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Selecting the Right Carton Flow System Design for Your Warehouse


In warehouse operations, picking speed, fulfillment accuracy, and efficient space utilization are directly related. It’s difficult to attain one without achieving all three, and carton flow systems offer one of the most straightforward ways to do just that.

A carton flow system, also known as carton flow racking, gravity flow, or roller racking, offers a simple and streamlined way to move inventory from the loading side of the shelf to the pick face. Carton flow roller lanes and wheel beds allow inventory to move forward as workers pick from the front of the shelf. This, in turn, enables the warehouse to fit more inventory in a smaller space so workers can fulfill orders faster and with far less movement. The result is increased throughput, more efficient first-in-first-out (FIFO) inventory management, and greater warehouse layout flexibility.

As a dynamic storage option, gravity carton flow systems work in tandem with basic static shelving and/or automated systems to provide a complete fulfillment solution for warehouses. Like any storage system, there is no one-size-fits-all solution, but many can benefit significantly from converting a portion of the warehouse floor to a carton flow configuration. Here’s what you should consider when exploring carton flow for your warehouse.

Is Carton Flow Racking Right for Your Warehouse?

Every fulfillment center has its own unique needs, so it’s wise to consider the specifics of your operation before making any changes to your layout and shelving setup. Factors such as inventory size, SKU variety, and order picking frequency all play a role in determining what types of storage systems are right for your warehouse. Below are the top 4 considerations for determining whether carton flow racking is right for your warehouse.

1. Consider Your Throughput

First and foremost, carton flow systems are designed for medium to fast movers — inventory that cycles through the warehouse quickly and doesn’t sit on shelves for long periods. These are the products that workers pick most frequently, and static shelving severely limits their ability to do so efficiently. You’re left with only two options: Either workers must constantly move inventory manually or you’ll have to offer more pick faces for each fast-moving item. Both choices translate to higher labor and space costs.

Dynamic storage solutions allow those fast-moving items to move seamlessly as workers pick from the front of the shelf. That means your top products can ship out much more rapidly. Since fast and medium movers make up a significant portion of most inventories, carton flow racking is likely a good choice for your warehouse.

2. Evaluate Your Order Picking Methods

Another way to assess your need for a carton flow system is to examine the current state of your order picking system. Do you regularly find that employees have to travel across the warehouse to fulfill orders? How frequently are they left picking products that aren’t readily available at the pick face? Are some aisles congested with too many workers picking different products? 

These are common problems in today’s omnichannel fulfillment environment, and they’re signs your warehouse team could benefit from a carton flow system. Gravity flow racks allow you to better organize your shelves and optimize picking workflows for products that require regular access. Converting a portion of your warehouse to carton flow could increase your operational efficiency by 75% or more.

3. Assess Storage Density Needs

If your warehouse is bursting at the seams, that’s the ideal time to reconsider your current industrial shelving setup. Before you sign a lease on a larger space, take the time to assess your current storage density. You may benefit from converting some of your existing static pallet shelving into carton flow shelves. 

Carton flow shelves allow you to consolidate inventory into a smaller footprint. Whether you need to organize shelves for full case picking or each picking, carton flow enables you to fit more products within reach.

4. Determine How Much Flexibility You Need

Carton flow racking solutions are dynamic in more ways than one. Besides allowing for streamlined inventory movement, they’re also fully customizable and adjustable as business needs evolve.

Carton flow systems can be built with a variety of roller and wheel bed configurations to accommodate lighter or heavier products or to allow more flexible inventory sizing within the same picking area. They can also be customized to suit different types of fulfillment operations, from retail to manufacturing. If flexibility is critical for your operation, carton flow may be the right choice.

Get The Definitive Guide to Carton Flow Storage and The Ultimate Order Picking Checklist. Download the guide today!


Carton Flow System Design Best Practices

If you decide to convert some of your warehouse storage into carton flow, there are several important factors to consider. By taking the following steps, you can ensure you design the right setup for your needs:

  • Analyze SKUs: Take a complete inventory of all SKUs, including the total quantities, dimensions, and sizes. This provides a comprehensive view of what you’ll need in terms of which SKUs will be best suited for carton flow and how much of your space should be dedicated to it.

  • Choose system capacity: SKU weights are particularly important for planning shelf types, as different track types are designed for light, medium, and heavy inventory. You’ll want to store like with like, so it’s essential to understand how much stock you have in each weight class.

  • Select track type: Armed with a comprehensive view of your inventory, you can choose the right mix of track types, including steel or aluminum roller lanes, plastic wheel beds, or skatewheels. Carton flow rollers and wheel beds are offered in a variety of options to accommodate light to heavy loads. Uniform roller beds like SpanTrack Lanes are ideal for housing items of similar width, while SpanTrack Wheel Beds offer more flexibility for mixed inventory sizes.

  • Consider inventory replenishment needs: Carton flow systems are designed to accommodate FIFO restocking and picking, so workers can simultaneously pick from the front and restock from the rear. Depending on how quickly your inventory moves, there are ways to make this system even more effective. UNEX offers a variety of carton flow accessories, such as infeed guides, guard rails, and guide rails, which can help make this process as smooth as possible.

  • Evaluate ergonomic requirements: Shelves can be customized even further based on your inventory types and picking requirements. For instance, angled shelves work best for each picking and can be combined with pick trays and/or knuckled ends for easier access, while straight shelves are better suited for case picking.

  • Determine broader workflow integration needs: Finally, your carton flow configuration can be tailored to accommodate various picking methods. Consider whether you need to incorporate barcode scanning or a pick-to-light system and design your shelf setup accordingly.


Optimizing and Integrating Your Carton Flow System

Converting a portion of your warehouse to carton flow can represent a substantial investment — and a significant upgrade — but it’s critical to design a system that suits your needs. The best carton flow systems are fully customizable from the broader configuration and layout to the details of carton flow accessories for ergonomic picking. Opt for a system that will not only meet today’s business needs but also scale and adapt for tomorrow’s.

It’s also important to consider how your carton flow racks will integrate within your entire storage and fulfillment system. Most operations include other critical fulfillment components, from static pallet racks to conveyers and lift systems. Your goal should be to optimize workflows and create synergy across all your equipment.

With all these factors in mind, you’ll be in a better position to evaluate the total return on investment (ROI) of your carton flow system. Companies like Cutter & Buck found that even the cost of 4,000 SpanTrack wheel beds was well worth it in light of the significant uptick in picking speed. As you weigh the cost of conversion, consider how quickly you can earn back that investment by creating a more efficient operation.

Work with UNEX: The Carton Flow Authority

Adding carton flow to your warehouse can transform your operations by increasing fulfillment speed and accuracy and enhancing your inventory management. For many warehouses, it’s a key component in a comprehensive operational optimization plan.

Ultimately, however, your carton flow system is only as good as the thought you put into it and the quality of the equipment you choose. SpanTrack carton flow from UNEX offers best-in-class components and fully customizable solutions. Contact the experts at UNEX to build your ideal system or start designing your own with our SpanTrack product configurator today!

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