What is a 5 Whys technique and give an example scenario in manufacturing.

What is a 5 Whys technique and give an example scenario in manufacturing.

• A. A root-cause analysis method that asks 'Why?' repeatedly to trace to the fundamental cause of a problem.
• B. A statistical method to compare means.
• C. A method to design experiments.
• D. A technique for final inspection.

Answer: (A)

The 5 Whys technique is a simple root-cause analysis method that reveals the fundamental cause of a problem by asking “Why?” and answering that question in successive steps until you reach a cause that, if fixed, would prevent recurrence. Example in manufacturing: a part fails a tolerancing check on the line. Why is it out of spec? Because the hole diameter is undersized. Why is it undersized? Because the drill bit used on that station has worn down. Why has it worn down? Because there’s no routine for monitoring tool wear and timely replacement. Why is there no routine? Because the maintenance schedule doesn’t include tool-life tracking. The root cause is the lack of a tool-life monitoring and preventive maintenance process for cutting tools. Addressing this by implementing tool-life monitoring, setting replacement thresholds, and training operators to report wear would prevent the issue from recurring. This approach isn’t about statistics or comparing means, nor is it about designing experiments or performing a final inspection; it’s about drilling down to what, in worst-case, allowed the problem to occur so you can fix the underlying system.

The 5 Whys technique is a simple root-cause analysis method that reveals the fundamental cause of a problem by asking “Why?” and answering that question in successive steps until you reach a cause that, if fixed, would prevent recurrence.

Example in manufacturing: a part fails a tolerancing check on the line. Why is it out of spec? Because the hole diameter is undersized. Why is it undersized? Because the drill bit used on that station has worn down. Why has it worn down? Because there’s no routine for monitoring tool wear and timely replacement. Why is there no routine? Because the maintenance schedule doesn’t include tool-life tracking. The root cause is the lack of a tool-life monitoring and preventive maintenance process for cutting tools. Addressing this by implementing tool-life monitoring, setting replacement thresholds, and training operators to report wear would prevent the issue from recurring.

This approach isn’t about statistics or comparing means, nor is it about designing experiments or performing a final inspection; it’s about drilling down to what, in worst-case, allowed the problem to occur so you can fix the underlying system.