Heinrich's Triangle Explained

Introduction to Heinrich's Triangle
In this article the Heinrich's Triangle theory of that defines the ration between accidents and incidents of differing severity will be discussed with a view of evaluating and extracting the benefits that this theory can add to an improved safety environment in companies.

The Heinrich's Triangle
According to Heinrich, (1930), a well-managed loss control strategy provides an operational strategy that contributes to the improvement of overall management. While Heinrich's triangle is illustrative of the ratio of types of accidents, it implies that the same contributing factors are at work throughout the triangle. Of course, this cannot be the case. Despite being a groundbreaking publication for the era, the basic approach has many flaws and cannot be implemented without major changes.

The triangle clearly indicates that a very specific ratio exists between various levels of severity. This can be very useful when analysing accidents, however, it does not provide any failure modes that may be utilised during pro-active prevention activities.

Later studies by other researchers found that a specific ratio does exist but that the ratio is different for different industries or even industry sectors. These findings make sense if one considers that the risk profile is different in different industries and certain industry sectors.

In the figure of the Heinrich's Triangle that can be viewed herethe figuregraphically illustrates the ratio between various levels of accident and incident severity. The figure is in the form of a pyramid with horizontal sectors running across. It clearly indicates that every serious or major injury is preceded by ten minor injuries and thirty property damage accidents. Heinrich established no explanation of the reasons for the accidents, and therefore this cannot be viewed as a formal investigation method. The ratios established does however provide invaluable information to investigators regarding accidents that may be unreported.

The theory is that for every 1 serious or major injury that results for a workplace accident there should be ten minor injuries reported. The theory goes further that for every 10 minor injuries these should be 30 incidents occurring that does not result in injuries but do result in property damage. The final part of the theory is that for every 30 property damage incidents there will be 600 workplace accidents or incidents with no visible injury or damage. These workplace accidents or incidents with no visible injury or damage are also sometimes referred to as "near miss" incidents.

Conclusion

Some safety professionals do not agree with the term near miss as it implies that it was hit. Irrespective of the term used the fact of the matter is that these ratios exist and can be used to establish whether the reporting regime of a company is consistent and reliable. If major deviations are found over time and between sites with similar risk profiles safety professionals should investigate the reporting culture, system and structure to eliminate major discrepancies.

© 2009 Carl Marx