How to Improve ROI with RFID
Industrial production line use of radio frequency identification (RFID) has become increasingly popular, and the technology has become a hot-button topic. Why? Technology enhancements have advanced RFID far beyond its barcode counterparts—and gotten attention for return on investment (ROI) opportunities.
Mark DiSera, Turck
Industrial production line use of radio frequency identification (RFID) has become increasingly popular, and the technology has become a hot-button topic. Why? Technology enhancements have advanced RFID far beyond its barcode counterparts—and gotten attention for return on investment (ROI) opportunities. While some companies may have argued that they could not afford to implement RFID into their operations, many now argue they cannot afford not to. Knowing the basics of how and when RFID can improve ROI on the plant floor is central to understanding its relevance in your operation.
Basics of today's RFID
RFID was initially developed as a method for remotely gathering data through tags or transceivers, either attached to or embedded in the object from which data must be obtained. These tags employ internal circuitry and antennas to emit a radio frequency wave that is secured and analyzed by an RFID reader, and the system is often used for work-in-progress (WIP) in the industrial realm—tracking materials throughout the manufacturing process.
With its compact electronic design, RFID tags can come in virtually any housing style—from extremely small, embeddable devices to flat labels or stickers. In the industrial realm, RFID is often implemented within form factors that can be easily integrated into existing systems. For instance, manufacturers integrate RFID into sensor housings, because plant engineers are already aware of how sensors are best mounted on the plant floor.
Because RFID readers do not rely on line-of-site to obtain data from tags, the product and its tag can be placed in virtually any orientation.
Legacy RFID operates at 125 kHz, but its modern incarnation typically adheres to the 13.56 MHz standard—making its operability considerably faster than older systems. Also, while many legacy RFID systems allow only static read-and-write operations, modern systems are capable of reading and writing data at all times.
Memory in the tag
Today's systems may use a newer memory storage technology to extend operational life. RFID tags currently use either electrically erasable programmable read-only memory (EEPROM) or ferroelectric random access memory (FRAM) data carriers. Each allows unlimited read operations; FRAM allows data to be processed by a power of ten times faster than EEPROM technology. At this speed, FRAM-based tags allow data transfer rates for reading and writing at speeds higher than 10 ms.
In addition, FRAM data carriers can withstand significantly more write operations than EEPROM tags, which usually offer 100,000 write cycles—meaning users could write to the tag every second of the day for a one-day period. FRAM data carriers, on the other hand, allow up to 1 billion write operations.
Even at 100,000 write operations per day, this equates to a service life of 27 years—making data carrier replacement practically unnecessary. These new features, combined with several key advantages over conventional barcode technology, have further convinced many manufacturers of the benefit and increased ROI that RFID can provide.
RFID delivers rugged, long-lasting operation in often-harsh production environments - such as in this application, where RFID technology is used to identify metal carriers throughout the entire manufacturing process.
Barcode sticker problems
In commercial applications, such as in retail, barcodes are used to correspond with a certain product and are often placed on stickers on the products. Retailers benefit because most only need to track products for inventory purposes, rather than product quality or quantity (which takes place at the manufacturing level). Only one barcode is needed per type of product, so fewer types of tags are required. And since the products are simply placed in storage or on a shelf—not undergoing harsh manufacturing processes—placing this data on a sticker will usually suffice. For industrial purposes, however, a far different tracking technology is required.
While barcodes have been typically used for WIP, they often can't stand up to the environmental challenges these applications pose. Stickers peel off, and the numbers can easily rub off or become distorted by water, oil or simply frequent use. In some automotive applications a barcode may need to be applied three or four times during one production cycle. This adds up to significant replacement costs and, more than that, a low degree of reliability in harsh plant environments—resulting in an increased likelihood of producing rejects or, as the case may be, not catching the rejects that are produced.
While this can prove very costly to a manufacturer, the process also costs companies more time. Unlike RFID technology, barcodes rely upon line-of-sight to obtain readings. A product must be properly aligned on the production line for the barcode reader to identify the product by its code. For oddly shaped products, such as automotive components, maintaining the proper orientation can take some time and effort. Instead, manufacturers will oftentimes have line workers manually scan each barcode as the product passes down the line.
This requires extra time for the product to be picked up, oriented, scanned and replaced on the line—significantly reducing production speeds—and adding the risk of manual errors into the mix. The costs of producing or not catching rejects, now combined with slower production, makes barcode technology more expensive than RFID.
Additional modules may be added to the system, making a separate gateway for RFID and analog and discrete I/O unnecessary.
Many benefits over barcode technology
When RFID replaces barcode technology in industrial applications, it offers many benefits over its barcode counterpart. Because RFID tags contain all electronics within a rugged, protective housing, they offer exceptionally high durability—even in dirty or wet production environments. Plus, the tag can be placed in virtually at any orientation on the component, because RFID readers can identify tags even at a 90-degree angle.
This improves production efficiency in two ways: first, by eliminating time on the front-end needed to orient the product properly; and second, by eliminating the need for manual operators scanning products on the production line. Consequently, this also reduces the risk of manual errors.
The robust design of RFID tags ensures that manufacturers experience significantly fewer replacement costs, as these tags offer an unlimited number of read operations. As mentioned, when FRAM data carriers are used, along with higher speeds the carriers provide 1 billion write operations apiece—providing users with the ability to assign 1 billion variations of automotive component colors, date stamps, composition details, or virtually any other need-to-know information about the components as they come down the line—which can result in decades of use for each tag.
Since each tag can contain unique serial code data, RFID readers can scan one product and track it throughout the manufacturing process. This ability helps to eliminate the production errors often missed by barcode technology. By placing an RFID reader at each stage of production, manufacturers can identify whether a component has skipped a stage. For example, if a product passes stages 1 and 2, then ends up at stage 5, the reader can identify that the product has skipped stages and immediately divert the reject from the production line.
