Incident investigations are a necessary component of any organization’s environmental, health and safety (EHS) program. Effective incident investigation will not only identify, document, and analyze an event, but will also help to identify the root causes to mitigate and avoid future incidents.

This blog series is dedicated for those searching for an incident investigation methodology, and answers the many questions an investigator might have when evaluating methodologies and tools.

The Need for a Methodology 

One fascinating yet troubling phenomenon that often goes unnoticed during incident investigations is that individual beliefs play a major determining role in the outcome, because those outcomes depend partly on where the investigators believe the root cause lies. This includes opinions and assumptions the investigator has at the beginning along with prejudices formed along the way. It goes even deeper than individual beliefs about how accidents happen, however. Even experienced and well-trained safety professionals sometimes are biased in that they support causation models which may not tell the full story of how incidents came about.

Frequently, an investigation team’s bias can result in narrowly-focused cause analysis. This shortcoming can result in avenues of investigation being left unexplored, which can happen when investigation teams are influenced by their preconceived notions, or jump to conclusions.

Rarely is a single factor to blame in isolation for an event that results in serious harm. An important lesson is that “disasters are very rarely the product of a single monumental blunder.”¹ Thorough root cause analysis often uncovers surprising results, which underscores the reason letting preconceived notions guide the process may result in never finding the real cause. Worse yet, failing to mitigate the actual root cause puts lives and assets at continued, preventable risk. Indeed, there’s prevailing and persistent misinformation in the industry, causing many EHS professionals to mismanage their incident investigation initiatives.

Getting Past Assumptions

Many practitioners are misguided by a persistent myth in the industry. The myth that’s persisted for at least half a century is that workers committing unsafe practices are the cause of most incidents in the workplace. It has been stated² that the causes of industrial accidents could be broken down in this way:

• 88% caused by “unsafe acts of persons”
• 10% caused by “unsafe mechanical or physical conditions”
• 2% unpreventable

Believe it or not, many of the incident investigations performed even today are permeated by this 88-10-2 formula. It’s still taught in educational programs at universities and is therefore extremely entrenched in the incident management community. Due to lack of knowledge and bad beliefs, many EHS professionals are not using effective causation models.

Driven by this type of formulaic belief system, which does not take into account everything cause analysis research has taught us in the past few decades, investigative teams start out with the belief that the cause of incidents will be the people at the bottom of the management chain: the operators. That means first-line employees (“operators”) are preconceived to be the cause of incidents, whereas the actual cause is more complex (and systemic) than that. It usually lies in a series of events and conditions.

The persistence of this type of misconception is one of the major reasons why companies find a rigorous incident investigation methodology to be an incredibly helpful and powerful addition to their EHS program. A well-defined investigation methodology assists investigators in finding the actual root causes so long term solutions can be implemented.

In part two of this four-part blog series, we'll cover the different models and methodologies—from logical tree and systemic to EHS and process-driven models—to help you make better investigative decisions.

1 - Reason, J. T. Human Error. Cambridge: Cambridge UP, 1990
2 - Manuele, Fred A. On the Practice of Safety. Wiley Publishers, 2003

Related Resources:

Incident Investigation Blog Series – Part 2: Methodologies and Models

8 Investigation Methodologies to Uncover Root Causes