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Racking 101

Selecting the right storage module for your product can make a difference with space requirements and the productivity of your operations. Find out how to determine which type of racking system is the best choice based on your storage needs.

Developing an accurate inventory profile of the product is essential in order to select the appropriate storage module. This profile should include the total number of pallets as well as the pallet sizes by item or SKU. Your system should be able to generate a “Stock Status Report” which records the inventory levels for every item in your warehouse.

The following list describes some “rules of thumb” when allocating storage modules to products. For example, if a certain SKU has 1 – 5 pallets of product in the warehouse at a given time, Standard Selective Racking is recommended as the storage module. This list covers the most popular storage modules in use.

• If 1-5 average pallets/SKU use Standard Selective Racking
• If 6-8 average pallets/SKU use 2 Deep Pushback or 2 Deep Flow Rack
• If 8-10 average pallets/SKU use 3 Deep Pushback or 3 Deep Flow Rack
• If 10-15 average pallets/SKU use 4 Deep Pushback or 4 Deep Flow Rack
• If 15-20 average pallets/SKU use 4 Deep Pushback or 5 Deep Flow Rack
  

Drive-In racking is only recommended when there are over 20 pallets/SKU. Depending on the number of pallets, Drive-In racking may be anywhere from 2 – 6 pallets deep.


Selective Pallet Rack
This type of racking system allows for the most efficient selection and movement of product. Typically, the aisles in between the racks are 10’ – 12’. While this provides for maximum accessibility and less congestion (as two forklift trucks can pass one another), it takes up more space in the warehouse than other storage modules. Thus, the density of this storage module is the lowest. This type of rack system is useful for faster than average moving product.

Pushback Racking
Pushback racking is a higher density storage module for products that have greater than 5 pallets/SKU in inventory. The trade-off is lower selectivity for higher density. Pushback systems follow the ‘last in, first out’ inventory methodology. Thus, it is not the best storage medium for product rotation, especially if the product is date sensitive.

Flow Rack
Flow rack supports ‘first in, first out’ inventory. This is an excellent choice when product rotation is important. The system operates on gravity. The forklift operator feeds the pallet from behind the system and the pallets ‘flow’ to the other end. Thus, one end of the system is for loading and the other for picking. This helps reduce forklift truck congestion. This storage module is also a higher density, meaning that less square footage is required in the warehouse to store more pallets than selective racking.

Drive-In Racking
Drive-In racking offers the highest density storage. It is a good choice when space is at a premium, such as refrigerated or freezer applications, however it must not be overused as if many SKUs are stored in one bay accessibility will become an issue. This will also negatively affect productivity.