Is a VLM Right for Your Operations?

Vertical Lift Module

When it comes to automated storage and retrieval systems (AS/RS), there are seven main types to choose from, which can make it confusing to determine the best solution for your operation.

All fall under the ASRS umbrella, meaning they typically serve to replace large shelving areas in your facility. Each system saves you floor space, improves safety, and increases productivity, which is in demand today, particularly with the labor shortage.

You can find an AS/RS in both warehousing and manufacturing applications.

The seven main types of ASRS include:

  • Carousel (vertical and horizontal)
  • Vertical lift modules
  • Mini-load ASRS
  • Unit-Load ASRS
  • Robotic shuttle-based ASRS
  • Robotic cube-based ASRS
  • Floor robots

Each ASRS variation serves a different purpose. This article focuses on the second type listed above, the vertical lift module (VLM)—what it is and its best applications.

Like other types of AS/RS, a VLM helps you save floor space. In this case, VLMs hold vertical trays in an elevator-like system. There is an inserter/extractor in the middle of the tower, with an enclosed column of the trays on either side.

When it is time to pick an item, an operator tells the VLM to find it, and the inserter/extractor picks the right tray, then delivers it to the operator. To return a tray, the system may have a fixed position—meaning it goes back to its same spot—or a dynamic position. In this case, the system will adjust automatically when the inventory changes. Dynamic positioning can be ideal if your facility has a number of odd sizes or long, thin items.

If you are currently operating in a building that is bursting at the seams but don’t want to invest in additional space, a VLM can be a good way to utilize your area better and stay put. You can store thousands of SKUs in a VLM, depending on your needs. The trays can hold cases, totes, and large items. By using dividers within the VLMs, you can increase the number of SKUs you want to store.

Most VLM systems come equipped with basic controls and their own inventory handling management system. They can also be integrated easily into an existing warehouse management system (WMS), allowing for quick start-up and operations.

A VLM’s nearest ASRS cousin is probably the vertical carousel. Unlike a VLM, a carousel manages one tray at a time, making it an option for optimizing small, stored items so that all parts to be picked are on the same shelf. The vertical carousel’s labor savings can be a true benefit, but at ceiling heights greater than 30 feet, it simply makes more sense to go with a VLM.

However, if speed isn’t the name of the game in your operations, but labor savings are, then it is worth considering.

You can expect labor savings from 60 percent to 70 percent, with accuracy levels nearing 100 percent. While a VLM’s return on investment (ROI) will vary by operation, you can expect it to range between 12 to 18 months.


For more information about the ASRS group:

Further Reading:

Understanding ASRS Software Integration

ASRS Is Perfect For Social Distancing

Podcast: How Does An ASRS Solution Differ And Complement AMRs/AGVs?

ASRS As A Solution To The Labor Shortage

Using ASRS To Offset The Labor Shortage

Lights Out: The Role Of ASRS