To support the output it needed, Green Mountain decided to increase automation at its main distribution centre in Waterbury, Vt. Products are stored in aisles that are each 60 yards long. Material handling systems specialist Diamond Phoenix was contracted to develop a customised warehouse control system (WCS) to integrate with Green Mountain's legacy enterprise resource planning (ERP) system from PeopleSoft. Integrated Labeling Systems (ILS), a Zebra Technologies Premier Partner, recommended new barcode label printers and processes to provide more time savings and efficiency gains.
Orders are picked during the day and shelves are replenished at night. Most of the aisles are picked and replenished manually by workers on forklifts, and a robotic automated storage and retrieval system (AS/RS) handles the rest. The new WCS receives orders from the ERP system and directs all activity.
Forklift-based workers receive replenishment and picking instructions wirelessly on Symbol MC9000 mobile computers from Motorola's Enterprise Mobility Business. Cases and other items being placed into storage require a barcoded tracking label, and items being picked are relabeled with a barcode to associate them with the specific order. All labelling is done at the point of activity using Zebra® QL 420™ wireless mobile printers that are mounted on the forklifts. The WCS directs workers to specific aisle locations to pick or replenish products.When they arrive there, the PeopleSoft ERP system generates the specific label format and sends it to the printer in real time over the 802.11b wireless network.Workers immediately apply the label to the item.
"Mobile printing is a huge time savings," said Mitch Casey, MIS business manager at Green Mountain Coffee Roasters. "Having wireless connectivity comes in so handy."
Mobile printing helps keep transactions accurate and delivers many of the productivity gains from the optimized pick and replenishment routes the WCS calculates. Previously, labels were printed in batches and workers drove their forklifts to a central printing location to pick up labels for their picking and putaway routes. The practice made it possible to apply the wrong label to the wrong item. It also limited productivity, because workers made numerous trips up and down the 60-yard aisles each day just to retrieve labels.
"Our biggest concern about mobile and wireless printing was 'Would it work?'" said Casey. "Wireless coverage and signal strength is always a concern.
Plus, it is a warehouse environment, and the printers don't get treated with kid gloves.We wanted rugged machines that could be mounted securely.We found the Zebra printers to be both." And wireless coverage wasn't an issue either. Green Mountain takes advantage of the 802.11b wireless connectivity available for the QL 420 printers, eliminating the need to cable them to the mobile computers. The printers also help protect the wireless network, because they support the WPA wireless security protocol that Green Mountain is migrating to for securing its wireless devices.
A new S4M™ stationary Zebra printer with a ZebraNet® wireless network card is used to print 4-by-10-inch labels for items that are picked by the robotic AS/RS machine. Additionally, Zebra compact desktop printers are used to print case labels, as every product gets put into a case. Inventory turns quickly at the distribution centre, so Green Mountain Coffee Roasters doesn't need the endurance that thermal-transfer labels provide. During its system upgrade, the company decided to switch from thermal-transfer to direct-thermal printing for putaway labels, which has reduced expenses by eliminating ribbon costs. Green Mountain also uses Zebra industrial printers and has Xi™ series high-performance models in place to support other high volume labelling tasks in the distribution centre.
All told, Green Mountain Coffee Roasters uses four distinctly different Zebra product families—mobile, desktop, industrial/commercial tabletop, and high-performance. Each printer runs Zebra's ZPL® printer command language. Having a consistent platform simplifies things for Casey and his MIS staff.
ZPL support is embedded in Green Mountain's PeopleSoft system, which makes it easy to direct all print output from within the ERP applications with no middleware needed.
"We use so many printers here that we wanted to standardize," said Casey. "When the time came to start mobile printing, we already use so many Zebra printers we wanted to stick with them.We'd never even entertain another product in our warehouse for printing labels."