Last December, the staff at J. Jill's Tilton, N.H., DC finally saw the light—or in this case, the lights: 356 illuminated LED displays. After years of using a radio-frequency (RF)-based order fulfillment system, the facility was abandoning its handheld scanners in favor of something a bit flashier.
J. Jill, which sells women's apparel, shoes, and accessories, wasn't just updating its look, however. It was making the switch to accommodate growth. Originally a catalog business, the retailer has shifted its focus to online and retail sales. Since it opened its first store in 1999, it has pursued an aggressive expansion strategy, adding roughly 40 stores annually in the last few years. Its DC "network," however, has undergone no such expansion. The 425,000-square-foot facility in Tilton continues to supply all of J. Jill's stores nationwide (which currently number 231) in addition to filling online and catalog orders.
As throughput volume grew, it became clear that the DC would have to replace its old packing system with something speedier. "We had a decent rate with the RF," says Glenn Broderick, J. Jill's director of retail distribution. "Order fillers were doing 575 units an hour with 99.95 percent accuracy." But that wouldn't be enough to keep up with the company's aggressive growth plans, he explains. "We were looking to drive the throughput north of 800 units an hour."
The search for a replacement technology that wouldn't require significant modification to the material handling equipment (or extensive worker retraining) led J. Jill to light-directed order fulfillment technology. But instead of the more familiar pick-to-light technology, the retailer opted for a variation: a put-to-light system.
Put-to-light systems work in much the same way as pick-to-light systems, but in reverse. With pick-to-light systems, illuminated displays are mounted at stock items' storage locations to indicate to pickers which items to retrieve. With put-to-light systems, the light displays are instead mounted at packing stations equipped with stationary cartons used to collect items for individual orders. Instead of telling pickers which items to retrieve, the flashing lights indicate where to distribute them.
Late last year, J. Jill installed AL Systems' DynaPack putto-light system, a solution that incorporated 356 light display modules managed by a scalable software platform. Though the company expected to see a jump in productivity, Broderick says, it was still caught off guard by the size of the gains—and by the speed with which they were achieved.
Age of enlightenment
Light-directed order fulfillment technology is hardly new. The first pick-to-light systems date back to the '80s. Rapistan (since renamed Dematic) is generally credited with being the first U.S. material handling equipment vendor to offer the technology.
In the early days, the systems' use was pretty much limited to the cosmetic and pharmaceutical industries, where the need for order picking accuracy justified the cost. "They were used where products were high priced, consumer service was a high priority, and mistakes [in order picking] very expensive," says Stephen Small, vice president of marketing and sales for Lighthouse Selection, a maker of pick-to-light equipment in Manchester, N.H.
Before long, users noticed that the systems did more than just boost accuracy. They also boosted productivity, largely because workers no longer had to stop to consult pick tickets or scanner displays for directions. As word of the productivity benefits got out, the systems caught on with a broader base of users. Among them were a number of large retail chains, which began installing pickto- light systems during the '90s.
The technology is best suited to operations that require high-velocity picking of a limited number of stock-keeping units (SKUs). But it's important to note that those fastmoving items must be stored next to a conveyor pick line. "If you have to do a lot of walking for an order, you're not going to buy pick to light. You'll never get payback on it," says Steve Mulaik, a consultant with the firm Progress Group in Atlanta. "Successful implementation of pick to light takes place where confirmation and search time [exceed] the walk time."
In the last five years, voice-directed systems have emerged to challenge light systems for the order selection technology market. But pick to light still has the edge in certain applications, including high-decibel operations. "In a noisy environment, lights work much better than voice," says Jack Kuchta, executive vice president at the warehouse consulting firm Gross & Associates in Woodbridge, N.J. Stephen Small estimates the current market for pick-to-light systems at somewhere between $40 million and $50 million a year.
Pick-to-light technology has come a long way since its introduction. One result has been that light systems have become much cheaper and easier to install than they were in the past. A decade ago, outfitting a DC with a pick-tolight system meant physically hand-wiring a display module to every workstation in the network. The advent of socalled "bus technology" for electronic devices in the last five years changed all that. Bus technology standardizes datainterface hookups for electrical devices (the USB and FireWire technologies familiar to personal computer users are examples of bus technology).
