2/3s the labor required to pick from shelving and cabinet systems. VLMs eliminate wasted walking, searching, bending and reaching operations while providing increased throughput and productivity. Because of its secure enclosure and password protected operator access, VLMs are an ideal storage medium for high value or controlled inventory. (The software can maintain a secure log of who operates the machine and which trays they access.) VLMs can be configured to have multiple work counters on the same or even different floor levels. This means multiple operators can pick or store items at the same time. Finally, the VLM's modularity, the ability to modify its height and its ability to automatically store variable height items in the least amount of space makes it efficient, relatively easy to reconfigure and relocate, easy to manage and easy to train users to operate it.
Popular VLM Brands and Trademarks (Not ISD trademarks):
Just a Few VLM Applications: