Carton flow systems are ideal—if your warehouse is properly suited for them. By using gravity, they increase space utilization, worker productivity, and operational efficiency. So, is the racking type the right solution for your operation? This guide will help you decide.
Keep reading to learn everything you need to know about carton flow systems, and trusted partners to help you execute one successfully.
What is Carton Flow?
Carton flow rack systems help warehouses decrease space utilization while enhancing efficiency and organization. When the front load is removed from the system, the loads behind it “flow” forward.
Flow racks can have multiple shelves and be used in several lanes. In most warehouses, one SKU is assigned to each lane for efficient locating and picking. They can also be customized with various-sized rollers that can vary in materials and types to suit every unique racking system.
The best part of carton flow systems is that they require no power. The next item rolls into place automatically as the front item is picked. Flow racking is ideal for first-in, first-out systems for inventory rotation.
Advantages of Carton Flow Systems
Using gravity to shift your racking loads offers warehouses a variety of advantages. Despite its higher initial cost, carton flow systems reduce labor costs over time by reducing walk and search time for workers. It’s been found that workers will spend approximately 85% of their time picking and only 15% walking or searching with these systems.
Another benefit is that flow storage is highly compatible if you’ve already implemented modern automation solutions, such as voice picking or pick-to-light. In tangent, restocking speed can be tripled or doubled, as restockers can be more efficient with sliding loads into the back of the rack (we’ll discuss full-case vs. split-case picking later!). As for space, because stocking and picking occur in opposite lanes, the two activities do not interfere with one another. This improves not only workflow but overall storage density optimization.
Assessing Storage and Picking Systems
Before you make any changes to how you organize, pick, and load your inventory, of course, it’s best to assess all the factors that will affect your operation. Here’s an in-depth review of the most common solutions to appropriately select the one that’s right for your warehouse’s workflow.
First in, First out (FIFO)
Aptly named, the first loads to be loaded are the first to be picked in the first in, first out system. The FIFO system is most popular for degradable products that spoil, have expirations, or need rotation for other reasons. Most common types of products are food, or medicines.
Last in, First out (LIFO)
As you can guess, last in, first out is used for inventory, where the last load, is the first to go. LIFO is most commonly used for non-perishable items such as building materials, chemicals, and petroleum products, where the date of manufacture or shelf life is less critical.
Automated Systems and Carousels
Automated systems work with integrated technology to deliver products to pickers when called upon via carousel or other mechanisms. These solutions are the most expensive to install and implement, but they can be cost-effective over time in the right operation. They’re used for high-volume operations and are customizable to adjust to changing markets, too.
Selective Picking Systems
Selective picking systems refer to pallets that are always available to pickers. Most commonly, the loads are stored in static shelving, where order pickers are tasked with manually finding and picking items. The system is not ideal for items with expirations, but best for those without.
Block or Floor Stocking
One of the simplest yet inefficient solutions for inventory storage is stocking or “blocking” your inventory on the floor in boxes or totes. While cost-effective and inexpensive to execute because no racks are required, you can potentially damage inventory due to poor ventilation or crushing items during movement.
Carton Flow Rack Pick Types
Carton flow rack systems are suitable for full or split case picking. Let’s review both next.
Full case picking
When one load (or tote) is picked and sent further into the process, it’s known as full-case picking. They’re often picked from shelving, racks, or pallets, but carton flow is the most efficient and organized for the selection type. It’s also far more straightforward than split-case processes.
Adding rollers to existing pallets can optimize first-in, first-out storage lanes, which is also ideal for full-case picking scenarios, where one SKU is stored per lane.
Split case picking
With split case picking, individual items are picked from the open bins or loads after “splitting” the case open. This method is also referred to as piece pick or each-pick and is ideal for warehouses with large numbers of SKUs, i.e., tens of thousands, with low pick quantities.
Adjustable pick trays are combined with carton flow racks to present open cases to the pickers, facilitating product accessibility without interference from the shelf above.
Other Factors to Consider
When considering carton flow racks, you must consider various other factors beyond the type of item you store and the type of cases used. The most important being:
Bin type: The dimensions of your bin or tote are crucial to success. They should be appropriately aligned for depth and width. In addition to size, weight should also be considered, as varying load weights can affect balance, capacity, and flow. If your bins aren’t flat and have rollers or feet, you’ll also want to consider these for your carton flow rack system.
Flow angles: The flow angle is critical to ensuring smooth and efficient product movement. The incline should be steep enough to allow cartons to glide easily down the rollers but not so steep that they move too quickly or cause damage. Typically, a flow angle between 3 and 5 degrees works well, but the ideal slope depends on factors such as the weight, size, and material of the cartons.
Roller types: It's essential to consider the rollers or wheels used and whether braking mechanisms are needed to control the speed. There are two main types of rollers: full-width rollers and skatewheel rollers. Full-width rollers provide uniform support across the entire carton surface, making them ideal for handling products of various shapes and sizes. Skate wheel rollers, on the other hand, are better suited for lighter or uniformly sized cartons, offering more flexibility for curved or serpentine flow paths. Additionally, the material of the rollers, such as steel or plastic, affects durability and friction. Choosing the right roller type ensures smooth carton movement, reducing the risk of damage and improving picking efficiency.
The Final Word: Finding the Carton Flow System for You
With this ultimate carton flow guide, you now know more about the systems, what they’re best for, the factors to consider for yours, and their most common applications. So, does flow racking seem like a solution for your warehouse's bottlenecks and storage issues? Partner with storage, warehouse, and inventory experts, like BMH, to maximize overall efficiency and efficacy.
BMH is one of the fastest-growing companies in the material handling space, having grown 732% year over year in 2022. Our product lines and team of experts span from pallet racking and shelving to conveyor mezzanines, forklifts, and design services, enabling manufacturers, distributors, and logistics providers to not just survive but thrive.
Work with BMH by shopping our inventory now or getting in touch to learn more.
