Identifying Causes of Accidents

1. Identifying Causes of Accidents • Surface vs. Root Causes • Surface causes are: • the hazardous conditions or unsafe work practices that directly or indirectly contributed to the accident. • Root causes are: • the safety or loss control system weaknesses that allow the existence of hazardous conditions and unsafe work practices. • Most accident investigations only identify the surface causes of accidents.

2. Events and Causal Factor Analysis • Events and Causal Factor Analysis identifies the time sequence of a series of tasks and/or actions and the surrounding conditions leading to an occurrence. • The results are displayed in an Events and Causal Factor chart that gives a picture of the relationships of the events and causal factors.

3. Change Analysis • Change Analysis is used when the problem is obscure. • It is a systematic process that is generally used for a single occurrence and focuses on elements that have changed.

4. Barrier Analysis • Barrier Analysis is a systematic process that can be used to identify physical, administrative, and procedural barriers or controls that should have prevented the occurrence.

5. Management oversight and Risk Tree (MORT) Analysis • MORT and Mini-MORT are used to identify inadequacies in barriers/controls, specific barrier and support functions, and management functions. • It identifies specific factors relating to an occurrence and identifies the management factors that permitted these factors to exist.

6. Human Performance Evaluation • Human Performance Evaluation identifies those factors that influence task performance. • The focus of this analysis method is on operability, work environment, and management factors. • Man-machine interface studies to improve performance take precedence over disciplinary measures.

7. Kepner-Tregoe Problem Solving and Decision Making • Kepner-Tregoe is a management consulting firm • Kepner-Tregoe provides a systematic framework for gathering, organizing, and evaluating information and applies to all phases of the occurrence investigation process. • Phases: • Situation appraisal: Identify concerns • Problem analysis: Define the problem (Similar to Change Analysis) • Decision Analysis: Evaluate alternatives, assess risks • Potential Problem Analysis: What new problems may be introduced by the alternatives?

8. Accident Investigation Process • The accident investigation process involves the following steps: • Report the accident occurrence to a designated person within the organization • Provide first aid and medical care to injured person(s) and prevent further injuries or damage • Investigate the accident • Identify the causes • Report the findings • Develop a plan for corrective action • Implement the plan • Evaluate the effectiveness of the corrective action • Make changes for continuous improvement

9. Retrospective Investigations • Retrospective investigations are accident investigations that look back in time at a situation. Most investigations conducted in the workplace can be classified as a retrospective investigation.

10. Statistical Investigations • Statistical investigations utilize data collected over a period of time to determine causes and develop prevention measures. • Statistical investigations utilize mathematical techniques that identify the causes for accidents in terms of statistical probabilities.

11. Large Loss Investigations • Large loss investigations are considered in-depth investigations directed at an accident that resulted in a larger than usual loss of life, money, or property damage. • Examples of large loss investigations include large industrial fires, plant explosions, and airplane crashes

12. Systems Investigations • Systems investigations utilize a systems approach to the identification of causal factors. • There are a variety of systems investigation techniques available including root cause analysis, Fault Tree Analysis (FTA), and Failure Modes and Effects analysis (FMEA).