Sep 27, 2005This article was originally published by RFID Update.
September 27, 2005—Much has been written discussing the difficulties of implementing EPC passive RFID tags in the supply chain, so this article will attempt to present a viable new use for these tags in an old and seemingly forgotten application.
One of the difficulties of almost all passive RFID technologies is in the use of stationary readers where tags pass through portals mounted to an assortment of materials or objects in a wide variety of orientations and buried to random depths by other tagged objects. EPC passive UHF tags are especially vulnerable to reliability issues in this type of activity. As a solution, working with mobile readers enables the reader to move relative to the tag, thus removing issues of orientation, dead spots, and even range reductions due to incompatible materials. While this may not be practical in the supply chain applications that are so popular in mainstream RFID at the moment, it certainly makes these tags a viable and cost-effective candidate for other applications compatible with the RFID technology space.
One such application is Fixed Asset Management. Passive UHF RFID technology is optimized for this application as long as anti-theft requirements are not part of the requirement.
A recent study performed by the IT Department for the District of Columbia Water and Sewer Authority (DCWASA) evaluated the ROI of such an implementation for replacement of a manual process of managing IT assets. DCWASA manages thousands of information technology assets which the IT department maintains and upgrades in accordance with a strategic assessment of overall return on investment (ROI) for the enterprise.
Mr. Omer Siddiqui, the IT Operations Manager for DCWASA, stated in an interview, "Having clear visibility over the distribution, accountability and utilization of our IT assets is necessary information for us to accurately determine the ROI of our existing strategic IT objectives as well as for planning future strategic directions."
In this particular case study, DCWASA was currently managing all IT assets in a mostly manual process. The inefficiencies of such manual processes are obvious, allowing a physical reconciliation only once or twice a year. Worse yet, there are many opportunities for human error to enter the system during the interim periods. The leap from a manual process of taking physical inventories and managing asset movements to an automated data collection methodology using EPC passive UHF tags was dramatic. In addition, the technology automated the interim tracking processes, providing a dramatic improvement in the accuracy of the information flow.
IPAQ units using WJ Communications MPR5000 readers running Microsoft Pocket PC were chosen as the mobile reader platform at very low cost and compact size. All classes of tags were tested and were programmed through a custom procedure implemented in Visual C++.
Tag performance was fairly consistent from Class 0+ to the various manufacturers of Class 1 tags, as mounted on the IT assets. But because some of the Class 0+ manufacturer tags had yield and encoding problems, Class 1 tags were chosen for this application. Yields were greater than 99% on the Class 1 tags, and programming was a breeze.
A simple standard operating procedure was implemented that mostly defined where the tags should be mounted. Using common sense, assets with metal or FCC coatings needed to be tagged in places with as much space as possible between the tags and the metal base or coating. Laptops presented a difficult challenge in this area with a very limited set of locations where tags would adequately work.
Carefully placing tags in this way, the read range from clear air- to asset-mounted tags on PCs and monitors dropped by 70% or more. Even with these performance reductions, the average range ended up significantly farther than what could be achieved by way of existing HF tags operating at 13.56Mhz. "...comparing HF, bar code and EPC UHF tags relative to cost/performance gains and data capture efficiency, the clear winner was UHF," Mr. Siddiqui noted.
Mr. Siddiqui's observations are clearly supported by the results of this study. HF tags are generally more expensive than UHF tags at the current time and suffer from a lack of mobility solutions in the readers where the range is functional in an application like this. Bar codes are a lower cost option for fixed asset management, however this study found the price difference to be somewhat inconsequential. Capturing bar code data still requires fairly tight orientation guidelines and direct line-of-sight to the bar code label by the reader. The time differential on a per asset basis was significant when compared to passing the MPR5000 reader within one to three feet of the asset at a relatively imprecise orientation angle at fairly fast speeds. Furthermore, Mr. Siddiqui observed, "The process had very little, if any, impact on the person working with those assets at the time of measurement. Our old manual method, or the bar code method, would generally require the person to leave his or her work area temporarily. This not only more than offsets the added cost of using EPC RFID labels, but the efficiencies gained enabled the monitoring and taking of physical inventories more frequently than twice each year."
DCWASA also experiences a lot of IT asset movement throughout the year, making reconciliation a large proportion of the work in between physical inventories. Mr. Siddiqui commented further, "Additional applications installed on the handheld units have significantly improved the ease with which we can keep our database up to date relative to asset movement and new asset deployments. The 100% ROI will be realized in the very first physical inventory using the new system. With all the assets tagged now, the reconciliation time will become less and less of a time burden since the database will be kept up to date on a real-time basis."
Additional testing on furnishings and other assets is underway, and Mr. Siddiqui looks forward to further implementations of the technology throughout the plant: "This technology can be easily leveraged, making my initial investment work in a myriad of other productivity enhancing applications around the plant. When implemented properly and creatively, this technology can have a dramatic impact on operations relative to the old ways of doing things."
DCWASA is headquartered in southwest Washington, DC, and, through the use of advanced technologies, has been very successful at improving productivity issues as they relate to servicing its large and diverse customer base.