Ability to track individual products also helps prevent counterfeit products from slipping in along the way—often a concern in pharmaceutical manufacturing processes. Stringent quality requirements from the U.S. Food and Drug Administration (FDA) are driving manufacturers to implement RFID technology to embed critical information—such as a product's raw materials, what batch it was created from, the original manufacturer, and so forth. And this information can be tracked throughout production and even through distribution. This allows companies to readily identify if a counterfeit product—one without the necessary drug pedigree—has been added into the mix, then remove it promptly before the product reaches consumers.
Similarly, RFID can now be used in food and beverage applications to help identify potentially harmful or foreign materials. For example, users could employ RFID to track the processing location and batch of product for each ingredient they incorporate. If users discover a certain batch of materials was tainted, they could check their records and confirm where each of their product's components originated—quickly determining which products may be tainted. Also, this system may help users identify foreign elements that may have infiltrated their products. For instance, if an ingredient from a batch containing peanuts were to be accidentally mixed with a product meant to contain chocolate alone, RFID technology can help users identify and remove rejects during production—which could be critical for consumers with peanut allergies.
When RFID technology is incorporated into standard senseing housings, it provides further ease-of-use for operators familiar with mounting sensors on the production line.
The combination of assured product quality, increased production speeds, and higher durability for reduced replacement costs has typically resulted in an ROI within 12 to 18 months in many applications—including pharmaceutical, food and beverage, and automotive industry applications. For example, automobile manufacturers may produce 1,000 vehicles per day. Robots costing upwards of $200,000 are used to apply barcodes to the vehicles to track them through the manufacturing stages. These vehicles are put through some rigorous processes that often ruin ordinary barcodes. In some cases, a barcode must be reapplied three or four times before that particular vehicle is through production. So, it's not only the initial cost of the barcode-applying robot, but also the cost to maintain these machines and replenish barcode supplies.
With RFID, because the tags are specially designed to withstand the harsh environments, they can be installed once on the vehicle carrier and used over and over again—up to a decade in some instances—for tracking the vehicle through production. If RFID costs $100 implement one carrier and there are 1,000 carriers throughout the plant, that $100,000 is still far less than the cost of just one robot. Plus, this investment will last for years with virtually no maintenance or time lost in production to replace bad barcodes.
In addition to these benefits, RFID technology improves data management by offering simple integration into control environments. With the appropriate interface technology, data collected from RFID readers can be communicated using industrial networks such as Profibus-DP, DeviceNet, Modbus TCP, Profinet, EtherNet/IP, and others, allowing users to employ technology already instilled in their operations to store data and control processes accordingly.
Using a preexisting control system to implement RFID may help users realize ROI more quickly. Typically, only two channels of RFID could be implemented on a single node on the network. However, recent system upgrades have allowed up to eight channels of RFID on one node. Additionally, it is possible to integrate RFID with other analog and discrete I/O points on the same node within the network—rather than requiring two separate gateways. With this arrangement, integrating RFID into an existing network is as easy as adding a slice onto the gateway—delivering a comprehensive, easy-to-apply and long-lasting solution.
Mark DiSera is RFID product marketing manager for Turck.
What RFID does for manufacturing
Simatic RF310R and RF380R RFID read/write devices from Siemens Energy & Automation Inc. now accomodate advanced and simple transponders. These high frequency 13.56 megahertz range devices have been redesigned with ISO 15693 functionality, making them suitable for tags with little memory, including the affordable MDS d100 and D124 ISO 15693 tags, as well as more sophisticated tags in the RF300 transponder range.
Manufacturing customers using radio frequency identification (RFID) systems, says Ed Housler, business manager discrete automation—factory sensors, Siemens Energy & Automation Inc., are finding that RFID helps:
Improve return on investment (ROI) by improving their processes and providing real-time visibility of the factory floor.
Pinpoint bottlenecks and inventory levels.
Gather information in an automated manner providing a high level of data reliability.
RFID has been used on the factory floor for decades in a wide range of industrial applications.
Improve processes in all markets with hardware that can be installed in high temperature, corrosive, and physically demanding environments making RFID feasible in applications that in the past would not have been possible.
Retrieve recipe data from the tag, which can support an automated manufacturing cell; process data can be written to the RFID tags as well.
Store multiple sources of data on the tag and transfer it to master data records once the part is complete.
ROI calculations for implementing a RFID system can vary dramatically depending on the level of visibility required, Housler says.
A leader in seed breeding, for example, has used RFID to provide 100% visibility of preprocessing harvested crops, he explains. This was important to its processes because the misidentification of a single sample—either lost or not positively identified—would render that sample worthless and could set their evaluation of crop production back an entire growing season.
Edited by Mark T. Hoske, Control Engineering Editor in Chief,MHoske@cfemedia.com
Is RFID right for your application?
Users must consider several factors to determine if an RFID system will improve operations and provide a significant ROI.
Determine what data must be acquired from the products or components and how that data will be used. RFID is most commonly used for quality control—so begin by looking at existing quality control systems and what issues, if any, have been problematic. This helps determine where RFID should be applied, as well as helps measure ROI after installation.
Consider project scope or plant scale when deciding if RFID is right for the application.
Understand application requirements, because not all RFID systems are created equally. If the application involves extremely high temperature environments, like painting or curing systems, and the RFID tag will also be enduring the same process, users must specify their needs before implementing the system.
Do the math. If the solution cost exceeds the value of the benefits RFID will provide, including reduced errors or labor, then RFID may not be right for that application—yet.
Ensure that the technological expertise is in the RFID system and with your service provider for dependable operation on the production line, and for reliable support when you needed.
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