Reading right

Like many fashion retailers, Forever 21 has seen steady growth in online orders for its women's apparel. To help keep up with the e-commerce-fueled demand, the company three years ago installed a EuroSort bomb bay sorter that's capable of handling 28,800 items per hour.

Under the current work flow, workers batch-pick items for multiple orders and place them individually onto "trays" or compartments on the sorter track. As each item passes by, a fixed laser scanner reads its bar code. Based on that read, the sorter's software tells the system when to release the item. At the right time, the system opens the tray, much the way a military aircraft's bomb bay doors open, gently dropping the item into the appropriate destination bin below.

In the early days, however, things did not always flow according to plan. The problem lay with the bar-code scanning process. Like many retailers, Forever 21 relies on its suppliers to affix bar codes to the merchandise, and the results are often less than optimal. For example, sometimes items arrive with their codes smudged or wrinkled by the fabric. That proved problematic for the laser scanners, which can only scan one line at a time and were unable to capture the necessary data. Other problems occurred when items arrived in plastic bags that reflected light in such a way as to interfere with the read. That also proved tough to resolve because the sorter's units are fixed, meaning they cannot be repositioned easily to catch the optimal read angle.

As a result, the laser scanners were failing as much as 4 percent of the time, which equated to as many as 1,500 sorts per hour. "That required us to pick up the units that were not read and sorted, research where they were supposed to go, and then manually take them to the matching station," explains Jason Kim, the company's project manager. Forever 21's order pickers had to spend about 15 percent of their time simply replacing faulty bar-code labels or repositioning items to improve read rates.

To solve the problem, Forever 21 replaced the laser scanners on the sorter with Cognex DataMan 503 image-based ID readers. The readers capture the entire bar-code image instead of a single scan line at a time. The software then uses a series of sophisticated algorithms to complete the read. This allows the readers to process most codes that are smudged, scratched, or printed with colored ink.

Since the company replaced the scanners last year, misreads are down to about 1 percent, and almost all of these are due to missing bar codes or labels that were improperly placed on the garment by the supplier. The improved accuracy has also virtually eliminated the need for pickers to replace faulty bar-code labels. Cognex estimates that Forever 21 has saved $1 million through improved read rates and reduced handling.

"The readers allow us to optimize our sort capability, which saves the labor of manual sorting. We can now process more units per hour and turn our orders faster," says Kim.