The Heinrich Accident Triangle—Too Simplistic A Model for HSE Management in the 21st Century?

Abstract

The accident triangle, developed by H.W. Heinrich in the 1930s, is a fundamental cornerstone of safety philosophy which postulates that there is a numerical relationship between unsafe acts, minor injuries, and major (fatal) injuries. This principle has driven the approach and techniques used by all companies actively engaged in reducing injuries in the workforce for over 70 years.All companies in the oil and gas industry have the ultimate goal of zero injuries and, in particular, zero fatal injuries within their workforce. Current injury trends show that the total recordable injury rate (TRIR) for a given company can still be systematically reduced year on year if the right commitment and focus is given to safety. This does not hold true in many cases for the fatal accident rate (FAR) which often no longer mirrors the TRIR trend as one would intuitively expect. This begs an answer to the question of whether the tools and methods used to reduce fatalities are still working. This paper demonstrates that Heinrich's principle works only when applied to a large number of combined hazards and activities. The paper shows that ratios postulated by Heinrich do not work when applied to specific activities. The result is that companies tend to over focus on the easily identifiable risks which follow the Heinrich triangle but are often nonfatal, at the cost of losing sight of activities that have the potential of a fatal outcome.By drawing on the 2.3 million risk reports recorded in the health, safety, and environment (HSE) database of an oilfield services company, the paper also demonstrates the value of focusing on risk potential-rather than only on actual event outcomeas a key tool for minimizing catastrophic loss. It discusses strategies of how to specifically target and actively work on improving the FAR as opposed to the more general TRIR.

Workplace accidents and self-organized criticality

“…Heinrich's work has had an enormous influence on thinking around workplace safety for many decades, but recently it has been criticized by some as being "unscientific" [14]. For example, Anderson and Denkl have argued that Heinrich's Law only applies to aggregate data and not to individual activities and that separate efforts should be specifically devoted to high-risk activities [15]. Our results herein give scientific support to…”

Seismic exclusions and re-entry from a risk perspective

“…This is often justified by citing the Heinrich (or Bird) safety triangle; i.e. the premise that there is a stable ratio between the number of severe-rare and minor-frequent incidents but this notion has been broadly invalidated (Anderson & Denkl 2010;Gallivan et al 2008;Manuele 2011). Incidents that are high-frequency, low-severity constitute the majority of reported incident statistics and, therefore, naturally demand more focus from management.…”

A fuzzy logic evolution of the functional resonance analysis method (FRAM) to assess risk in ground operation

“…For the first phenomenon, accident triangle, developed by H.W. Heinrich in the 1930s, is one of the first studies in the literature (Anderson and Denkl, 2010). Incident trends and causes of the occurrences were investigated in detail to understand the interaction between minor and major events (Martin and Black, 2015).…”