Track and trace offers opportunities for machine vision vendors
The aerospace, automotive, health care, and pharmaceutical industries need to track products as they move from manufacturing to the customer to stop illegal, counterfeited items from reaching the end user. According to the Organization for Economic Co-operation and Development, counterfeit products are produced in many countries, with China being the largest producer.
Counterfeit products range from spare parts, pharmaceuticals, and luxury items such as watches to food and drink, medical equipment, and toys. Substandard, spurious, falsely labeled, falsified, and counterfeit (SSFFC) medical products may cause harm to patients and fail to treat the diseases for which they were intended.
Tracking can counteract this problem. It allows manufacturers and customers alike to determine the current and past locations of items and to determine which companies or customers have come into contact with them along the supply chain.
Serialization and aggregation
Such tracking and tracing demands both serialization and aggregation. Serialization is used to assign a unique, verifiable product identification code to a particular product. Aggregation allows manufacturers to assign the codes to packaging containers such as blister packs, as well as to cartons, shipping cases, pallets, and shipping containers. Once codes are assigned, a "child and parent" relationship is established. It links the hierarchy of packaging and may, for example, allow scanning of a shipping container to identify all the contents of the individual packages within.
Unfortunately, while many companies have adopted serialization methods to uniquely identify products, aggregation methods are not yet deployed universally as part of track-and-trace regulation. The United States, Brazil, China, the European Union, India, and South Korea all require different levels of aggregation for pharmaceutical packaging.
While those along the supply chain may be the first to reap the benefits of aggregation systems, the cost to deploy them lies with manufacturers. And while universal serialization processes may not yet be commonplace, serialization methods are now found in many manufacturing facilities.
A number of different methods and tools can be used to serialize a product. These range from human-readable characters to radio frequency identification (RFID) tags to one- and two-dimensional (1-D and 2-D) barcodes.
Perhaps the most common tools are barcode reading systems. Both laser-based and CMOS-based barcode readers can read and verify barcodes applied directly using an ink-jet printer, applied by a peening process, or printed on a label attached to a product.
Those developing serialization systems using barcodes have a number of different options, depending on the product to be marked. While consumer products may have 1-D barcodes, products such as printed circuit boards and semiconductors may require small, more compact 2-D barcodes. One-dimensional barcodes, such as UPC codes, encode data in parallel lines of varying widths and spacing. These are used in retail. Two-dimensional Data Matrix codes are more suitable for smaller items, such as electronic components, since they allow alphanumeric data to be stored in a compact 2-D grid format.
Industrial laser-based barcode scanners are available from companies such as Microscan and Datalogic. However, although such scanners are fast, they generally are not used to read 2-D codes. This has led these companies and others, such as Cognex, to develop image-based barcode readers that can read both 1-D and 2-D symbologies. Two-dimensional scanners can also read barcodes in any orientation within a single view.
According to David Petry of Siemens, British American Tobacco is using Siemens’ Simatic MV440 code-reading system for reading serial numbers of cigarette cartons printed as Data Matrix codes. Later in the serialization process, the cases used to track the cartons are also identified by serial numbers, linking the cartons and cases hierarchically.
"The ongoing implementation of product serialization to meet track-and-trace standards and regulations has brought about the continued development of the 1-D/2-D code-reading and verification technology," said Pierantonio Boriero, product line manager at Matrox Imaging.
Validation and verification
While the read rate of barcode readers is important, so is the quality of the barcode, which must be readable by other systems along the supply chain. "In auto ID and labeling," said Jonathan Ludlow, machine vision promoter at Microscan, "verification is the grading of a 1-D or 2-D code against a specific standard with the intention of predicting how easy it will be to read, while validation refers to checking the format of the content of the code to check if the agreed formatting standard has been applied."
In barcode verification, the barcode is read and inspected for attributes such as contrast and defects, after which a single grade is returned. To allow manufacturers to standardize this grade, the International Standards Organization (ISO) specifies methods of measuring the parameters of different barcode symbols for 1-D (ISO 15416), 2-D (ISO 15415 and ISO 29158), and direct part mark codes.
Whether RFID tags, human-readable alphanumerics, or 1-D or 2-D barcodes are used in the manufacturing process, implementing such systems demands more than choosing the correct serialization and verification solutions. Indeed, to be most effective, all systems must be easily accessible using middleware, database systems, applications, and user interfaces. So manufacturers must incorporate both manufacturing execution systems for managing and monitoring information and enterprise resource planning software to integrate the purchasing, inventory, and sales of their products. "This depends on the specific application of the customer," Petry said.
Winn Hardin is contributing editor for AIA. This article originally appeared in Vision Online. AIA is a part of the Association for Advancing Automation (A3), a CFE Media content partner. Edited by Chris Vavra, production editor, CFE Media, firstname.lastname@example.org.