2.4 Analysis
Once facts are collected, they need to be analysed to help establish the sequence of events in the occurrence, and to draw conclusions about safety deficiencies uncovered by the investigation. Analysis is a disciplined activity that employs logic and reasoning to build a bridge between the factual information and the conclusions.
The first step in analysis is to review the factual information to clarify what is relevant and what is not, and to ensure the information is complete. This process can give guidance to the investigator as to what additional investigation needs to be carried out.
In normal investigation practice, gaps in information that cannot be resolved are usually filled in by logical extrapolation and reasonable assumptions. Such extrapolation and assumptions should be identified and a statement of the measure of certainty provided.
Despite best efforts, analysis may not lead to firm conclusions. In these cases, the more likely hypotheses should be presented.
2.4.1 Fact-finding and analysis
After fact-finding and analysis it should be possible to give a description of the occurrence, its background, the time it took place, and the events leading to it.
The description should include such factual items as:
- the weather conditions;
- the operation(s) involved;
- the equipment in use, its capabilities, performance and any failures;
- the location of key personnel and their actions immediately before the incident;
- the pertinent regulations and instructions;
- uncontrolled hazards;
- changes of staff, procedures, equipment or processes that could have contributed to the occurrence;
- what safeguards were or were not in place to prevent the Incident;
- response to the occurrence (first-aid, shut-down, fire-fighting, evacuation, search and rescue);
- medical treatment actions taken to mitigate the effects of the occurrence and the condition of injured parties, particularly if disabling injuries or death ensued;
