Interesting lean manufacturing technique: Ask Why 5 times

I found an interesting tool used by Toyota in its efforts of making the waste free manufacturing facility. Lean manufacturers always believe problems are the sources for improvement. Therefore every problem is an opportunity for improvement. So how lean manufacturing use problems to their advantage. Toyota’s website gives us a simple tool to use.

According to Toyota’s Taiichi Ohno, when you have a problem you should look at the problem and ask the question why five times. For an example lets say you have number of quality defects in transportation. So you attend the problem by asking why you get quality defects while you transport. When you get the answer to that question, most probably that answer itself will reveal a problem in the system. Do this over and over again until you get to the root cause of the problem. Then get read of this cause. Your problem will be solved automatically.

What is the important concept behind this? That is finding the root cause and treating it. Important message is not to treat symptoms, but to treat causes of the problems. This is the lean way of thinking.