COSS Accident Investigation Principles 3 — Questions and Answers
Question 1: The 'Swiss Cheese Model' of accident causation, developed by James Reason, illustrates that accidents occur when:
- A single catastrophic failure overwhelms all safety systems
- Holes in multiple defensive layers align, allowing a hazard to reach a victim (Correct answer)
- Workers ignore established safety procedures repeatedly
- Equipment exceeds its rated capacity under normal use
Correct answer: Holes in multiple defensive layers align, allowing a hazard to reach a victim
Reason's Swiss Cheese Model shows that accidents occur when holes (failures) in multiple defensive layers temporarily align, creating an unobstructed path from hazard to harm.
Question 2: Which of the following is an example of a 'latent condition' in an accident investigation?
- A worker slipping on a wet floor
- A machine guard that was removed and never replaced months before an injury (Correct answer)
- Inadequate lighting directly at the accident scene
- A chemical spill that immediately caused skin burns
Correct answer: A machine guard that was removed and never replaced months before an injury
A latent condition is a pre-existing, dormant weakness (like a long-removed guard) that lies hidden until it combines with other factors to cause an accident.
Question 3: After completing an accident investigation, which action BEST ensures that corrective measures are actually implemented?
- Filing the investigation report in the safety records archive
- Establishing a tracking system with assigned responsibilities and due dates (Correct answer)
- Posting the investigation summary on the company bulletin board
- Conducting a single safety meeting to discuss findings
Correct answer: Establishing a tracking system with assigned responsibilities and due dates
A tracking system with assigned owners and due dates ensures accountability and verifies that recommended corrective actions are completed rather than left undone.
Question 4: When interviewing multiple witnesses to the same accident, an investigator discovers conflicting accounts. The BEST approach is to:
- Accept the account of the most senior employee as authoritative
- Triangulate accounts with physical evidence and documented facts to determine what occurred (Correct answer)
- Discard all witness testimony and rely only on physical evidence
- Report the conflict to management and end the investigation
Correct answer: Triangulate accounts with physical evidence and documented facts to determine what occurred
Investigators should triangulate conflicting witness accounts with physical evidence and documented facts to construct the most accurate picture of what occurred.
Question 5: Which of the following root cause categories is addressed when an investigator finds that a new employee was never trained on a hazardous procedure?
- Engineering failure
- Management system failure (Correct answer)
- Equipment malfunction
- Environmental hazard
Correct answer: Management system failure
Failure to provide required training is a management system failure, reflecting a breakdown in the organization's procedures for onboarding and hazard communication.
Question 6: A company consistently has high accident rates despite investigating each incident individually. This pattern MOST likely indicates:
- Bad luck affecting the facility
- A systemic management system failure not identified by single-incident analysis (Correct answer)
- Workers who are inherently careless
- Inadequate personal protective equipment selection
Correct answer: A systemic management system failure not identified by single-incident analysis
Persistently high accident rates despite individual investigations suggest systemic management system failures that single-incident RCA misses — trend analysis and systemic review are needed.
Question 7: The 'change analysis' method of accident investigation focuses primarily on:
- Identifying what changed from the normal, intended condition prior to the accident (Correct answer)
- Documenting how the organization's safety budget changed over time
- Analyzing workforce demographic changes that correlate with accidents
- Reviewing changes in OSHA regulations applicable to the facility
Correct answer: Identifying what changed from the normal, intended condition prior to the accident
Change analysis systematically compares what existed and how things were done before the accident versus the changed conditions or actions that occurred, identifying deviations that contributed to the event.
COSS Accident Investigation Principles 3
The 'Swiss Cheese Model' of accident causation, developed by James Reason, illustrates that accidents occur when: