The most difficult part of lean is identifying a problem to work on. Hence, the last question in a lean improvement should be, “How could we have discovered this problem sooner?”
A lean correction from the food industry illustrates how critical this last question could be. The new oil supplier did not add preservative. The parts per million (ppm) calculation was difficult. When I gave the poundage of preservative needed to the oil tank farmer, he laughed. He would need a fork truck to add that much preservative!
I double checked my math with another type of oil that used the same amount of preservative. The computerized calculation was only one-tenth of the preservative needed. Incorrect math meant unsafe products left this plant for years. Extensive internal and external audits did not identify the problem.
How could we have discovered this problem sooner? The company had several identical plants. A oil tank farmer from another plant would have identified the miscalculation immediately. How many problems could someone from another, similar gemba easily discover? Was this problem the only reason the plant’s costs were lower than the other plants? Is the lowest cost a reason to celebrate or a reason to worry? Should all kaizen events include someone from a similar plant? Would both plants benefit? Who should we send? The last question usually leads to many questions.
The company was fortunate it did not suffer Blue Bell’s fate.