Radical New Way to Build Vehicles

THERE IS A NEW, BETTER WAY TO BUILD cars, and it does not require a traditional assembly line. That's the premise of a startlingly different way of looking at manufacturing from former auto executive Thomas Crumm.

I put Crumm's insight right up there with the best thinkers of the modern industrial era, from Frederick Winslow Taylor, whose ideas about efficiency and scientific management shaped 20th century assembly lines to visionaries such as Taiichi Ohno, the father of the revolutionary Toyota Production System.

In his fascinating book “What Is Good For General Motors?” Crumm dissects the inefficiencies of the moving assembly line and shows there really is a different way to build vehicles; one that's far more efficient and requires much lower investment costs.

In my previous column, I outlined Crumm's basic ideas, but here are the details of how vehicle assembly works today and how he would change it:

A typical automotive assembly plant has more than 1,000 work stations where line workers install parts on a vehicle. That work is divided into many separate stations, so that each worker can be given simple repetitive tasks that do not require high skills.

Manufacturing engineers use a concept called “takt time” to figure out the build rate needed at each work station. If a plant is assembling 60 cars an hour, each work station has a 60-second takt time to complete its task.

The idea is to have each worker perform as close to 60 seconds worth of labor as possible while each car goes through the station.

Most plants achieve about 60% efficiency; the best ones hit 78%. That means most plants get 36 seconds worth of work, the best ones about 47 seconds.

But once employees complete their task, they have to walk back down the line to start work on another. It takes 17 seconds to walk back. Subtract that 17 seconds out of the work time and the inefficiencies become glaring.

That means most plants get 19 seconds worth of work per station, and the best ones only get 30 seconds. In other words, in the best of circumstances the assembly line is only 50% efficient. That's pretty bad.

Crumm's solution is to put cars on moving platforms he calls rooms. He wants an assembly team of six journeymen, under the guidance of a master craftsman, to work in these rooms assembling cars.

The rooms move through different sections of the plant, depending on the equipment needed for welding, painting and other jobs. And the rooms move independently of each other, not nose-to-tail like cars move down the assembly line today.

The time spent traveling from one station to another is time spent working. Kits of components, sequenced in order of their assembly, are wheeled aboard the room as it passes by a warehouse with a specialized parts picking system.

This moving room assembly method also allows dissimilar vehicles to be built in a common factory, allowing up to 20 different models to be produced daily from a single small plant.

A few years back, automotive executives complained the business model was broken. Here's a way to fix it.

John McElroy is editorial director of Blue Sky Productions and producer of “Autoline” for WTVS-Channel 56, Detroit, and “Autoline Daily,” the online video newscast.