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).

13. Human Error and Accident Management • Human Error and Accident Management offers means and ways to recognize and prevent these behaviors. • Provides for a means to control and recover from these behaviors when they do occur and to contain and escape from their adverse.

14. Accidents and Human Errors • Human error is the cause of accidents • To explain a failure, you look for a failure • You must find people's inaccurate assessments, wrong decisions, and bad judgments • Human error is a symptom of trouble deeper inside a system • To explain failure, do not try to find where people went wrong • Instead, find how people's assessments and actions made sense at the time, given the circumstances that surrounded them

15. Types of Human Errors • Random versus Systemic Errors • What’s the difference? • Is one type easier to control than the other?

16. Active Errors • Active errors become very visible in the evolution of an event. • The active errors are also the most obvious occurrences and the most rapidly identified human contributors in an accident.

17. Latent Errors • The higher in the organization these latent errors are made, the more serious the consequences at the front line operation. • Latent errors of strategic nature, such as defining company policies affect safety attitudes and the safety culture in the organization. • The most serious and dangerous errors to be tackled.

18. Accident Investigation Process • What are some ways you as an investigator can identify human errors as they contribute to the accident sequence? • Are human errors the root causes for accidents? • Why or why not?

19. Human Error and Accident Investigations • As an accident investigator, what role does your knowledge about human error play in your investigation process?

20. Questions for probing the reasons for events that appear to be caused by human error • Was the possibility of the error known? * • Were the potential consequences of the error known? * • What about the activity made it prone to the occurrence of the error? • What about the situation contributed to the creation of the error? • Was there an opportunity to prevent the error prior to it's occurrence? * • Once the error was committed, was there any way to recover from it? * • What about the system sustained the error instead of terminating it? • What fed the error, and drove it to become a bigger problem? • What made the consequences as bad as they were? • What (if anything) kept the consequences from being worse? • * If YES, why did the event proceed beyond this point? If NO, why not?