Which of the following is commonly used as a root cause analysis technique in incident investigations?

• A. Hazard and operability study
• B. 5 Whys
• C. Routine inspection
• D. Emergency drills

Answer: (B)

When digging into why an incident happened, a simple, practical way to reach the underlying causes is to repeatedly ask why. The 5 Whys method does just that: start with the incident, ask why it occurred, then take the answer and ask why again, continuing until you reach a root cause that actions can address. It’s favored because it is quick, inexpensive, and doesn’t require advanced tools or data, yet it helps uncover deeper issues such as gaps in procedures, training, or management practices that allowed the incident to occur.

Other options aren’t used as root-cause analysis techniques in investigations. A hazard and operability study looks forward, identifying potential hazards in a process before incidents happen. Routine inspections are about checking equipment or conditions for standard issues, not analyzing a past incident and its causes. Emergency drills test response readiness rather than diagnosing why an incident happened.