Your choice of storage system is an essential part of your warehousing operation, reflecting your inventory rotation and accessibility requirements and storage-density needs of your business. While manual and gravity-fed racking systems are often relatively inexpensive, simple, and efficient for most purposes, there’s a growing demand for automation.
Automatic storage and retrieval (AS/SR) options, such as vertical lift modules (VLM), have several advantages compared with conventional racking systems.
Vertical lift modules allow you to increase vertical storage space when floor space is at a premium, and horizontal expansion isn’t possible. In addition, it improves access to the inventory items stored thanks to warehouse management software (WMS).
Is Automation the Right Choice?
To determine the suitability of automation for your warehouse, you’ll need to consider the layout, existing floor space, clear height, proximity to loading docks, type of inventory you need to store, and other factors.
If the ROI (return on investment) is low or non-existent, then an automated system isn’t appropriate for your particular circumstances. You’ll also need to determine your throughput rate requirements. Throughput refers to the quantity or amount of a product you can deliver to the customer in a specific period. This plays a critical role in warehouse distribution and order fulfillment. By increasing your pick rates, automated systems have a direct positive effect on throughput.
The ceiling height, specifically the clear height, of your warehouse also determines the suitability of a VLM. Clear height refers to the distance from the lowest point on the ceiling to the lowest point on the floor. The lowest hanging point may be a joist, sprinkler, or light fixture.
You’ll need to ensure that the VLM you choose will not interfere with any of these parts and impact your fire or building code compliance. If you have relatively low ceilings, a VLM may not be a suitable choice.
What are the Benefits of Automation?
There are several reasons to consider AR/RS, including vertical lift modules. The first is floor space. Conventional pallet racking systems, including high-density variants, often have significant footprints or require multiple aisles. By taking advantage of vertical space, VLMs can allow you to increase your warehouse capacity without expanding horizontally.
Automated systems reduce the need for manual intervention by workers, either on foot or with the assistance of material-handling equipment. The fewer material handling tasks a worker has to perform, the less likely they will experience a workplace injury. Furthermore, as the VLM stores and retrieves inventory from contained internal columns, there’s no risk of a pallet or inventory tray falling and injuring a worker on the floor.
Aside from increased storage density and worker safety, automated systems offer two additional benefits: increased worker productivity and increased order fulfillment accuracy.
No matter how well trained, human employees can make mistakes. AR/RS have lower error rates than human order pickers, often owing to various types of onboard scanning technology and WMS. Clerical errors due to inaccurately filed paperwork or misjudged picks are significantly reduced as a result.
Vertical Lift Modules
A vertical lift module is a high-density, enclosed system that stores inventory in two parallel columns. In between the columns is an inserter/extractor or lifter. The inserter/extractor moves up and down, retrieving inventory items from trays and placing them in the operator bay, where a worker can pick the items needed. In some models, the operator bay extends outward from the main body of the VLM, providing additional workspace and improved ergonomics.
These systems can increase throughput rates, worker productivity, and security. As VLM systems are fully enclosed, they can be used to more effectively secure high-end merchandise during periods of downtime, such as maintenance or in between shifts, preventing theft. It is far more difficult for a thief to access stored goods in a VLM than a horizontal carousel using baskets.
Manufacturers offer a variety of different VLM systems, each providing a balance of features. For example, in many examples, the system uses servo motors to maintain speed, even when transporting heavy loads.
VLMs are also often equipped with warehouse management software (WMS) that allows you to identify, track, and log inventory. One of the advantages of this software is that it can notify you when the VLM’s inventory is low so that you can restock it promptly. The WMS can also let you know when a product’s expiration date is approaching, allowing you to promptly pick and distribute perishable goods.
A vertical carousel differs from a vertical lift module (VLM). Rather than collecting inventory items using a center extractor, it uses a system akin to that of a Ferris wheel, rotating goods in baskets. A chain usually drives this system. While an efficient and high-density system, vertical carousels do not provide the same speed or selectivity as vertical lift modules. All stored inventory must rotate for you to have access to the basket you need.
Vertical lift modules tend to store heavier inventory items than vertical carousels, but the increased complexity also correlates with a higher cost. Vertical carousels are typically shorter than VLMs, so there are fewer dimensional restrictions.
Vertical Lift Modules vs. Horizontal Carousels
In addition to vertical lift modules, another popular automated storage and retrieval system is the horizontal carousel. The AR/SR that you should choose will depend on many factors, including available floor space and ceiling height. Horizontal carousels require more floor space but can be suitable for warehouses with low ceilings.
A horizontal carousel transports bins or carriers in an oval track in the floor to the order picker. Horizontal carousels are also more economical than many vertical systems, providing a cost-effective option for the budget-conscious warehouse manager.
Another feature that both vertical lift modules and horizontal carousels should have is called pick-to-light. When the order picker scans a barcode, the pick-to-light system uses a series of alphanumeric displays to guide the worker toward the item’s location.
These LED lights then indicate what order needs to be picked and in what quantity, minimizing human error. This order-fulfillment technology is designed to complement semi-automated systems in which human labor is still necessary.
The Bottom Line
At Shelving + Rack Systems, Inc., we specialize in various storage solutions, from simple shelving units to advanced racking systems. While conventional racking and shelving systems are the standard, we also fully embrace the benefits of automation. Automated storage and retrieval systems can reduce the incidence of workplace injuries, protecting workers from falling debris.
To discuss the benefits of an automated system, such as vertical lift modules, call us at (800) 589-7225. We can help you determine what system would best suit your warehousing requirements.