"With bus technology, you don't have to hard-wire each display," says Tom Singer, a principal at the consulting firm Tompkins Associates, based in Raleigh, N.C. "You lay out a bus frame and it lowers the installation costs. It also makes replacement of the units more cost effective."
Integration costs have also dropped in recent years. As part of the installation process, a pick-tolight system's software must be linked with the user's warehouse management system (WMS), which feeds order information to the light system. In the past, that often meant costly custom programming work. Today, however, many vendors supply either pre-built interfaces or toolkits designed to make it easy to create the necessary interfaces. That's made light systems eminently more marketable, says Kuchta. "When you have to build the interfaces, it made the decision to install one more precarious," he says. "It's the interfaces that drive up costs."
Despite the advances in software and bus technology, taking the pick-to-light route still requires a hefty investment. Singer says a company can expect to spend between $100 and $125 per light display. In addition, it should figure on spending another 50 percent for integration, even with the availability of pre-built interfaces. "If you have 10,000 lights, I'd figure $1.5 million for the system," says Singer.
The variation known as the put-to-light system, however, gets around that problem. With put to light, you don't need a module to identify the location of each SKU; you just need one for each order collection point. A DC that fills orders for 100 stores from a stock of 15,000 SKUs would need only 100 display modules, not 15,000.
Fast and accurate
Put-to-light technology is particularly well suited to specialty retailers that push a limited number of SKUs out to their stores, says Christopher Castaldi, a vice president of client development at AL Systems Inc. Like pick-to-light systems, put-to-light systems are designed for "dense picking" operations, where the SKUs needed for order fulfillment can be stored near the packing station.
J. Jill's operation is a case in point. Though the retailer's New Hampshire distribution center holds 38,000 SKUs, only 14,000 of those SKUs are supplied to stores. That makes it feasible to position these items close to the conveyors— a factor Broderick considers key to the system's success. "The put to light works for us because of the density of our picks," he says.
Installation was a simple matter of mounting the display modules onto existing two-tiered shelving— each module identifies the pack location assigned to an individual store. Though the company installed 356 display modules, only 231 are currently in use. That leaves more than 100 modules to accommodate growth.
Each pack station is located off a conveyor branch from the sortation system. At the start of the conveyor line, a worker takes a case of product from storage (each case contains a single SKU) or from a recently arrived inbound shipment that has been cross-docked. About 80 percent of J. Jill's merchandise is made overseas, primarily in Asia. The retailer brings the containers into the country through the Port of Long Beach, moves them cross country via rail, and finally trucks them to New Hampshire. Outbound orders move to its stores via UPS and to online and catalog customers with DHL.
Once the worker has selected a case, he or she breaks out the items—say, shoes—and puts them into a tote. Then the worker rolls the totes, two at a time, down a skatewheel conveyor located beside the put-to-light stations.
The worker first takes items out of one tote, depositing them into the cartons for various stores according to the instructions displayed on the put-to-light modules. The worker then makes a downstream pass, filling orders from that tote, and then returns upstream to his starting point, taking items out of the second tote. This approach allows the worker to distribute two totes' worth of a product in a single pass.
The new process has also cut back on the need for scanning. Before the put-to-light system was introduced, the order fulfillment process included two scanning steps. Workers first scanned each incoming carton of merchandise in order to get their packing directions, which popped up on the scanner's screen. Then, after depositing an item into a carton, they had to scan that carton again for verification purposes.
With the put-to-light system, by contrast, the worker scans the carton just once, at the beginning of the process. Almost instantly, the light modules at the appropriate packing stations begin to flash, displaying the required product quantities. Because there's no further need for scanning, workers don't have to take the scanners with them on their rounds anymore. "Now you're pretty much hands-free," says Broderick, "because you're not carrying that RF [scanner gun] around."
On the face of things, the changes brought by the new light system might seem insignificant. But taken together, they've done a lot to rev up the operation. For example, eliminating the need to perform a verification RF scan has cut a whole step out of the packing process, speeding up order fulfillment with no sacrifice in accuracy. On top of that, the DC has found that workers are more productive now that an associate can empty two totes in one swing down the conveyor line through the pack zone.
Although J. Jill knew fulfillment rates would rise, it didn't realize how big the gains would be. "It almost doubled what we were expecting in productivity," says Broderick. The company was looking for a gain in the 20-percent range, he explains; but after two months, it was clear that the new light system had actually boosted efficiency by a whopping 40 percent.