Accident and Incident Investigation: Criteria to Achieve the Goals

Thousands of accidents occur in workplaces across the world every day. The failure of people, equipment, supplies, or surroundings to behave or react as expected contribute to most of the accidents. The aim of accident investigations is to determine how and why contributing failures occur. Managers and other decision makers can, by making use of the information gained through appropriate investigations, prevent a similar or perhaps more disastrous accident to take place. Conducting accident investigations with accident prevention in mind is the key to making a significant contribution towards workplace safety. In cases where accident or incident investigations are done in order to apportion blame the investigation normally fails to make any meaningful contribution to the improvement of safety in the workplace.

Goals of the Investigation

Where possible, the investigator should be free of the operational influence of the employees concerned, in order that the investigation may be objective. The investigation should be a thorough attempt to identify fundamental contributing factors. The tendency to blame an accident on any employee's carelessness should be avoided because the term is too vague and usually hides all the other problems that could be corrected, if identified. More often than not, it is easier to rectify problems in other areas, in the short term, and to address behavioural changes in workers over a longer period.

It has been established that accidents are the result of the contact of a person or piece of equipment with energy (mechanical, electrical, thermal, etc.) or hazardous material (carbon monoxide, dust, water, etc.) that exceeds the threshold limit and results in injury, property damage and/or equipment failure.

During an investigation the investigator should determine the fundamental contributing factors to the accident by first establishing what happened, why it happened and how the contributing factors of the accident each contributed. The outcome of a good investigation should include the assignment of persons to implementing preventative actions based on the outcome of the investigation.

In order to investigate accidents successfully it is required to understand the elements involved in an accident. Usually, an accident is the result of multiple elements acting together. Based on research, the investigation model that is normally best suited for the conducting of efficient accident investigations are those based on multi dimensional factors that focuses on the fundamentals.

Decision to Investigate

It will generally not be possible to conduct a detailed investigation into every accident that occurs in a workplace. The decision on the level of detail of an investigation should be based on objective criteria. One such method is the risk profile associated with the accident or group of accidents.

Marx et al (1996) identify four general levels of ranking risk as follows:

• High risk
• Moderately high risk
• Moderately low risk
• Low risk

This is described as a rough assessment of the risk profile but can be sufficient if it is conducted utilizing objective and repeatable criteria.

If the criteria includes taking into account the consequence potential, the frequency of occurrence and the exposure of the workforce to the hazard that resulted in the accident, the risk assessment used to determine the risk category of the accident would be deemed to be suitable and sufficient.

A number of alternative approaches for the measurement of risk are available. The most commonly used method is a risk matrix approach. In using this approach the investigator should categorize the consequences of the hazard and its frequency separately and then combine these in a matrix to determine the risk ranking.

Conclusion

The investigator should take the resulting risk category into account when deciding on the level of the investigation to be arranged, as well as the size and composition of the investigation team, in respect of any accident.

It is normal practice for each individual company to develop a tolerability index. This implies that only accidents with a risk ranking higher than the tolerability level for that mine will be investigated. The decision whether to investigate or not should also take cognizance of accident trends on a particular site, as well as recent accidents which invoked exceptional public interest.

©Carl Marx 2009