The 5 Whys — A Ramen Shop Story

A Japanese ramen chain discovered that 60% of its negative reviews focused on "waited too long." The manager's first instinct: the kitchen is too slow. He pressured the kitchen staff and even considered hiring more hands.

But they used the "5 Whys" method to investigate — a technique invented by Sakichi Toyoda in his textile factory in the 1930s: ask "why" five consecutive times until you reach the root cause.

1. Why did customers wait too long? → Because it took more than 15 minutes from ordering to food arriving.
2. Why did it take 15 minutes? → Because the kitchen was slow to respond after receiving the order.
3. Why was the kitchen slow to respond? → Because the order ticket printer was delayed.
4. Why was printing delayed? → Because the system bottlenecked during peak hours.
5. Why did it bottleneck? → Because the buffer size was set too small.

The root cause wasn't "slow chefs" but "the ordering system's buffer setting."

The fix took only 10 minutes, at near-zero cost. But it reduced "waited too long" complaints by 70%.

What if the manager had chosen to hire more staff? The problem wouldn't have been solved, labor costs would have increased, the kitchen would have become more crowded, and efficiency would have actually declined.

Toyota Production System architect Taiichi Ohno once said: "Ask why five times and you'll find the real cause. Stop at two or three, and you'll only find symptoms."