Wireless LANs 'critical' for GM

The automaker expects payback within a year.

Viewing wireless LANs as a mission-critical infrastructure for its manufacturing operations, General Motors Corp. by year's end will have installed them in all 25 of its North American assembly plants.

GM will initially use the massive in-plant wireless LAN infrastructure to track materials and replenish parts at stations on its assembly lines. But once the wireless LANs are in place, according to Clif Triplett, global information officer for manufacturing and quality at GM, they can be used to support a wide range of other applications. Those include access to computer-aided design drawings and plant configuration information, which Triplett called a "virtual factory" database.

Larry Graham, global manager of manufacturing technologies for GM, said the factory wireless LAN infrastructure will bring about a "quantum change" in the ability of GM to send and receive information to and from workers and systems in the manufacturing environment. "It provides you with agility and flexibility that did not exist before," Graham said. GM plans to standardize on Wi-Fi, or 802.11b, wireless LAN technology in all of its plants, he added.

The rugged enclosures for the access points and the tuned, directional antennas required to propagate a signal inside a plant without having it spill outside cost $1,000 each.

But Graham said GM expects a quick payback on its investment—less than one year. He declined to elaborate further on the financial details.

Jack Maynard, an analyst at Boston-based Aberdeen Group Inc., said the fact that GM expects to recoup its investment so quickly indicates that the company had "a real problem" with locating parts expeditiously and efficiently.

Maynard added that GM could use the wireless LAN-based materials management system to drastically change its manufacturing operation to a build-to-order model.

GM has already equipped 75 to 100 forklift trucks with wireless terminals in each plant. In its New United Motor Manufacturing Inc. plant in Fremont, Calif., which it operates jointly with Japan-based Toyota Motor Corp., GM has installed a wireless location system from WhereNet Corp. in Santa Clara, Calif., that works with the wireless LAN.

When workers need to replenish parts for their station, they press a button on a wireless pendant at their workstation. The request is displayed on a screen on the forklift, showing the location of the worker and the materials required. Triplett said he views vehicle-tracking information as another high-priority application for the wireless system.

Ford Motor Co. and DaimlerChrysler AG both operate extensive wireless LAN networks at their North American manufacturing plants, but neither currently has plans to install an infrastructure equal in scope to GM's.

Jim Buczkowski, director of manufacturing and supply chain IT at Ford, said the company has installed wireless LANs at all 21 of its North American assembly plants, but with zoned coverage rather than plantwide coverage.

Ford uses wireless LANs in the yards of all its plants to control and manage finished-vehicle inventory and has experimented with installing wireless terminals on forklifts, Buczkowski said. But Ford hasn't been able to justify a business case for wide-scale rollout of wireless terminals on forklifts, he said.

Elive Likine, manager of wireless communications at DaimlerChrysler, said the company has older wireless LANs that operate in the 902-MHz band that are used to support yard operations. The automaker has also installed 802.11b wireless LANs, which operate in the 2.4-GHz band, at some of its plants to support specific applications such as "end of line" testing of electrical components.

DaimlerChrysler plans to stick with the 902-MHz wireless LANs for now because "we do not see a business case to shift from 902 MHz to 2.4 GHz," Likine said.


GM LANscape

GM's wireless LAN infrastructure will cover 25 manufacturing plants; 35 to 65 access points will cover an 80-acre plant.


Access points from Cisco Systems Inc.; rugged devices running Microsoft OS supplied by Symbol Technologies and Intermec Technologies Corp.


Materials management


Real-time location system; access to "virtual factory" database and CAD drawings


Less than one year


128-bit Wired Equivalent Privacy; subnetted VPNs; tuned, directional antennas


Designed for upgrade to 54M bit/sec. 802.11a or 802.11g

Copyright © 2002 IDG Communications, Inc.

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