Problem: "Machine A cooling process stopped when running product C"
Physician-like approach: What are the 3 most common causes for stoppages in this process? Which one is most likely to happen? Set an action plan based on the experience with previous solutions from a similar case. In this approach, symptoms are gathered and a treatment plan is set to address the most likely cause. Past solutions are evaluated based on the symptoms and try until the problem disappears. Most likely, you see this approach when visiting your family physician.
Scientist approach: Why did the cooling process stop in this particular case? Level of water exceeded the maximum level? Why? Why?... and Why? until the root-cause for this specific problem is identified and validated. In this approach, the particular problem is analyzed by using 5Whys or any other method to identify the root cause.Which approach is the best? It depends. While the physician approach might be faster to solve the problem, the scientist approach gives you the most about understanding the process.
If we see problems as opportunities to learn more about the process instead of just making them disappear, a scientist-like approach - or PDCA in lean terms - is required.In the eyes of a good sensei, when solving a problem, one will fail if learning did not happen whether or not the problem went away. "What did you learn from the problem?" is a common question of a good sensei would ask to ensure we have learn by using a scientist approach