CHARLESTON, S.C. -- Sometimes a factory has to undergo the manufacturing equivalent of a home remodeling.
For Behr America Inc.'s factory in Charles-ton, S.C., that moment came two years ago, when plant manager Tom Daffron was trying to figure out how to squeeze more production out of his plant.
The plant, which opened in 1993, builds radiators and intercoolers for heavy trucks. As production expanded, managers installed machinery wherever they could find some vacant floor space.
Since production of any given component ranged from a few hundred units per year to tens of thousands -- and since a radiator might have hundreds of parts numbers -- the plant was a study in complexity.
With pallets of parts piled up around each work station, it was impossible for managers to see what was going on throughout the plant. The 350,000-square-foot plant's floor plan grew increasingly cluttered as Behr added products for the 390 employees.
"In twenty years we had gone through a lot of upgrades," Daffron recalled. "We put pieces of equipment on the floor where they would cause the least disruption."
So in 2011, when it came time to install a new high-capacity furnace, Daffron eyed his material flow chart with chagrin. "It was the classic spaghetti diagram," he recalled. "We had a really complicated flow of materials."
During the recession, management could afford to ignore the plant's inefficient layout, but that wasn't possible when the trucking industry roared back.
The industry's unexpected recovery "highlighted our weaknesses," Daffron recalled. "We saw very quickly that things were going the wrong way."
In keeping with the principles of lean manufacturing, the plant had been divided into a dozen final production cells that assembled 750,000 heat exchangers a year.
Production cells -- typically U-shaped work areas with a handful of employees per station -- gained popularity when suppliers began to shut down traditional assembly lines.
High-volume assembly lines were difficult to retool for new production runs, and they forced the factory to maintain costly inventories of raw materials and finished parts.
But it's not enough simply to divide a plant into production cells. You also have to eliminate waste: excessive movement by workers, excess parts inventories, excess scrappage.
Behr's managers knew this, of course, but the plant had fallen into some bad habits.
So Daffron started a two-year journey in 2011 to rededicate his factory to the principles of lean manufacturing. The strategy rigorously eliminates unnecessary steps, from major movements of material to such mundane items as the number of steps a worker must take to pick up a part and install it.
What would it take to simplify product assembly at Behr's Charleston plant?
After huddling with John Butler, his production system manager, and facilities engineer Fred Reesey, Daffron decided to take a clean-sheet approach.
They would renovate the entire factory, but they couldn't afford to shut down for six months. The factory would have to maintain production during the renovation.
At the end of 2011, Daffron organized the renovation into 25 steps, which covered each major piece of equipment.
The team would change over each production cell whenever the customer to which its work as assigned was shut down for a model changeover or holiday. Or if that wasn't possible Behr would build up a five-day reserve of parts to keep customers supplied during the renovation.
Next, the team figured out how to reduce the factory's bloated inventory of parts and materials waiting to be used in manufacturing cells.
Pallets of parts typically were piled next to the assembly lines, forcing workers to waste time unpacking cartons and searching for components. These inventories also complicated production changeovers, since workers had to cart away the pallets of unused components from the line to a storage area.
"Material handling was difficult," Daffron recalled. "We had a lot of forklifts in the plant."
Under the new system, the team designed "kitting" carts that contained enough parts for 60 to 90 minutes of production.
The carts' capacity was sized to match the customers' orders. So when the work cell had produced enough components to fill a customer's order, the parts bins were empty.
Then Daffron's team asked the workers to design the cart's bins so that the parts were arranged in the right sequence for assembly.
Since the plant had kitting carts, Daffron no longer needed all those forklifts. Instead, the carts were formed into trains and towed to their spots along the production cells.
As the plant simplified production flow, the scrappage rate began to decline. Workers handled the radiators less often, eliminating opportunities for damage.
Truck radiators are bulky, typically measuring one meter long by one meter wide. Whenever a worker drops or mishandles one, there's a chance a cooling tube might be cut. Those tubes can't be repaired, so a costly radiator must be junked.
"That causes a lot of heartache," Daffron said.
With the new production system, the scrappage rate has declined 50 percent and productivity is up 20 percent. The plant also has improved its up time -- the time in which a machine is available for production -- by 10 to 15 percent, Daffron said.
In the wake of the renovation, the plant can meet production quotas with a five-day workweek, running triple shifts. That leaves weekends free for maintenance or occasional rush orders.
Now Daffron wants to prevent backsliding into bad habits. In the bad old days, managers would identify unused floor space for new machinery a few weeks before it arrived. Under the new system, management has laid out the plant's production cells with an eye to orders, say, one or two years down the road.
"This allows us to look forward to what might be coming," Daffron said. "We don't want to start the [renovation process] all over again. We want to make sure we've learned our lesson."