Chasing Numbers: The Folly of TRIR Obsession

Chasing Numbers: The Folly of TRIR Obsession

By Josh Williams, Ph.D.

Safety leadership can be tricky. Smart leaders regularly review safety incidents as an opportunity to make process and system improvements for future prevention. Staying on top of incident trends is smart business. However, there seems to be a growing obsession with TRIR rates among North American organizations. Almost without fail, leaders will provide us detailed descriptions of monthly incident rate fluctuations. In fact, we are often contacted because of recent spikes in recordables.

Here’s the problem. There is natural variation in incident occurrence.

For instance, you may be managing safety poorly but still have reasonable outcome numbers for a given time period. This leads to a false sense of security. Conversely, you may be doing most everything right for safety but still have a few recordables “pop up.” Recently, an HSE person lamented that an office employee sprained her ankle (recordable!) in the parking lot walking into work. A few other similar incidents occurred during this timeframe (after many months with no issues) and executives started to take notice. Incidents are bad for business and often impact executive bonuses. Pressure to reverse this trend began cascading down the organization.

The desire to prevent future incidents is commendable, but problems arise when there are overreactions to short-term TRIR increases, including:

  1. Front-line leaders are scared to lose their jobs if someone else gets hurt.
  2. Employees are more likely to be blamed when incidents do occur.
  3. Fear of reporting increases drives incident (and close call) reporting underground.

On top of that, new research shows a negative correlation between incident rates and fatalities.

Focusing on TRIRs and LTIs without sufficient focus on SIF potential can be misleading and dangerous. For example:

  • “A study of Finnish construction and manufacturing from 1977 to 1991 showed a strong negative correlation between incident rate and fatalities (r =.82, p<0.001). In other words, the fewer incidents a construction site reported, the higher its fatality rate was (Saloniemi and Oksanen, 1998). This replicates findings from aviation on the same negative correlation: passenger deaths were actually higher on airlines that reported fewer incidents (Barnett and Wang, 2000).” (Dekker 2014)
  • In 1998, an explosion at ESSO Australia killed two people and injured eight more. Complacency may have set in since they had no LTIs the previous year, won an industry safety award, and went 5 million work hours without an LTI. As Hopkins (2001) notes, “LTI data are thus a measure of how well a company is managing the minor hazards which result in routine injuries; they tell us nothing about how well major hazards are being managed…thus a focus on LTIs can lead companies to become complacent about their management of major hazards. This is exactly what seems to have happened at Esso.”
  • “Total recordable incident rates and lost time incident rates do not effectively predict a facility’s risk for a catastrophic event. (CSB, 2007, p. 202). Another such case seems to be the 2010 Macondo (or Deepwater Horizon) well blowout in the Gulf of Mexico, which killed 11 people and caused the biggest oil spill in the history of humanity. It was preceded by a celebrated six years of injury-free and incident-free performance on the platform (or boat, really)” (Dekker 2017).

Make no mistake. Reviewing all incidents with an eye on future prevention is critical. And TRIR and LTI rates do matter. However, fixating on these injury statistics without a broader focus on SIF potential is counterproductive and dangerous. The error precursors influencing typical injuries are often different than those contributing to serious injuries and fatalities. So, keep your eye on the prize with injury numbers but don’t get seduced into TRIR fluctuation obsession. 

At Propulo, we work with leaders to more intelligently manage leading and lagging safety metrics with a focus on SIF prevention.     


Dekker, S. (2014): The Bureaucratization of Safety, Safety Science, 70(2014), 348-357.

Dekker, S. (2017): Zero commitment: commentary on Zwetsloot et al., and Sherratt and Dainty, Policy and Practice in Health and Safety, DOI.

Hopkins, A. (2001). Lessons from Esso’s gas plant explosion at Longford. Canberra, Australia: Australian National University.


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