Hats Off to Wireless

Jan. 1, 2007
Dorfman Pacific, a full-line headwear and handbag company known for its responsiveness to its customers, had a problem. Its manual, paper-based warehouse processes were responsible for costs of a quarter of a million dollars per year in temporary labor.

Most of Dorfman Pacific's hats are imported. Product lands at Oakland, Calif., and is trucked to its 275,000-sq.ft. warehouse in Stockton, Calif. It receives 15 to 20 container loads each week. Stockton managers wanted to streamline this product flow, improve inventory accuracy and reduce costs.

They took the first step toward improving operations by deploying HighJump's (Eden Prairie, Minn., warehouse management software and installing a wireless infrastructure from Symbol Technologies Inc. (Editor's note: The Holtsville, N.Y.-based company,, was acquired by Motorola in early January.)

"With the Symbol enterprise mobility system, our warehouse is now entirely paperless, resulting in streamlined warehouse processes and improved inventory accuracy," says Mark Dulle, director of information technology services. "While the return on investment for the Symbol Wi-Fi network came primarily from automating the warehouse in Stockton, a significant bonus will be to extend and deploy a Symbol Wi-Fi network at our new 65,000-sq.-ft. facility in Dallas."

Taking full advantage of the new technology's capabilities, Dorfman Pacific redesigned its picking system in order to optimize its new wireless infrastructure and manage its 25,000 SKUs. Pickers now pick by the case, scanning license plates and bar-coded locations on racks with long-range scanners. The warehouse can now handle double the number of orders during peak order periods, and overall labor costs in Stockton have been reduced by nearly 30%.

To implement the new technology Dorfman Pacific partnered with RedLine Solutions, Inc., a systems integrator based in Santa Clara, Calif. ( RedLine developed processes for bar code tracking and validation for products and material movement in receiving, receiving inspection, putaway, picking and packing, shipment confirmation and cycle counting. It took Redline three months to set up the Wi-Fi infrastructure.

Step-by-Step Installation
Many questions need to be asked and answered before installing a wireless network, according to Dulle. First, managers need to understand the flow of product and how the zones are going to work.

"You have to decide how much of the picking will be done through hand-helds vs. order pickers vs. pallet picking," Dulle advises. "Is the whole building going to be RF? Are you going to try to use PCs off of the same network backbone? If so, is your network designed to do that? You have to decide what you are going to use all of that wireless capability for, and how you are going to use it before you get started."

Installing a wireless network is not strictly an IT project. Operations and other departments that could be affected by the new system must be involved. A solid understanding of the company's flow of goods and the warehouse processes will help managers understand what changes are needed to take full advantage of the wireless network. Fortunately, Dorfman Pacific was able to draw on the experience of its own employees who had experience working in wireless environments.

"Make sure, if you do not have experience in [wireless networks] on your team, that you get some," Dulle emphasizes.

The next step in installing a wireless network is completing a radio-frequency study of the facility to determine the number and location of Wi-Fi access ports needed. "Planners doing the study will shoot an RF device to learn what the coverage is in the warehouse." That work will help determine how antennas are used, what kind of coverage the antennas will provide and what overlapping coverage is needed. Designers need to know how many access ports their facility needs to ensure the RF coverage throughout the warehouse. The number of access ports depends on a variety of elements, including the layout of the building, thickness of walls, rack height and product density, to name a few.

Dorfman Pacific needed 15 access ports, an unusually high number, in its Stockton warehouse because the building had been expanded three times since 1980, giving it an irregular layout with some interior cement walls. It also has a high density of product. In contrast, its new warehouse in Dallas consists of one wide-open space and will require only four or five access ports.

Some wireless networks exchange data faster than others. Dulles says it is important for managers to know how quickly they want their processes to run in order for the proper Wi-Fi network to be installed. The RF study will help determine the type and speed of the network. Don't underestimate the need to install fiber optic cable instead of copper.

"Don't go cheap. Spend the money on the fiber. It is not much more expensive," Dulle advises. He also recommends using inline switches, and putting a battery backup on every switch.

Dulle wanted a well-integrated system in which the access ports were a good match for the wireless devices that would be used. He also did not want to work with a lot of vendors. His team selected Symbol because it could provide the access ports, handheld devises and truck-mounted devices. The Symbol AP300 dual-band switch that they installed is capable of transmitting data on two different frequencies.

During the installation process, the company also upgraded its network to a Cisco-based system using Cisco 6509 switches and ran fiber optics to key points throughout the warehouse. Inline power switches were also installed. Access ports can be either powered or non-powered, which means that electricity can be run to each access point in the ceiling or use a non-powered access point that draws its power from the switch. Access points that draw power from the switch may require fewer electrical lines. Having access ports that draw power from switches can also help keep workers productive during power outages. During a recent power outage at the warehouse, backup power on the switches kept the access points operational and lift truck operators were able to keep working.

All of the access ports in Dorfman Pacific's warehouse go through the network to a Cisco 6059 switch and then to one of Symbol's WS 5000 switches. The WS 5000 dual inline switch is tied into the Cisco backbone, which allows for remote management, diagnostics, maintenance, and traffic management on all of the access ports.

Both the Symbol and Cisco switches are designed to work in a virtual large area network. The technology lets programmers configure one network as if it is multiple networks, where data can be routed from one vlan to another. Dulle and his team redesigned their network so that PCs and Apple computers are on separate virtual networks, while the warehouse is on another virtual network. Data can be routed from one vlan to another.

Finally, when setting up a wireless network, Dulle strongly recommends developing a disaster recovery for the network backbone that includes both the hardware and the wireless pieces.

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