Supply chain mandates for use of radio frequency identification device (RFID) technologies put control engineers in a position of strength, since engineers have long seen RFID more as a benefit than a cost. Two approaches continue to be underway in many facilities.

One is the “slap and ship” concept, where the lowest-cost RFID tags (transponders) are applied to comply with requirements from Wal-Mart, Target, U.S. Department of Defense, and others, and added to the cost of doing business with those customers. Such RFID tags often are applied as materials are packaged, scanned, and information fed into supply chain logistics software. These warehousing or shipping functions are often, though not always, led by IT personnel. Manufacturers may not have a plan for extracting benefits, other than to please the customer.

Within the facility, RFID is being applied from the design phase, through manufacturing, assembly, inventory, and shipping, with tags attached to various components, skids, and even related tools and persons. Costs also have decreased for RFID tags traditionally used in manufacturing (as opposed to shipping), and lifecycle costs for these can be quantified, lowering cost per use. These manufacturing-rooted efforts are extending into the warehouse and may be led by plant-floor, control engineering personnel.

The mindset going into an RFID project can govern choice of vendors, consultants, system integrators, data use, and budgets. Despite recent RFID furor, RFID transponders and readers have been used in manufacturing more than 20 years (and were first applied in WWII for identification of Allied airplanes.) Trends include:

• Greater use of integration services and automation system integrators for RFID;
• Universal readers that can read tags of varied designs, of multiple frequencies, and from different manufacturers;
• Tighter integration of RFID for real-time asset tracking (linking tools, materials, and processes) connection to control systems to improve throughput and speed work in process;
• Better understanding of active and passive RFID tags and appropriate applications for each in manufacturing through shipping;
• Wider use of standards and related certifications, lower cost per point and increasing industry knowledge through wider use; and
• Lower-cost, rugged tags; more security.

In offering technologies to the market, some RFID vendors tend to focus more on the IT, data-oriented, open-loop, retail side of the supply chain. Others have better understanding of manufacturing applications, where the tags (generally larger and more expensive) can serve as a traveling data repository, carrying information about the tagged item through stages of production, more as a smart sensor in a closed-loop process. Alex Stuebler, business manager, RFID, Siemens Energy & Automation, says Siemens does both and can serve the diverse global market, which could be buying billions of tags and tens of thousands of readers within the next 12 months.

With that kind of market pull, RFID products, services, hardware, and software are being applied from the top down, the bottom up, and from the middle in both directions. Stuebler suggests the full structure extends, much like the familiar software or networking diagram, from sensors on the plant floor through the enterprise and connected supply chain. From highest to lowest level, Stuebler says, RFID touches:

• Global integration of EPC (EPCglobal’s Electronic Product Code) and databases;
• Enterprise resource planning (ERP) with supply chain management middleware;
• Control level with RFID devices and data management;
• Data acquisition; and
• Sensor level. Tags here can give (read only) or give and receive (read and write) information, don’t have to be line of sight, and generally are more reliable than bar codes for information exchange in many applications.

Most RFID hardware uncertainties have been answered in recent years, suggests Mike Wills, vice president, Intermec. “The long-term value, return on investment, and total cost of ownership that an RFID system produces are all heavily dependent on the initial process design and implementation decisions,” Wills says.

Even with available standards, Wills suggests, RFID isn’t close to plug and play. He advises paying attention to system infrastructure planning; determining the degree of communication and integration required for host systems; supporting current processes or designing new ones; developing supportable criteria for systems performance success; applying the most effective readers, antennas, tags, and standards; and making sure it all works as intended as quickly as possible.

Engaging a professional services provider early increases the chances for success and helps avoid implementation delays that can undermine return on investment, Wills says. While greater familiarity means companies are more likely to bring training, maintenance, and support in-house, they will continue to outsource integration and installation tasks, Wills contends, citing the October 2006 “RFID Professional Services” market research report from Venture Development Corp.

Trade group Aim Global (Association for Automatic Identification and Mobility) says RFID tags can be read very fast in challenging circumstances, usually responding in under 100 milliseconds. Active RFID read and write capabilities offer advantages for interactive applications (work-in-process or maintenance tracking).

Low-frequency (30-500 kHz) systems, says Aim Global, have short reading ranges and lower system costs (for security access, asset tracking, and animal identification). High-frequency (850-950 MHz and 2.4-2.5 GHz) systems offers long read ranges (>90 ft) and high reading speeds (for railroad car tracking and automated toll collection). High-frequency systems have higher performance and higher costs, Aim Global adds.

Standards (de facto and formal) have helped accelerate adoption, says another industry organization, EPCglobal. As of December 2006, more than 1,000 companies globally, in 12 major industries and 51 industry segments, are said to be using EPCglobal Electronic Product Code RFID technology. Last year, EPCglobal certified 45 RFID hardware and software products and ratified seven global standards, including the International Organization for Standardization UHF Gen 2 Air Interface protocol (ISO 18000-6 part C. Working groups formed to extend the logic and technology the ultra-high frequency standard into the high frequency band and develop security extensions for item-level tagging.

“At Procter & Gamble, EPC/RFID provides us with the means to see our products move from the point of production to the point of sale,” said Dick Cantwell, EPC team leader, Procter & Gamble and chairman, EPCglobal Board of Governors. RFID “allows us to watch every step between those two points, which results in a more accurate, safer, and more secure supply chain,” Cantwell says.

RFID discussions need to fit the RFID system to application needs, says Gabi Daniely, AeroScout vice president of product strategy. Within industrial manufacturing, Daniely says, active RFID tags (battery-powered, rather than passive, unpowered tags) can easily track assets (machinery, toolkits, and work-in-progress inventory). Real-time asset tracking can integrate information into control systems, driving business intelligence for increased efficiency and throughput.

Taking advantage of pre-existing network infrastructure, such as RFID reader Wi-Fi (IEEE 802.11b) access points, accelerates return on capital. One infrastructure can deliver data, voice, and RFID services to make them “easier, less disruptive, and less expensive to implement,” Daniely says. Batteries boost communications to more than 90 ft, even in metal-filled environments, without use of a handheld “scanned” reader. “Tags also can include sensors and be programmed to proactively send alerts” at a certain temperature, Daniely says.

Boeing uses AeroScout’s Wi-Fi-based Active RFID to speed final aircraft assembly. Previously, engineers spent time locating needed parts and tools in the nearly 100-acre plant. High-value airplane components and equipment now carry tags. Using the facility’s Cisco wireless network, AeroScout’s MobileView software enables engineers to speed assembly.