Which sequence correctly outlines the steps of a root cause analysis when a machine won't start?

• A. Define problem, collect data, establish symptoms, develop hypotheses, test and verify, implement fix, confirm resolution, document results.
• B. Define problem, collect data, establish symptoms, test and verify, develop hypotheses, implement fix, confirm resolution, document results.
• C. Collect data, define problem, establish symptoms, develop hypotheses, test and verify, implement fix, confirm resolution, document results.
• D. Collect data, define problem, test and verify, establish symptoms, develop hypotheses, implement fix, confirm resolution, document results.

Answer: (A)

When diagnosing a machine that won’t start, the steps follow a logical flow: clearly state the problem to set the scope, gather relevant information, note what is observed as symptoms, form plausible root-cause hypotheses, test those hypotheses to confirm or refute them, implement the corrective fix, verify the problem is resolved, and finally document what was learned.

This sequence is why the best option begins with defining the problem, then collecting data, then establishing symptoms, followed by developing hypotheses, then testing and verifying, then implementing the fix, confirming resolution, and documenting results. Defining the problem first prevents scope creep and ensures you’re chasing the actual issue. Collecting data after that provides objective information to describe the situation without guessing. Recording symptoms clarifies what’s happening and aids in formulating testable hypotheses. Only after you have hypotheses should you test and verify, so you don’t waste time or introduce unnecessary fixes. Implementing the fix and then confirming the machine starts as expected closes the loop, and documenting results helps prevent recurrence.

Other sequences either test before forming hypotheses or start data collection before the problem is clearly defined, which can lead to chasing symptoms rather than the root cause.