There are various approaches to storing and managing inventory for both internal and external distribution. Some methods, like static shelving, use straightforward, low-tech setups. Other methods are more advanced, often involving integrated computer systems and, in some cases, robotics.
This second group features a range of automated storage solutions, including horizontal carousels, vertical carousels, vertical lift modules (VLMs), ASRS or shuttle systems, and grid systems.
Static shelving
Static shelving is one of the most widely used methods for storing and managing inventory, mainly because of its low initial cost. However, the fixed dimensions of these shelving units mean they cannot be modified to make the best use of warehouse space. Additionally, when inventory is stored on shelves, pickers must walk up and down the aisles to fulfill orders, which is time-consuming, prone to errors, and physically demanding with all the walking, bending, and repetitive motion. Static shelving can also pose safety risks, as operators can only pick items within their line of sight. To reach higher, they may need to stretch or use ladders, both of which increase risks and slow down the picking process.
Vertical carousels
Vertical carousels are automated storage solutions that operate on the vertical axis. The mechanism that drives a vertical carousel is similar to the mechanism that drives a Ferris wheel; however, rather than rotating on a circular path, as a Ferris wheel would, the shelving units in a vertical carousel move up and down along a tall, oval path, creating a compact footprint that saves floor space while more than doubling the storage capacity compared to traditional static shelving.
The footprint, measured at the unit’s base, typically spans five to seven feet in depth and 10 to 12 feet in width. At SencorpWhite, we offer customized options to fit even smaller, unique spaces. When designing a vertical carousel, we consider your current storage area and use this to guide decisions about pan depth, width, and height. The height is adjustable, so for smaller items, we can make shelves denser, and for taller items, we can space shelves farther apart. This approach maximizes storage density while minimizing the unit’s footprint. Usable storage refers to what can be stored on the shelves or in the pans, and SencorpWhite’s vertical carousels boast one of the smallest motor footprints in the industry, meaning the usable storage density closely matches the unit’s total cubic volume.
Vertical carousels are increasingly popular across various sectors, from aerospace and manufacturing to retail and pharmaceuticals. Beyond increasing storage density, they significantly enhance warehouse efficiency. Similar to a horizontal carousel, a vertical carousel’s internal mechanism is integrated with computer software, creating a true “goods-to-person” system. When a product needs to be picked, the software instructs the carousel to bring the correct tote to the operator at the workstation, speeding up pick times, improving accuracy, and enhancing ergonomics.
An additional benefit of SencorpWhite vertical carousels is the emergency hand crank for manual operation. In case of a system malfunction, operators can disengage the brake and use the hand crank to rotate the mechanism, allowing for loading or unloading until the system is fully operational again.
Vertical lift modules
Vertical lift modules (VLMs) operate similarly to vertical carousels, moving trays vertically to an operator. The operator views the tray, selects the needed item, and presses a completion button, which signals the system to retrieve the next tray. VLMs generally support heavier loads than vertical carousels, making them well-suited for bulkier items. SencorpWhite’s VLMs come in both single and multi-column configurations, with one unit capable of providing up to seven picking windows. Some models even offer windows on both the front and back, allowing picking and restocking to occur simultaneously.
Both vertical carousels and VLMs feature dynamic shelving and light-directed picking. When a tray reaches the operator, a shutter drops at the back, displaying an image of the item along with its location on the tray and additional details like SKUs, required quantities, and inventory updates. For vertical carousels, all of this information is conveniently displayed on the marquee bar positioned in front of the operator.
Shuttle systems
Some automated storage and retrieval systems (AS/RS) utilize a shuttle, much like an unmanned forklift, to navigate between static shelving units. The shuttle can move both vertically and horizontally and is programmed to reach specific shelves and retrieve items. Shuttle systems are commonly used to manage the internal or external distribution of full pallets or cases, as well as heavy items like motors or other components required for assembly processes.
Grid systems
Grid systems organize inventory by placing all items in totes within a standard, enclosed unit. A robot is then programmed to retrieve specific items as needed. The essential factor for grid systems is that each item must fit within the grid’s dimensions, which allows for very compact storage. To ensure that the robot has easy access to required items, inventory is repositioned within the grid at the end of each shift, placing the most frequently needed products near the top. This process is similar to adjusting tiles on a Rubik’s cube. Grid systems can operate continuously, maximizing slotting efficiency. They are ideal for warehouses that prioritize storage density over retrieval speed.
Comparing Costs Across Different Automated Solutions
Determining the true cost of an automated system involves assessing ROI and the specific storage or distribution challenges you aim to address. For instance, while grid systems might have the highest upfront cost, they can offer the lowest cost per cubic foot of storage. On the other hand, well-sized vertical carousels and VLMs can also provide compact storage solutions. Horizontal carousels tend to fall in the mid-range price per cubic foot but stand out for their picking speed and accuracy, making them an efficient option in many scenarios.