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The ABCs of EPCs

Over the last 15 years, universal product codes (UPCs) used with bar codes have become the dominant product-tracking standard across all industries.

Created by U.S. manufacturers to gain an advantage over cheaper offshore manufacturing labor, UPCs have improved companies’ ability to track goods across multiple trading partners, reduce labor costs and speed up product replenishment.

But now, the next great leap in the evolution of product tracking has emerged—electronic product codes (EPCs.) Developed for use with radio frequency identification (RFID) technology, EPC refers to a 96-bit numerical schema that provides multiple levels of product identification. EPC is administered by EPCglobal (—a consensus-based, not-for-profit standards organization—and has gained the support of numerous leading companies and organizations. Wal-Mart Stores Inc., for example, is specifying use of EPCs for its widely publicized initiative mandating RFID tagging by its suppliers.

There are currently two main types of EPCs—Global Trade Identifiers (GTINs) and Serialized Shipping Container Codes (SSCCs). Most common, and the focus of this article, are Global Trade Identifiers. GTINs supply identification for same-Stock Keeping Unit (SKU) groupings. With the retail and consumer goods industries spearheading EPC adoption efforts, the need for identifying groupings of like items was paramount. A second type of EPC has emerged in order to expand adoption throughout industry supply chains. Serialized Shipping Container Codes allow companies to account for mixed SKU pallets and cases.

Information is read in a string of bits. Regardless of the type of EPC, the first eight bits are called the Header. The Header determines how the remaining data on the tag is read based the length, organization and structure of the numbers.

For the GTIN type, the next four bits, the Object Identifier, tell the reader if the tag being read is on a container, pallet case, carton or item. By making this distinction, a system can know exactly what is being received into inventory or shipped to a customer. Currently, UPCs do not have this capability. Instead, the same number is used whether an object is an item, case or pallet, so there is no way to know the exact number of goods being received, without counting or scanning every physical object. With an Object Identifier in place, companies can program readers to read only pallets or only cases. Not only does this provide more accurate information, but it also prevents readers from being bogged down with unnecessary data.

The third and fourth sections of the EPC work together. The third section, the Partition, explains how to read the fourth part, which is the actual GTIN. The GTIN contains a company prefix, which identifies the company shipping the product, as well as an item reference, which tells what the item is. The Partition serves to tell the reader where the company prefix ends and the item reference number begins.

Perhaps the most beneficial piece of information an EPC provides is the fifth and final section, the Serial Number. The Serial Number is what defines a unique instance of a specific product. Unlike UPCs, which just tell readers that this is a certain “type” of item, Serial Numbers indicate exactly which particular item it is. This eliminates the need for human interaction to determine the exact number of unique products.

EPC was developed by the Auto-ID Center, a partnership of global companies and research universities that finished its EPC work last October. EPC has now been turned over for administration and further development to EPCglobal, a joint venture between EAN International and the Uniform Code Council, the two main bodies that oversee international bar code standards.

EPCglobal includes participation by end-users, software providers and hardware vendors. Together they have worked to establish new, open, global standards for real-time, automatic identification of items anywhere in the supply chain. The group is also working on the standardization of an EPC data catalogue that companies can use to store and exchange data with trading partners. The final standards and implementation is still in process.

With EPCs, RFID and other Auto-ID technologies can be supported—revolutionizing the supply chain as it exists today. Labor costs will decrease, accuracy and efficiency will increase and the fulfillment process will be streamlined.

Greg Gilbert,, is RFID strategist for Manhattan Associates, a provider of supply chain execution solutions.

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