May 14, 2018 | Ken Reed

“It was such a simple mistake!”











When you have a major incident (fire, environmental release, etc.), your investigation will most likely identify several causal factors (CF) that, if they had not occurred, we probably would not have had the incident.  They are often relatively straight forward, and TapRooT® does a great job identifying those CFs and subsequent root causes.

Sometimes, the simplest problems can be the most frustrating to analyze and fix.  We think to ourselves, “How could the employee have made such a simple mistake?  He just needs to be more careful!”  Luckily, TapRooT® can help even with these “simple” mistakes.

Let’s look at an example.  Let’s say you are out on a ship at sea.  The vessel takes a bit of a roll, and a door goes shut on one of your employees.  His finger is caught in the door as it shuts, causing an injury.  Simple problem, right?  Maybe the employee should just be more aware of where he is putting his hands!  We will probably need more effective fixes if we really want to prevent this in the future.

How can we use TapRooT® to figure this out?  First of all, it is important to fully document the accident using a SnapCharT®.  Don’t skip this just because you think that the problem is simple.  The SnapCharT® forces you to ask good questions and makes sure you aren’t missing anything.  The simple problem may have aspects that you would have missed without fully using this technique.  In this example, maybe you find that this door is different than other doors, which have latches to hold them open, or handles to make it easier to open the door.  Imagine that this door might have been a bathroom stall door.  It would probably be set up differently than doors / hatches in other parts of the ship.

So, what are your Causal Factors?  First, I probably would not consider the sudden movement of the ship as a CF.  Remember, the definition of a CF states that it is a mistake or an error that directly leads to the incident. In this case, I think that it is expected that a ship will pitch or roll while underway; therefore, this would not be a CF. It is just a fact. This would be similar to the case where, in Alaska, someone slipped on a snow-covered sidewalk. I would not list that “it was snowing” as a CF.  This is an expected event in Alaska. It would not be under Natural Disaster / Sabotage, either, since snow is something I should be able to reasonably protect against by design.

In this case, I would consider the pitch / roll of the vessel as a normal occurrence.  There is really nothing wrong with the vessel rolling. The only time this would be a problem is if we made some mistake that caused an excessive roll of the vessel, causing the door to unexpectedly slam shut in spite of our normal precautions. If that were the case, I might consider the rolling of the ship to be a CF.  That isn’t the case in this example.

You would probably want to look at 2 other items that come to mind:

1.  Why did the door go shut, in spite of the vessel operating normally?
If we are on a vessel that is expected to move, our doors should probably not be allowed to swing open and shut on their own. There should be latches / shock absorbers / catches that hold the door in position when not being operated. Also, while the door is actually being operated, there should be a mechanism that does not depend on the operator to hold it steady while using the door. I remember on my Navy vessel all of our large hatches had catches and mechanisms that held the doors in place, EXCEPT FOR ONE HEAVY HATCH. We used to tell everyone to “be careful with that hatch, because it could crush you if we take a roll.” We had several injuries to people going through that hatch in rough seas. Looking back on that, telling people to “be careful” was probably not a very strong safeguard.

Depending on what you find here, the root causes for this could possibly be found under Human Engineering, maybe “arrangement/placement”, “tools/instruments NI”, excessive lifting/force”, “controls NI”, etc.

2. Why did the employee have his hand in a place that could cause the door to catch his hand?
We should also take a look to understand why the employee had his hand on the door frame, allowing the door to catch his finger.  I am not advocating, “Tell the employee to be careful and do not put your hand in possible pinch points.” That will not work too well. However, you should take a look and see if we have sufficient ways of holding the door (does it have a conventional door knob? Is it like a conventional toilet stall, with no handle or method of holding the door, except on the edge?). We might also want to check to see if we had a slippery floor, causing the employee to hold on to the edge of the door / frame for support. Lots of possibilities here.

Another suggestion: Whenever I have what I consider a “simple” mistake that I just can’t seem to understand (“How did the worker just fall down the stairs!?”), I find that performing a Critical Human Action Profile (CHAP) can be helpful.  This tool helps me fully understand EXACTLY what was going on when the employee made a very simple yet significant mistake.

TapRooT® works really well when you are trying to understand “simple” mistakes.  It gets you beyond telling the employee to be more careful next time, and allows you to focus on more human performance-based root causes and corrective actions that are much more likely to prevent problems in the future.

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