Incident Investigation 1: Definitions, Purpose and Selecting the Investigation Level
Scope of this domain
Domain 1 of 4 tests whether you can define an incident, justify investigating it and select a proportionate investigation level.
Core rules
- Incident: an undesired event that caused or could have caused harm. An accident produced actual loss; a near miss did not. A dangerous occurrence is a specified high-potential event reportable even without injury.
- Purposes: prevent recurrence, meet legal duties, record facts, detect trends, learn, and supply evidence to insurers or regulators.
- Investigate on potential severity, not just actual harm: a near miss that could have killed someone merits a full investigation. This is the practical use of the accident-triangle idea.
- A written procedure should define levels of investigation, from a supervisor's short enquiry into a minor event to a team-based formal investigation of a fatality.
- Investigators must be competent and, where practicable, independent of the event; supervisors, safety advisers, engineers and specialists may all contribute.
- Start promptly to secure evidence, but do not disturb the scene before casualties are safe and the scene is recorded.
Worked example
A 20 kg box falls from a mezzanine rack and lands half a metre from a pedestrian. Nobody is hurt, so no entry is made and nothing is investigated. That is wrong. Actual severity was nil but potential severity was fatal, so the procedure should classify it as high-potential, trigger a team investigation and ask why the box was unsecured, why the rack had no edge protection and why the near miss went unreported.
Traps
Treating accidents and near misses as unrelated; investigating only reportable events; over-investigating trivia; letting the line manager in charge of the activity run the whole investigation unsupervised.