Saturn - 10 years later

By Gary R. Forger, Editorial Director -- Modern Materials Handling, 11/1/2000

Our cover story this month on the new Saturn assembly plant in Wilmington, Del. runs exactly 10 years to the month after we covered the original Saturn plant in Spring Hill, Tenn. And in its own right, each facility is a mirror of its times, and a milestone in materials handling practices.

In retrospect, the greenfield 4.1 million sq. ft. plant in Tennessee was quite different than originally proclaimed. When plans were first announced years earlier, the buzz (probably just called "talk" at the time) was all about "automatic guided vehicles and robotic workstations in a highly automated, computer-integrated (a blast from the past) manufacturing operation."

But GM blinked and generally opted for more conventional forms of handling. In fairness, this was about the time that automation for automation's sake was falling out of favor. Installed equipment included overhead automated monorail, an automated storage and retrieval system (AS/RS), inverted power-and-free conveyors, and lift trucks. There was also a relatively unknown skillet system, essentially a moving sidewalk that carries car bodies and workers as assembly continues through the plant.

Fast forward 10 years to Wilmington. The skillet is still a mainstay. So are the monorails, AS/RS, inverted power-and-free conveyors, and lift trucks. Sounds like Spring Hill was doing something right. But is history simply repeating itself? Not exactly. There's more to this tale of two plants than just the line up of materials handling equipment.

To begin, the Wilmington plant, which had been building cars since 1947, does not make components on site, unlike Spring Hill. Instead, facilities in Michigan, Ohio, and West Virginia ship parts to Delaware. By the way, both plants run counter in this regard to standard GM practice at their respective times.

But more importantly, each has its own standards for managing inventory. In Tennessee, the original idea was to limit materials in the plant to 1 day's production requirements. The Delaware standard is 3 hours. The Spring Hill AS/RS initially stored complete body panels for 900 cars. The Wilmington AS/RS stages up to 96 car bodies. Because that is the reverse of what you might expect given the production arrangements, those differences are a real gauge of how expectations have changed in 10 yr.

To support such low levels without choking the line, the Wilmington plant is fed by a 170,000 sq. ft. warehouse 8 mile distant. Enter returnable containers. In our 1990 story, returnables weren't even mentioned. (They didn't exactly have the high profile they do now.) In Wilmington, over 100 different steel, wire, and plastic containers are used to bring parts to the new assembly line. All were designed to maximize ergonomics (a word never found in the 1990 story although there was a reference to reducing worker fatigue), and ease of removing parts from the containers. Saturn also owns and manages all of the containers in Delaware, quite the reverse of the current practice in Tennessee.

In the end, each is a plant for its time and own particular situation. It'll be interesting to see how the story reads 10 years from now.