The 2D revolution — evolving business needs and improved technology are driving growth in two-dimensional bar coding

Two-dimensional bar codes have quietly revolutionised many production, tracking and maintenance processes. Now, 2D bar coding is undergoing a revolution, thanks to important scanning technology advances and growing use in multiple industries. 2D applications are now being adopted at more than double the rate of traditional 1D bar code technology.

Two-dimensional bar codes have always given organisations a reliable way to include information associated with a shipment, product, part or component, and are often the only practical option for accurate small-item identification. Two-dimensional symbologies have enough capacity to include intelligent data that can be used to drive decisions and processes in environments where traditional information systems don’t reach. In fact, they are sometimes referred to as ‘portable databases’ or ‘portable data files’. If processes or workers could benefit from having more information, 2D bar codes are increasingly being used to provide it. Now that area imaging technology improvements have eliminated most of the functional and practical limitations to using 2D bar codes, 2D applications are poised to revolutionise many business operations.

To understand how, compare how 1D and 2D applications typically work. Most traditional 1D applications use the bar code symbol, in the same way that a car ‘number plate’ is used, to encode a reference number to access information held in a database.

Number plates on cars do not tell the make and model of the vehicle or identify the owner. The plate number simply provides a unique number that corresponds to a database record with the information. Most 1D bar code applications are built on the same principle, which means the data encoded in the bar code has no use or value if it can’t be associated with a database record. One of the great values of 2D symbols is that they can encode enough information to drive applications that do not need database access. For example, in field service applications, technicians with no remote database access can simply scan a 2D code on a piece of equipment to get all the identification and configuration information necessary to complete the service work. The consumer goods and pharmaceutical industries also take advantage of 2D bar coding as an alternative to database access.

Figure 1: PDF417 take their name because they can resemble a series of small linear bar codes that have been stacked on top of each other. Leading stacked symbologies include PDF417, Code 16K, Code 49 and a version of GS1 DataBar formerly known as RSS Composite.

Many consumer goods and pharmaceutical manufacturers use 2D bar codes to supplement identification labels with lot codes and expiration dates. The data is used throughout the supply chain to support many decisions and processes to ensure proper stock rotation, expedite shipments, remove unsaleable products from inventory and facilitate efficient tracking and recalls. Because the data travels with the products, access to the product manufacturer’s information systems is not required for these applications. Logistics providers, wholesalers, retailers and other organisations in the supply chain can get the product identification and expiration data they need directly.

2D to the mainstream

These examples illustrate the benefits of 2D bar codes — and also illustrate why a commonly held perception is no longer true. Until recently, 2D was widely considered a ‘niche’ technology, beneficial only for a few industries and processes.

This perception has outlasted reality, because 2D adoption today is increasingly varied and widespread. With adoption growing rapidly in industries including manufacturing, maintenance, pharmaceutical and retail, in applications including production control, maintenance, product authentication, distribution and inventory management, 2D can hardly be considered a niche technology any more.

Product identification

Matrix codes occasionally appear on consumer goods packaging to supplement the UPC/EAN symbols with batch or lot codes and for product authentication. Now GS1, the international standards body that created the symbology and also manages the UPC/EAN system, is bringing 2D coding into the retail mainstream.

Figure 2: GS1 DataBar Composite combines 1D and 2D elements in a single bar code symbol.

GS1 has established 1 January 2010 as the ‘sunrise date’ for requiring scanners used at the point of sale and other retail operations to read and decode GS1 DataBar symbology bar codes. The GS1 DataBar family includes both stacked and composite 2D bar codes that can be used to encode standardised application identifiers (AIs), including lot codes and expiration dates, and others that can support enhanced security through authentication and traceability. GS1 estimates 85% of retail scanners will be DataBar capable by 2010. GS1 made the decision to require DataBar after receiving extensive input from manufacturers and retailers who felt UPC/EAN symbols were too large and inflexible for encoding the information they wanted.

In its business case analysis for DataBar (available from www.gs1.org), the organisation asserts users can get a positive return on investment through reduced packaging, improved identification of small, loose and variable-measure items, improved category management, and by taking advantage of improved traceability enabled by additional data encoding.

Pharmaceutical and health care

Widespread 2D item identification may occur even sooner in the pharmaceutical and health care industries. In the US, numerous state and federal drug pedigree requirements typically require tracking chain-of-custody for prescription medications by lot code and/or serial number. RFID is frequently proposed for these applications, but 2D bar codes can handle the data requirements and often integrate more easily with legacy systems and processes throughout the supply chain.

2D symbols are also used on patient wristbands and this application is also poised to grow rapidly as more health care facilities implement scanning systems to take advantage of unit-of-use bar codes. Linear bar codes have proven problematic on wristbands because the symbols are long enough to be affected by the curvature of the wristband. This makes it difficult to read the bar code accurately because the scanner can’t always see the ends of the symbol which get obscured by the curve. Compact 2D symbols avoid this problem, plus they have the capability to encode more information than the patient identification number.

