The "5 Whys" is a problem-solving methodology that focuses on identifying the root cause of an issue by asking "Why?" repeatedly until the underlying problem is identified. It is a straightforward technique developed by Sakichi Toyoda and was later integrated into the Toyota Production System. Although it's called the "5 Whys," it's not strictly limited to five questions; you keep asking "Why?" until you reach the root cause.

Procedure

• State the problem clearly.
• Ask "Why did this problem occur?"
• Based on the answer to the first "Why?", ask "Why?" again.
• Continue the process until you identify the root cause of the problem.
• Once the root cause is identified, implement corrective actions to prevent the problem from recurring.

Example of an organization's server unexpectedly shuts down

Problem: The server shut down unexpectedly.

• Why? The server overheated.
• Why did the server overheat? The cooling system failed.
• Why did the cooling system fail? The air filters were clogged with dust.
• Why were the air filters clogged with dust? They hadn't been cleaned or replaced in over a year.
• Why hadn't they been cleaned or replaced? There was no scheduled maintenance or reminder system in place.