sharif university of technology industrial engineering Safety at

sharif university of technology industrial engineering Safety at work (Accident Investigation) Razieh shoeleh Roya mohamad ali poor fall 2006

What is Ergonomics?

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.

Accident Investigation

• 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)

The accident investigation process

Three phases in accident investigation

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

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

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.

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

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

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

Diagram Tripod_beta Elements • Event • Hazard • Target

Hazard conduct

TRIPOD Beta accident causation model

Example on a TRIPOD Beta analysis

Thanks for your attention