Louis Whitlock has a cruel exercise to demonstrate for his employees at Visteon Corp. the inherent waste in manufacturing. It's called “value stream mapping,” and Mr. Whitlock used it to tally exactly how much value seven Visteon plants create in producing instrument panels and associated components.

Mr. Whitlock, Visteon manufacturing director, shared the bare-knuckled results at last month's Traverse City, MI, automotive conference. He defines “value” as something the end consumer will pay for — an air-conditioning system, for instance. The consumer will not pay, however, to test, ship, package or inspect the HVAC system.

The exercise revealed that Visteon's Saline, MI, plant adds value only 0.26% of the time it takes to assemble a full instrument panel. It sounds minuscule — until compared to Visteon's glove box plant in Benton Harbor, MI, which adds value only 0.05% of the time, Mr. Whitlock says.

That's not to say everything else is waste. Mr. Whitlock says certain processes are unavoidable in manufacturing, but value stream mapping can achieve major improvements. Toyota Motor Corp., with its revered production system, achieves 10% of value-added with its vehicle manufacturing process, Mr. Whitlock says.

Why do such a gut-wrenching exercise? Because Saline supplies complete instrument panels just-in-time to Ford Motor Co.'s Michigan Truck, Wixom and Wayne assembly plants. And Mr. Whitlock reports that every minute of downtime at Saline costs Visteon $100.