Modern distribution centers do not stick with one storage solution throughout their entire operation, as it is likely that in today's global marketplace where the customer is expecting a high level of service and a speedy turnaround, the operation will have a diverse variety of products that each need handling in a specific manner. This in turn means a specific storage system. A proper DC design does not consist of a simple back to back pallet racking system where the business uses it as a means to everything due to its cheap price, but rather a matrix of different systems each tailored to the specific need of the product SKU.
A product analysis should be carried out to determine the types of products as well as their picking routines and how they are handled. Are they handled by piece? By pallet? What is the volume picked and how often? Do you have shifts? What are the warehouse dimensions and available storage space in relation to the order picking preparation and loading/unloading areas? All of this should determine the type of storage system, its configuration as well as the required spaces needed for handling, through traffic and order processing. For example products that come in large pallet quantities with few SKU's should consider a drive in system, flow rack or even a satellite channel storage. Large variety of SKU's in lower volume start with a back to back pallet storage to a VNA or mobile rack system. Which sub system again depends on a more detailed analysis of your daily operations and your warehouse environment.
On the other end of the spectrum you may also do piece picking meaning that you may want to allocate the first level of your pallet rack for carton storage, combine a carton live storage system with pallet racking or indeed have a shelving or multi-tier system in a separate area. Other special size products such as long items can go onto cantilever racks (also available on mobile bases). The possibilities are endless.
Do not be afraid to consider various systems in your DC layout. Visit several blue-chip companies to see how they operate and get talking to their logistics managers; find out what works well for them and what they consider as improvements to their operations. Remember that spending more on a mix of systems will yield high operational efficiencies, decrease errors and increase profitability for your business.
Last but not least it is important to budget for a good warehouse management system (WMS) in order to assist with the flow of goods in the most efficient manner possible. Technologies such as RFID can enhance this process further.