A New EPC on the Block

By Ken Traub

GS1 has developed an RFID standard for identifying automotive components and parts.

Automotive manufacturers have been using RFID to manage operations in closed-loop applications, but the industry has never had a standard way to track materials and goods in the open-loop supply chain. Until now. GS1 has just published Version 1.7 of the Electronic Product Code Tag Data Standard, which will enable auto manufacturers to receive RFID-tagged components and parts from their various suppliers.

The consumer industry has been using EPCs to uniquely identify items in manufacturer-to-retailer supply chains. But RFID-tagging auto components and parts differs from tagging consumer goods because of the way numbers are assigned. EPCs for products have three parts: a header that identifies the EPC format, a product identifier and a unique serial number. In the case of a consumer product, the product identifier—typically, a Global Trade Item Number (GTIN)—is chosen by the product's manufacturer. The manufacturer assigns a different GTIN for each product, then encodes the EPC header, GTIN and unique serial number into the RFID tag it affixes to each instance of the product.

In the auto industry, the carmaker assigns the part number (equivalent to a product number) for each auto component or part. But the supplier must encode and apply the RFID tag so the part can be tracked on its way to the carmaker. This creates a challenge, since each carmaker has its own series of part numbers. Two carmakers, for example, could use number 1234 to identify different parts from the same supplier.

GS1 solved this problem by introducing a new type of EPC called the Component/Part Identifier (CPI). The CPI combines a unique GS1 Company Prefix issued to each carmaker with the carmaker's part number, to create an overall part number that is globally unique. If two carmakers both use part number 1234, each CPI will be unique because its company prefix is different.

In software terms, the CPI introduces two new EPC headers. One header defines a 96-bit CPI format that can hold a short numeric part number; the other header defines an encoding for larger tags that can accommodate an alphanumeric part number.

Carmakers that implement CPI must obtain a GS1 Company Prefix and communicate it with their part numbers to their suppliers. Both carmakers and suppliers must ensure that their RFID middleware or other software knows how to encode and decode the CPI structure in accordance with the standard. Not all RFID hardware and software products will handle CPI out of the box, so carmakers and suppliers will need to familiarize themselves with the encoding and decoding procedures, and either implement them themselves or ask their vendors to do so. I've posted a free interactive encoder/decoder at www.kentraub.com/aidc, which you can use to get started.

Ken Traub is the founder of Ken Traub Consulting, a Mass.-based firm providing services to companies that rely on advanced software technology to run their businesses. Send your software questions to swsavvy@kentraub.com.