A push back pallet rack system can add pallet positions by storing loads several deep behind a working aisle. It suits operations that handle several pallets of the same product or batch and can accept last-in, first-out access within each lane. The trade-off is reduced pallet selectivity: a load deeper in the lane cannot be picked without first removing the pallets in front of it. Before choosing push back racking, compare its usable capacity with your SKU mix, stock rotation rules, forklift movements and replenishment pattern. A denser layout is only an improvement if staff can still store and retrieve goods at the pace the operation needs.
Push back racking uses inclined rails and carts to hold pallet loads in a storage lane. A forklift places a pallet on the front cart. To load another pallet, the operator pushes the first load farther into the lane, making room for the next cart and pallet near the aisle. The same process continues as the lane fills.
When the front pallet is removed, the carts and remaining pallets move forward under gravity. The next load becomes available at the aisle. The forklift works from the aisle rather than driving into the storage lane, but it must handle the system as designed and avoid striking the rack or carts.
Each lane is therefore a sequence, not a set of individually accessible pallet positions. The pallet nearest the aisle is the next one available. Lane depth and the number of storage levels vary by design, so the usable capacity and operating requirements need to be assessed for the particular layout rather than assumed from a general description.
The system is most useful when you have enough stock of a product to fill several positions in a lane, and the pallets can be retrieved in the order they become available. It can work well for reserve storage or replenishment stock where the picking process does not require access to every pallet at once.
It is less suitable when a wide range of SKUs each occupy only one or two pallet positions. Each additional SKU may need its own lane, which can leave space unused or force the operation to split stock across lanes. Splitting a product across lanes can be managed, but it requires clear location control and disciplined replenishment.
Check how the system interacts with inventory rotation. Push back lanes are last-in, first-out: the most recently loaded pallet is typically the first retrieved. That can be acceptable for products without strict date sequencing, or for stock managed in separate, identifiable batches. It may be a poor fit where the oldest pallet must always be picked first. In that case, a first-in, first-out arrangement or a different storage method may better support the process.
Consider more than average stock levels. A product that usually occupies several positions may be difficult to manage in push back lanes if demand changes sharply, pallets arrive irregularly, or individual lots need separate access. Review the highest and lowest stock levels, the number of active SKUs, batch rules and expected replenishment frequency before assigning products to lanes.
Storage density and selectivity often pull in different directions. A system that holds more pallets in a given area may make each pallet harder to reach. The comparison below focuses on the operating differences; actual capacity depends on the building, layout, equipment and system design.
| System | Access pattern | Rotation | Useful when | Main trade-off |
|---|---|---|---|---|
| Selective pallet racking | Each pallet position is reached from an aisle | Flexible; pallets can be selected individually | There are many SKUs or frequent, varied picks | Aisles take floor space and limit storage density |
| Push back racking | Loads are stored and retrieved from the same aisle | Last in, first out within a lane | Several pallets of the same SKU or batch move together | Deeper pallets are blocked by loads in front |
| Pallet flow racking | Loading and retrieval are generally from opposite ends | First in, first out | Stock needs a controlled flow-through sequence | Requires access and workflow at both ends |
| Drive-in racking | Forklifts enter the storage lane to place and retrieve loads | Typically last in, first out | Large quantities of similar stock can share a lane | Truck movement within the lane calls for careful operating control |
Selective racking is often the clearest choice when each SKU needs direct access or order picking involves many different products. Push back can reduce the number of aisles required for a given stock profile, but its lane-by-lane access needs to fit the picking sequence. Pallet flow is worth comparing when stock rotation matters more than accessing the lane from a single face. Drive-in racking may offer another dense option, but its forklift operating method differs substantially from push back.
Use actual inventory and movement data to test the proposed layout. A simple pallet-position total can make a dense system look attractive while hiding the number of lanes needed, the stock that will not fit a full lane, or the extra handling required to reach a particular batch.
For example, a product with steady demand and several pallets in stock may be a practical candidate for a dedicated push back lane. A low-volume SKU that occupies one pallet position but needs immediate access may be better placed in selective racking. This kind of mixed layout can preserve direct access for selected goods without giving up density everywhere.