Industrial

Reliable performance on curved surfaces is one of the many reasons 2D matrix codes are the symbols of choice for industrial marking and tracking applications. Even when produced at sizes small enough for electronics components and other small items, Data Matrix and other 2D symbologies have the capacity to encode a unique serial number, lot code, configuration data, timestamps and other production information. Small 2D symbols can be read reliably with handheld or unattended fixed-position imagers in a variety of industrial settings, including automated routing and assembly, work-in-process tracking, data entry for quality control testing, product genealogy and lifetime tracking.

Many of the 2D standards and marking initiatives are being, or have been, developed to provide cradle-to-grave traceability of parts, assemblies and components.

Make-to-order and just-in-sequence manufacturing require more than basic identification and often need components to be marked with serialisation, sequence or configuration information. Organisations throughout the supply chain, including suppliers, product manufacturers, service providers, packagers and distributors, can all take advantage of the standardised information to exchange information and create their own records management applications — with no central database access required. For example, a supplier that needs to provide uniquely identified parts to a manufacturing customer could scan the 2D part ID during the picking and packing processes to validate the right items were included in the order and packed in sequence. 2D bar code verification is often preferred and more accurate than relying on EDI data in these situations, because shipments often move ahead of the processing of their corresponding EDI transaction. Technology advances Until very recently, technology limitations with area imaging often made it impractical for organisations to transition from legacy 1D bar code applications to use 2D symbols. Laser scanners cannot read all 2D formats. Area imager scanners, which excel at 2D reading, couldn’t read 2D codes at distances greater than an arm’s length. Selecting a scanning technology for 2D bar codes has historically required making tradeoffs, because no single scanner was able to provide all the symbology support, range, reliability and speed required in real-world environments.

Figure 3: Data Matrix 2D codes encode data in dark and light geometric elements arranged in a grid. The position of each element relative to the centre of the symbol is a key variable for encoding. Matrix symbologies are most commonly used for small item marking, and also for unattended and high-speed reading applications. Common examples include Data Matrix, MaxiCode, Aztec Code, Code One and QR Code.

Would-be users faced a choice of supporting multiple scanning technologies, or a single bar code technology. 2D adoption lagged as a result and its perception as a niche technology lingered.

Area imagers read bar codes by capturing a full image of the symbol and using image processing software to decode it. They provide excellent performance for bar code reading, because they can read traditional linear, stacked and matrix symbologies in any orientation — which is a major difference from other reading technologies. Omnidirectional (orientation-independent) scanning capability means users don’t have to arrange or align bar codes to read them, which results in more successful first-time reads, improved throughput, less operator fatigue and reduced chances of injury.

Area imagers can also be used to take pictures, and in fact share many components with digital cameras. These imaging capabilities also set them apart from other types of bar code readers and enable new applications, such as documenting the condition of goods delivered, inspection/quality control, form/signature capture, damage recording and more.

Despite this flexibility, area imagers have had limited adoption because of their traditional range restrictions. The same scanner used to read a 2D part mark couldn’t also read the location code of the warehouse shelf the part was picked from. That limitation led to application tradeoffs that stifled adoption.
With the development of a new generation of area imager scanners, these tradeoffs are now going away. Newly released area imagers are now available that can read both linear and 2D bar codes at distances ranging from a few centimetres to more than 16 metres, which opens up a whole new set of opportunities.

Taking advantage of new capabilities

These advances have made it possible to use a single scanner for picking and product ID operations that require near- and long-range scanning regardless of the symbology being used. The same scanner can be used during one shift for work-in-process tracking and other close-range scanning, and used again by another shift for picking and put-away operations.

It is now practical for manufacturers to encode lot codes, serial numbers, configuration data or other variable information on the products they are packaging to supplement the traditional 1D bar codes that are used for inventory and shipping applications.

The optics in new scanners such as the Intellibeam EX25 can successfully read bar codes from angles as small as 12° which gives users tremendous flexibility for reading symbols and improves first-time read rates. In a head-to-head test to measure how quickly a worker could scan 50 bar codes, which were applied to packages at different 90° angles, volunteers using a handheld computer equipped with the Intermec Intellibeam EX25 area imager completed scanning 66% faster than those using laser scanners. The test was designed to determine how much impact omnidirectional scanning has on total scan time, because in real-world conditions there are often inconsistencies in the location and alignment of bar code labels on items. Not having to align the bar code symbol adds up to significantly improved worker productivity.

Conclusion

Two-dimensional bar codes have long given users more information and traceability than 1D bar codes, however long-held perceptions about 2D bar coding limited their use. These perceptions are no longer true. 2D bar coding is far from a niche technology and usage is exploding, in large part because of recent technology advances that have made 2D reading more flexible, practical and reliable. Now users don’t have to give up long-range scanning and efficient legacy bar code processes to get the benefits of 2D. Autofocus area imagers eliminate the tradeoffs between symbology support and read range that users have historically faced. Bar coding revolutionised many operations, two-dimensional technology later revolutionised bar coding, and now long-range area imaging is revolutionising 2D. These changes are dramatic, but they are making 2D common. Millions of parts and products are already identified and tracked with 2D symbols, and millions more soon will be because of new standards, business requirements, and improved 2D readers.

*Jack Tay is Senior Marketing Manager, Asia–Pacific, Intermec Technologies.