May 23, 2007This article was originally published by RFID Update.
May 23, 2007—It's been more than 14 months since Pfizer went live with its pilot to tag all of Viagra trade items with radio frequency identification (RFID) technology for the U.S. market. At the time of this writing, Viagra is one of only two major pharmaceutical products whose entire product line is tagged for the United States. Millions of RFID-enabled units illustrate the feasibility of mass serialization using RFID tags with bar codes. High-frequency (HF) and 2-D bar code technology selections demonstrate good performance superior to ultrahigh frequency (UHF) Gen1 and linear bar code technology selections.
This article analyzes the real, unfiltered performance data of bar code and RFID technologies that have been selected and been in use on Pfizer's production line over the past 14 months.
The Pilot Program
The Viagra RFID pilot was conceived in 2004 and sought to tag every sales unit for the United States by the end of 2005. By December 2005, the first RFID-enabled items were shipping to U.S. customers. The first customer authentications occurred in January 2006. While the original pilot end date has passed, Pfizer will continue to tag Viagra to learn more internally as well as externally. At the 2006 Healthcare Distribution Management Association (HDMA) conference in Arizona, Pfizer announced that it would not cease tagging Viagra at the end of the one-year period in an effort to demonstrate an ongoing commitment to the safety and security of the pharmaceutical supply chain. Pfizer has taken very seriously the effects that new technologies have on patient safety. Continuing to tag Viagra beyond the original pilot evaluation period is the right decision for Pfizer's supply-chain partners, regulators, and, most importantly, patients.
Technology Choices
Pfizer surprised quite a few professionals in the RFID community when it chose to split frequencies by using UHF tags on cases and pallets and by using HF tags for the item level. We had many reasons for making this choice, including our real-world experience with UHF tags from a variety of vendors for existing deployments. Most influential were the comments and guidance from frequency-unbiased integrators and technologists who had previously worked with both technologies. Their independent experiences indicated that HF was the better choice for the challenges Pfizer and Pfizer's customers had to overcome to enable successful reads of RFID on bottles of Viagra. The results of the Viagra pilot have further added to the success stories of the installed base of HF.
Additional factors were:
- An operational history of HF in production-line and item-level applications.
- An ability to accurately read and write a single HF tag in a production-line environment without major equipment alterations or shielding or without compromising line speeds.
- Proven laboratory test results demonstrating Six Sigma shipping-case aggregated read rates, without reading other tags near or outside the case.
- A wide variety of available HF hardware choices.
- Tag form factors conducive to a wide range of very small pharmaceutical package types.
- Universal applicability of the HF frequency throughout the world.
- Trading partner feedback.
We understood there was a desire by some to have one frequency across all packaging levels. However, there appeared to be disadvantages to having a universal frequency as well as a concern that it would fail to meet performance criteria throughout the entire supply chain. A typical pharmaceutical pallet of product can contain more than 5,000 individual saleable units in various combinations of packaging, including those with a high level of metal and liquid content. By using both frequencies and their respective protocols, we leverage their respective strengths and weaknesses as we strive for speed, accuracy, and reliability.
The packaging line process can be described as follows:
- HF RFID tags are converted into the preprinted Viagra label.
- 100% inspected converted tags are shipped to the production line.
- Tags are tested on the line, prior to application.
- Tags are encoded with an electronic product code (EPC) at existing line rates.
- Labels are then printed with a redundant EPC 2D bar code.
- Inspection or check of the encoding and printing is undertaken at multiple points; failure mode is recorded.
- Bottles are aggregated to a case.
- UHF case tag labels are encoded, printed with a bar code, and applied.
- Inspection or check of the bar code, UHF case tag, and aggregation with the HF tags is performed; failure mode is recorded.
- Only 100% readable product is shipped to Pfizer U.S. Logistics Centers.
Performance Data
A regular topic of discussion is "is it really working?" In presenting this data, which is listed in Table I, it is important to stress two points:
- The data presented are based on several million units of actual product on the Viagra production line.
- The results are compiled from data collected over a period greater than 1 year and are completely unfiltered, except where noted.
| QC Process Steps | QC Failure Rate | Read Yield |
| Shipment from Converter | 100% | |
| Item Rejections because of HF RFID (all causes) | 5 in 1,000 | 99.5% |
| Item Rejections because of 2D bar code | 3 in 1,000 | 99.7% |
| Case Rejections because of HF item aggregation* | 4 in 10,000* | 99.9%* |
| Case Rejections because of UHF Gen1 tag** | 3 in 100** | 97%** |
| Case Rejections because of linear bar code | 2 in 100 | 98% |
Table I. Performance data from Pfizer's use of RFID for Viagra.
* Based on 48 HF reads/case.
** Duplicate-code issues and void label failure rates omitted.
Analysis
The following points can be made:
- It's important to stress that the read-failure rates are all part of the on-line QC process, which allows Pfizer to deliver 100%-readable tags from the packaging line.
- Expected failure rates from our tag supplier and label converter was 5 in 1,000 failures on inspection off the roll; actual failure rate is 4 in 1,000.
- HF and 2D bar code failure rates are not significant in comparison to the failure rates for UHF and linear bar code.
- Errors on the production line that could "break" the system have not occurred or have been prevented given the nature of the frequency selections.
- All data are unfiltered except for the UHF case rejections.
Conclusion
The results of the Viagra pilot have further added to the success stories of the installed base of HF. Our data indicate that an HF-frequency approach is desirable for item-level applications combined with a 2D redundant EPC bar code. Unfortunately, it also calls into question the selection of UHF and linear bar codes at the shipping-case level with failure rates being far higher than expected.
Pfizer will move to UHF Gen2 for case and pallet tagging of Viagra in 2007 and expects to see improvements in UHF encode and read performance. A change to the redundant linear EPC bar code on the case and the UHF tag placement are also under consideration in 2007. Our data indicate a one-size-fits-all approach on frequency remains unproven, underdeveloped, and too immature for the pharmaceutical supply chain. As an end user however, Pfizer will continue to evaluate all technologies to determine best fit for purpose as we proceed with future patient safety initiatives.