Pallet dimensions, load condition and weight affect how loads sit and move on the carts. Confirm that the proposed equipment is designed for the pallets and loads you actually store, including any variation in pallet quality or product packaging. Have the supplier or designer check the handling equipment, load placement and clearances together rather than treating the rack as a separate purchase.
Forklift operators also need to understand how to load and retrieve from the system. The method may differ from placing pallets on ordinary beams, and careless contact can damage rack components or carts. Include operating instructions and training for the specific installation in the implementation plan.
Give each lane a clear product or batch assignment, and make that assignment visible in the warehouse management process and at the rack. If one SKU occupies multiple lanes, define how staff choose between them. Otherwise, stock can be replenished into one lane while the picking process draws from another, making rotation and stock counts harder to manage.
Also decide how workers will handle an exception, such as a damaged pallet or a batch that must be accessed before the load in front of it. The answer may involve relocating the blocking pallets, using another storage location or holding stock for inspection. Set out the process before the layout is in use so the exception does not become an improvised forklift manoeuvre.
Have a competent rack designer or supplier assess the intended loads, layout and operating conditions. Confirm the permitted configuration and load information for the installed system, and establish how the rack, rails and carts will be inspected and how damage will be reported. Do not alter components or continue using a visibly damaged area without following the appropriate assessment and repair process.
Check building interfaces before committing to the design, including floor conditions, column locations, fire protection and sprinkler clearances. For a New Zealand warehouse, ask the designer to address the applicable local building and seismic requirements for the facility. These checks can affect the layout and specification, so they belong in early planning rather than after equipment has been ordered.
Compare the installed system with alternatives using the same assumptions about usable capacity and warehouse activity. The purchase and installation are only part of the decision. Include any design and facility work, equipment changes, operator training, ongoing inspections and the labour involved in putting away and retrieving stock.
Then consider the cost of reduced selectivity. If staff often need a pallet that sits behind another load, the extra movements may offset the benefit of storing more pallets in less floor area. Conversely, when products are handled in lane-sized quantities, fewer aisle movements or a more compact storage footprint may support the operation. The result depends on the actual order and replenishment pattern; a generic cost-per-position comparison will not show it.
Ask for a layout proposal that explains its assumptions: which products are assigned to each lane, what stock levels it is designed around, how access works, and what equipment is required. Compare that proposal with a selective-rack or flow-rack alternative where the inventory profile makes those systems plausible.
If several answers are uncertain, test the design with representative inventory and order scenarios before committing. Push back racking is a strong candidate when lane-level access matches the way stock moves. Where the operation depends on individual pallet selection or strict first-in, first-out rotation, a denser layout may create more work than it saves.
It is generally a last-in, first-out system within each lane. The most recently loaded pallet is at the front and is normally retrieved first, so the system may not suit stock that must be picked in arrival order.
They can be physically placed in a lane, but doing so can make access and inventory control difficult because loads are retrieved in sequence. Assigning a lane to one SKU or a clearly controlled batch is usually easier to manage.
No. The pallets in front must be removed before a deeper load becomes accessible. If that extra handling is frequent, consider a more selective storage arrangement or revise the product and lane assignments.
Push back systems generally load and retrieve from the same aisle and operate LIFO. Pallet flow systems typically load from one end and retrieve from the other, supporting FIFO when the layout and stock process are designed for that flow.
It can increase storage density by reducing the need for aisles between individual pallet positions, but the gain depends on the building, stock profile, lane use and equipment. Compare the positions that can be used in practice, including partly filled lanes and access needs, rather than relying only on a nominal capacity figure.
A push back pallet rack system is most effective when its lane-based, last-in, first-out access fits the inventory and handling routine. Base the decision on real SKU volumes, pallet access needs, forklift movements and facility constraints. If those checks show that the added density will not create frequent extra handling, push back racking may be a good fit; if they do, compare it with a more selective option before finalising the layout.
