Lessons Learned – How to Make Them Stick

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Incidents that happened before happen again, showing that we either are not paying attention to incidents or are not learning the lessons from those incidents.  On October 1989, Phillips 66 experienced a major explosion at its Pasadena, Texas, facility which killed 23 people and left more than a 100 injured.  This explosion precipitated the enactment of OSHA’s PSM Standard, 29 CFR 1910.119.  Among the causes of the incident, OSHA cited faulty maintenance procedures.  Ten years later, in 1999, an explosion rocked the same Pasadena facility resulting in two fatalities.  And a year later (2000) another explosion occurred in the same facility resulting in one fatality and 71 injured.  Although the immediate causes for all these explosions were different, the common thread was maintenance operations.  In another case, at Hoeganaes Corporation there wasn’t even a significant time span before incidents were repeated.  In 2011 the company experienced three incidents with a total of 4 fatalities and one serious injury.  All three incidents were related to a dust fire or explosion.  A recent editorial in Process Safety Progress shows examples and reiterates that we don’t seem to learn from past history.

Why Are Lessons Not Learned?

Lessons are not learned, not because of lack of trying.  The Global Congress on Process Safety (AIChE) which meets once a year, has a joint session of all its tracks dedicated to lessons learned.  CCPS has published books and maintains a database of incidents for participating companies.  In the last twenty years 297 articles on lessons learned have been published in Process Safety Progress, and articles continue to be published elsewhere.  A monthly bulletin from AIChE provides an account of an incident or near miss from which we can learn.  The US Chemical Safety Board (CSB) publishes online reports of its investigations and offers videos that demonstrate how the incident happened.

Companies typically circulate to employees the results of their own incident investigations and the reports are usually available internally.  But the lessons from those incidents may get lost, maybe because they don’t have immediate impact, or because they get forgotten when they should be applied, during process design or a process hazards analysis (PHA).

In essence, in spite of the wealth of incident information, the task of distilling a lesson from an incident, communicating it, and having people remember it when it’s needed, is a difficult task.  Typically, in the long term we retain about 10% of the information we receive during training.  And training is much more than sharing information where retention may be less than 2%.

How to Make Lessons Learned Stick

In order to really learn a lesson, the lesson needs to be delivered in a form that will be unforgettable, it needs to be woven into the fabric of the company, that is, translated into everyday use, and it needs to be periodically reinforced.

The Delivery of the Lesson

Studies have shown that long term retention of knowledge depends on the method of delivery of the training.  The amount retained can vary from 2% to 90% depending on whether the information was transmitted by reading, by oral presentation, visually, and/or by immediate application (the actual numbers have not been substantiated).  Presenting the information in an impactful visual method will lead to be retained longer and the videos from the CSB are an excellent example.  In Figure 1, taken from one of the videos, we can see two workers that have collapsed and died inside a reactor that had been inerted with nitrogen.  The workers had finished the job when they discovered that a tape had been left inside the reactor.  One of the workers tried to fish the tape with a wire while sitting in the open manhole.  He was overcome by the nitrogen and fell into the reactor where he collapsed from the nitrogen atmosphere.  When seeing this, his fellow worker tried to rescue him by inserting a ladder into the reactor and lowering himself into it.  He also collapsed.  This was noticed by a supervisor, but by the time that the proper equipment had been obtained for a rescue, the workers had died.  Showing the video will have much more impact than giving a lecture.  It is very important, though, to provide the correct lessons learned from the incident, adhering to the top two or three.  In this case they would be that (1) nitrogen is an insidious killer, and (2) do not attempt to rescue a fellow worker without first ensuring that you have the proper equipment to do so.

Figure 1.  Collapse of two workers in a nitrogen atmosphere (from the CSB video).

Integration into the Company’s memory  

If the lesson is well delivered but not applied, it may stay in people’s memory but it won’t be practiced and the value of the lesson will be lost.  Thus, the lesson needs to be integrated into the practices of the company.  A repository to capture the lesson is necessary and its essence applied to the company’s technical, operational and safety procedures.  

Reinforcing the Learnings

In spite of everything, memory fades with time.  Also, there’s turnover in the plant, new technologies are adopted, and procedures evolve.  There needs to be periodic reinforcement of the lessons learned in terms of the rationale for doing things the way there are being done.  Two ways of doing this reinforcement are:


By using the methods described here, lessons are learned through visualization, constant application and reinforcement.  Since the lessons become part of the knowledge of the company, and are integrated into its everyday activities which should include periodic refreshing, these lessons will stick.

A full article on the subject appears in: Chosnek J. Lessons learned—How to make them stick. Proc Safety Prog. 2020; e12198, https://doi.org/10.1002/prs.12198.

The pre-peer reviewed paper can be downloaded at http://knowledge1.net/publications/

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