Incident Investigation, Lessons Learned, and Continuous Improvement
This domain tests whether you can investigate an event without blame, separate immediate from systemic causes, and drive corrective actions that actually prevent recurrence.
Investigation method
Preserve the scene and evidence, secure records, interview witnesses separately, and build a timeline. Identify immediate causes, contributing factors, and root or organizational causes. Methods include 5 Whys, fishbone diagrams, barrier analysis, change analysis, and events and causal factors charts. Barrier analysis asks which controls failed, were missing, or were bypassed. Just culture distinguishes human error, at-risk behavior, and reckless conduct so that reporting is not discouraged.
Corrective action and learning
Corrective actions should follow the hierarchy of controls, be specific, and have an owner, due date, and verification of effectiveness. Lessons learned must be disseminated and fed back into hazard logs, procedures, training, design standards, and audit schedules. Track recurrence and closure quality, not just the number of actions completed.
Worked example
The same pump seal fails twice. The first investigation recommends “retrain operators.” The better analysis examines seal specification, installation, spare-parts control, and alignment. Barrier analysis shows that receiving inspection and installation verification were missing. Corrective actions should include a part-number check at receiving, a verified installation procedure, and an audit after six months. Reasoning: retraining does not address the physical and organizational conditions that produced the repeat failure, and effectiveness must be checked.
Traps that cost marks
- Stopping at “operator error” or “procedure not followed.”
- Recommendations with no owner, date, or evidence of completion.
- Assuming training fixes a design or supply-chain problem.
- Closing actions without verifying effectiveness or checking recurrence.