Which root cause tool uses repeated 'why' questions to move from symptom to underlying cause?

Which root cause tool uses repeated 'why' questions to move from symptom to underlying cause?

• A. The Cause Tree
• B. The Five Whys
• C. Fishbone Diagram
• D. Fault Tree Analysis

Answer: (B)

The approach of drilling down to the underlying cause by asking why repeatedly is the Five Whys. It starts with the symptom and asks why it happened, then takes the answer and asks why that happened, continuing this cycle until you reach a cause that cannot be explained further by another why. This simple, iterative questioning helps uncover the root cause, especially for process issues or human factors, and it often reveals practical fixes that prevent recurrence. It’s valued for its speed, ease of use, and ability to foster team discussion without requiring complex data. Other tools take a different tack. A Cause Tree maps out possible causes in a branching structure to visualize relationships without relying on repeated why questions. A Fishbone Diagram organizes potential causes into categories like people, process, equipment, and materials to brainstorm factors, but it doesn’t hinge on the iterative why sequence. Fault Tree Analysis builds a formal logical diagram using gates to show how combinations of failures lead to the top event, focusing on probabilistic logic rather than a step-by-step why questioning.

The approach of drilling down to the underlying cause by asking why repeatedly is the Five Whys. It starts with the symptom and asks why it happened, then takes the answer and asks why that happened, continuing this cycle until you reach a cause that cannot be explained further by another why. This simple, iterative questioning helps uncover the root cause, especially for process issues or human factors, and it often reveals practical fixes that prevent recurrence. It’s valued for its speed, ease of use, and ability to foster team discussion without requiring complex data.

Other tools take a different tack. A Cause Tree maps out possible causes in a branching structure to visualize relationships without relying on repeated why questions. A Fishbone Diagram organizes potential causes into categories like people, process, equipment, and materials to brainstorm factors, but it doesn’t hinge on the iterative why sequence. Fault Tree Analysis builds a formal logical diagram using gates to show how combinations of failures lead to the top event, focusing on probabilistic logic rather than a step-by-step why questioning.