EPCIS Implementers Need to Clean Up Their Data

By Ted Osinski

One hundred percent of first-time exchanges of EPCIS events between companies contained errors. If not corrected, such mistakes could jeopardize the promise of tracking and tracing.


> Osinski

July 13, 2009—A number of companies have begun using the EPC Information Service Validation Portal (EPCIS VP), a self-testing service available to RFID end users via the Internet. As usage grows, however, the EPCIS Validation Portal has detected a number of errors in the users’ EPCIS implementations. The quality of data collected by various RFID systems and stored in EPCIS databases is a concern. These mistakes, if not corrected, will affect the exchange of data between trading partners, and could jeopardize the promise of tracking and tracing. Fortunately, we are still in the early phases of RFID adoption, so such errors can be fixed at lower costs.

EPCglobal‘s EPCIS standard defines an EPCIS event, which contains information regarding a product tagged with an EPC Gen 2 passive RFID chip, as well as rules for exchanging event data. EPCIS VP analyzes a user’s EPCIS information and verifies an implementation’s adherence to the EPCIS specification, EPC tag data standards and EPCIS common business vocabulary (see How to Realize the Full Potential of EPCIS). In addition, the portal produces analytical reports, including an error summary and events analysis (for example, the number of read portals and their locations, business steps or business transactions used, the number of EPC keys read and the types of EPC keys employed). A company need not be an EPCglobal member to utilize the service, though members receive a 50 percent discount.

The idea behind EPCIS VP is that each company self-validate its own EPCIS data to ensure internal RFID applications create correct information for integration with a company’s enterprise resource planning (ERP) software, and for exchanges with trading partners. Every business in the supply chain, therefore, should make sure the EPCIS data created is valid and can be exchanged. This is especially important for retailers, who receive EPCIS data from many suppliers. Retailers should not be validating the data and resolving errors themselves—they should expect correct information from the onset. Likewise, the retailers should also send valid EPCIS data back to their suppliers.

Unfortunately, this is not presently the case. One hundred percent of first-time exchanges of EPCIS files between companies had errors. That does not mean each event recorded in the transmitted file was flawed. However, the same type of error was propagated across all events in the transmitted file.

The end result? The whole EPCIS event file is rejected by a receiving user, and a debugging process begins. As more and more companies validate their data, EPCIS VP provides invaluable information and statistics regarding issues discovered with current implementations. EPCglobal and MET Laboratories, which co-developed the service, will not reveal the identities of the companies that have signed up thus far. However, the errors and common problems experienced by those firms must be brought up, so that a broader community can learn about them and take preventive action.

Major Causes of Errors

EPCIS errors are typically generated either by internal RFID applications, or by trading partners sending or receiving EPCIS data. There are two main causes: (1) Companies developed (or purchased) EPCIS applications based on a draft EPCIS specification, and the ratified EPCIS standard is significantly different (the XML schema has changed, for instance). (2) Companies are using non-certified RFID hardware and software, thereby resulting in RFID applications that generate invalid EPC keys or other types of EPCIS data.

The following types of errors are typical of those experienced by early users of the EPCIS VP service. In these examples, all users were fast-moving consumer goods (FMCG) companies.

EPCIS events fail XML validation: This type of error is typical for applications that implemented early EPCIS specifications. The document header is coded incorrectly; values are invalid for date or time (the time zone specifier is missing). Nearly all implementations got this wrong!

EPC: Uniform Resource Identifiers (URI) are in violation of the tag data standard for read point, bizLocation or bizTransaction; EPCs are invalid.

Core Business Vocabulary (CBV): Uniform Resource Names (URNs) are invalid for bizStep, disposition, read points or bizLocation; values are invalid for locations or bizTransaction; values are missing. (Technically, the latter is not an error since most of CBV is optional, though it does call into question the data’s usefulness. This will be rectified in the new CBV specification.)

Extension: There is an invalid use of elements reserved for future use, or the structure is invalid.

All of the above problems have been discovered at the stage when companies have begun exchanging production EPCIS events with each other. The costs of fixing the problems at this point in time are exponentially higher then addressing them before going to production. It also leads to pointing fingers. If problems go unnoticed or stay unresolved for too long, they will undermine the premise that EPCIS can be a solution for product recalls, electronic pedigrees or track-and-trace applications. It is thus imperative that companies throughout the supply chain realize it’s in their best interest to validate their EPCIS data. Wal-mart and Sam’s Club have even stated they will mandate that suppliers validate their data prior to sending it to them.

Ted Osinski is the director of RFID programs at MET Laboratories, which provides testing certification services for a range of standards, including RFID.