Phil says: In safety we are surrounded by people who are looking for simple solutions to complex problems and often these people include safety professionals themselves. In this months post I look at applying Occam’s Razor (The simplest explanation is usually the correct one) to incident investigation and find it lacking. I hope you will give it a read and tell me what you think.
Nobody Ever Said Safety Would Be Easy
By Phil La Duke
Occam’s Razor is one of those things that a lot of people cite, more have heard of it, and in safety, many more use it to jump to conclusions. Perhaps the most often cited simplification of Occam’s Razor is “when looking for an explanation as to why something happened, the simplest explanation is usually the correct explanation.” Before the army of pedantic boobs mobilize and reign down a flurry of insults at my oversimplification of Occam’s work (which, for the record, experts don’t believe he actually invented) I should say that I fully and whole-heartedly admit that a) this is indeed an oversimplification but it’s not my oversimplification, and b) this oversimplification really belies a misunderstanding of what Occam’s Razor really says. La Duke’s Razor would be “The easy solution to worker injuries is generally the most popular, irrespective of its effectiveness.”
That having been said, too often, incident investigations assume that the simplest cause is the correct root cause and that conclusion, while comforting, is irresponsible ─ even dangerous. Take the all too common root cause of “operator error”. The conclusion that a worker was harmed because he or she erred is satisfying; if an investigator asks “why?” the answer is the variation on Murphy’s Law that says, “shit happens”, or for those of you scandalized by my scatological idiom, “nobody’s perfect”. The contention that everyone makes mistakes is a facile but deeply satisfying conclusion. When investigators conclude that a plane went down killing all aboard because of “pilot” error, we sigh a collective “thank God it wasn’t terrorists” sigh of relief, slap each other on the back and it’s “Miller Time”. Occam’s Razor and Murphy’s Law support the errant worker as proximate injury cause and who are we to argue with a dead guy and a fictitious guy? Certainly a fair number of injuries result immediately or soon after a worker errs, but until we understand exactly why a worker erred we will never have a complete understanding of the circumstances that led up to the injury and without that understanding avoiding future injuries caused by these unknown elements are complete luck. (I am fond of pointing out that in general lucky people win lotteries; I’m not sure I would categorize someone who narrowly escapes serious injury as lucky; they just aren’t fatally unlucky.)
Some injuries are tough for us to see beyond the obvious and the easy. Take for example the time I was walking on a sidewalk abreast of a colleague and a customer. As the three of us walked side by side we approached a temporary sandwich board and instinctively moved to the left to avoid the sign. As we did so, I stepped partially off the sidewalk and fell striking my knee against the sidewalk. My pants were torn and I skinned my knee. The most severe injury was too my dignity. If we use the standard 5 Whys it goes something like this:
Problem Statement: Worker tripped because he stepped off a sidewalk which caused him to lose his balance and fall and strike his knee against the side of the pavement.
Why? Worker moved to avoid a temporary sign but failed to verify that the area to which he was moving provided sufficient space to safely walk on the surface.
Why? Worker was distracted by a conversation he was having with his companions and committed an error.
Why? The worker was distracted because he was discussing a safety issue with his colleague and customer.
Why? The group was on its way to a lunch meeting.
Why? Because there was no other time to have the meeting and also have lunch.
Such facile, linear logic sure feels good, particularly because (whether we admit it or not) it leaves the injured party holding the bag, sprinkle in some creative case management and garnish liberally with administrative pressures to achieve zero injuries and you can substantially improve your safety performance without reducing your risk one wit.
Truth be told, the simplest explanation doesn’t scratch the surface of the factors in play in this example. Off the top of my head here are some of the key contributors to the incident:
- A sandwich board sign was placed on a crowded sidewalk that impeded pedestrian traffic.
- The height between the sidewalk and the parking lot was slightly higher than usual.
- The sidewalk was uneven
- There was heavy pedestrian traffic
- The sidewalk was adjacent to parking (the front of the come cars were parked against the sidewalk and in some cases cars were hanging over the sidewalk.)
The simplest explanation is that I wasn’t watching where I was walking and I fell. In other words: I screwed up and I got hurt, and to some extent I would have to agree. My first instinct is to admit that I needed to be more careful and watch what I am doing. But as pat an answer as that is, it doesn’t begin to tell the whole story. I WAS watching where I was walking, however, the sudden shift of the pedestrian traffic forced me to decide to move off the sidewalk (which would have meant walking into parked cars), collide with my colleagues (which would have forced them back into the sandwich board) stop until the path was clear (which would have risked having the people behind me collide with me), or step on the edge of the sidewalk and take care to maintain my balance). People take risks like this every day, heck I’m sure I’ve taken risks like that many times in the past and not been harmed. My assessment of the risks associated with my actions are that I probably won’t get hurt and if I do get hurt it probably won’t be serious; it’s easy to waive off any precautions as overly cautious.
It’s tempting to see simplest possible cause as the proximate cause because if we do it absolves us of having to do anything meaningful in the way of prevention. If the proximate cause of the injury is my carelessness the organization need only tell me to be more careful. If complacency is to blame for an injury the organization only has to tell people to stop being complacent. But if the problem is complex the prevention is likely to be difficult if not impossible. Let’s look at the example of my fall. What could we do to prevent this convergence of hazards? A quick look at the hierarchy of controls is pretty disheartening. Realistically eliminating the hazards (heavy pedestrian traffic, cars parked adjacent to the sidewalk, a sandwich board blocking the flow) while possible isn’t feasible. We all know how hard it is to engineer out hazards once the bricks have been laid and mortar poured. Substitution is equally unfeasible, realistically the only thing we can substitute would be the sandwich board which the shopkeeper would likely resist any substitution, having selecting the sandwich board for its effectiveness and relatively low-cost. That leaves us with administrative controls ─ the police could ticket drivers for parking too close and blocking the sidewalk, outlaw sidewalk sandwich boards, or even establish rules requiring pedestrians to walk single file down the side-walk ─ and I think we can all imagine how effective these would be. I suppose we could require everyone to wear knee pads but count me out.
So we are left with two choices here equally loathsome: either we can take the easy route and decide that my injury was the result of my own carelessness and remind me to be more careful, or we can decide that the injury was the result of many interrelated factors that combined to raise the risk of injury to a level where someone was bound to be injured, and make corrective action difficult if not impossible.
It amounts to this, philosophically I believe as many do, that all injuries are preventable, but I also believe that sometimes preventing some specific injuries just isn’t feasible so individuals and companies decide it’s just better to live with the risk.