RFID Puts Things into Focus for Eyeglass Lens Maker

By Mary Catherine O'Connor

GKB Hi-Tech Lenses is using EPC Gen 2 tags to track and manage its production of prescription lenses, expediting the roughly 3,000 orders the company receives daily.


GKB Hi-Tech Lenses, based in Goa, India, manufactures optical lenses—enough to produce eyeglasses for 7 million consumers worldwide every year. But while it produces state-of-the-art lenses, the company—which operates through a joint venture with German optical manufacturer Carl Zeiss—has, until recently, employed an antiquated order-management system. However, with the help of S3Edge, a packaged-software provider of turnkey RFID solutions, GKB Hi-Tech has significantly reduced its order dwell time, while also boosting overall efficiencies—improving its order turnaround time by 23 percent.

When a consumer orders prescription glasses at one of the retail outlets that buys lenses from GKB Hi-Tech, the lens specifications are fed into a centrally operated order-management software application, which then assigns a unique identification number to that order. At the manufacturing facility, this number is used to call up production details—the strength of the prescription, as well as other features, such as antireflective coatings or color tinting.

At the beginning of the manufacturing process, an employee prints out an order—generated with a bar code encoded with that particular order number—and retrieves a pair of blanks used to create a set of eyeglass lenses, upon which various processes are carried out in order to give it the optical power required for that prescription. The printed order and the blanks are always kept together in a reusable container that is moved through each manufacturing step in the factory.

Under the previous order-tracking process, workers would scan the order form’s bar code at each station, thus enabling the order-management system to receive updates regarding each order’s location in the manufacturing process. However, that method did not provide a means for the order-management system to alert employees when a particular order needed to be rushed in order to meet a short delivery deadline. As a result, some orders were completed later than they were supposed to be, while others were fulfilled sooner than required.

The company needed a means of messaging workers to prioritize certain orders. This is where RFID has improved the manufacturing process.

Now, upon initiating a project, a worker still prints that order and scans the bar code printed on it. But when he does so, an RFID interrogator at his manufacturing station collects the unique code encoded to an EPC Gen 2 UHF passive tag attached to the container that will carry the lenses from one station to the next. S3Edge’s RTVS (real-time visibility systems) software, built on Microsoft‘s BizTalk RFID middleware platform, controls the RFID reader and is also linked to the order-management software. The RTVS software associates the order number, collected from the bar-code scan, with the RFID tag number. Prior to installing the RFID system, workers at subsequent stations had to manually scan the bar code on each order they received, in order to update the order-management system regarding the lenses’ progress and location. Now, an interrogator mounted at each station automates this job, continuously reading any nearby tags.

At each station, the RTVS pulls details from the order-management software, then utilizes this data to display alerts on a video monitor. Based on the order specifications and the completion deadline time, for instance, the software determines the maximum amount of time a given order can remain (or dwell) at a given station before being moved to the next manufacturing step. If an order remains at a particular station for more than this allotted time, the RTVS triggers an alert to the appropriate worker that one of the orders in his queue needs to be given priority. This alert is displayed on a monitor at the station, along with the order number, so that the employee can locate the order and work on it next. If, for some reason, the worker fails to process the priority order soon after this first alert, a second alert is displayed, presented in red, and the software can also trigger an e-mail or SMS message to a plant manager, alerting her to the delay.

In addition, the software can send alerts if an order is brought to a station at which the manufacturing step performed is not required for that order, thus ensuring that the order is properly filled and not unduly delayed.

Manish Soni, GKB Hi-Tech’s general manager, says the RFID system has enabled the company to greatly eliminate delays that previously resulted from the workers’ lack of awareness regarding the priority of the orders they processed. In fact, he says, the company has reduced the number of orders that are completed late by 80 percent, while improving its average order turnaround time by 23 percent. What’s more, Soni adds, order accuracy rates have improved, and are now at 98 percent.

The real-time visibility is also providing GKB Hi-Tech with a means of performing more detailed performance auditing than was previously available with the bar-code work-in-progress tracking system. This should help the company further hone its order accuracy and turnaround times.

S3Edge elected to install ThingMagic‘s Mercury4 readers—each of which supports four bistatic antennas—at each of seven stations in the manufacturing facility. UPM Raflatac produces the RFID tags, which measure 2 centimeters by 10 centimeters (0.8 inch by 4 inches) in size, and are embedded in a durable PVC laminate and attached to the reusable containers carrying the orders-in-progress. At present, the facility has 5,000 tagged containers, which it uses to process the roughly 3,000 orders it receives each day.