9. sharif university of technology industrial engineering Safety at work
(Accident Investigation)
Razieh shoeleh
Roya mohamad ali poor
fall2006

10. What is Ergonomics?

11. What is an Accident?
A sequence of logically and chronologically related deviating events involving an incident that results in injury to personnel or damage to the environment or material assets.

12. Accident Investigation

13. The purpose of accident investigation
Identify and describe the true course of events (what, where,when)
Identify the direct and root causes / contributing factors of the accident (why)
Identify risk reducing measures to prevent future, comparable accidents (learning)
Investigate and evaluate the basis for potential criminal prosecution (blame)
Evaluate the question of guilt in order to assess the liability for compensation (pay)

14. The accident investigation process

16. Three phases in accident investigation

17. Collecting evidence and facts
Human or testamentary evidence
Human or testamentary evidence includes witness statements and observations.
Physical evidence
Physical evidence is matter related to the accident (e.g. equipment, parts, debris, hardware, and other physical items).
Documentary evidence
Documentary evidence includes paper and electronic information, such as records, reports, procedures, and documentation.

18. Analysis of evidence and facts
What happened where and when?
Why did it happen?
types of causal factors:
Direct cause
Contributing causes
Root causes

19. Recommendations and reporting
Hendrick and Benner (1987) says that two thoughts should be kept in mind regarding accident reports:
Investigations are remembered trough their reports
The best investigation will be wasted by a poor report.

20. Methods for accident investigation
TRIPOD
Barrier analysis
Change analysis.
Events and causal factors analysis

21. OTHER ACCIDENT INVESTIGATION METHODS
Fault tree analysis
Root cause analysis
Events and causal factors charting (ECFC)
Event tree analysis
MORT
Systematic Cause Analysis Technique (SCAT)
(Sequential timed events plotting)
MTO-analysis
Accident Analysis and Barrier Function (AEB) Method
Acci-map

22. TRIPOD _BETA Definition Advantages Phases: Diagram Tripod_beta
Hazard conduct
accident causation model

23. Diagram Tripod_beta
Elements
Event
Hazard
Target

24. Hazard conduct

25. TRIPOD Beta accident causation model

26. Example on a TRIPOD Beta analysis

28. Thanks for your attention