The Wrong Place At The Right Place: A Study In Variability

variability

by Phil La Duke

Recently I was talking to a friend who had been injured on the job, not seriously thank God, but enough for it to be a recordable.  I asked her how it happened, fully expecting her to give me the same old “I was stupid, I …” excuse that we tend to get when people feel that whatever they were doing right before the accident was ultimately the result of their own stupidity, carelessness, or mistakes.  Her answer surprised me—although it shouldn’t have. She said, “I honestly don’t know…I mean I did the same thing I always do, only this time I got hurt.” I questioned her further, reasoning that (as I always argue) if one does the same thing every time one will either never get hurt or always get hurt, that’s  the only two outcomes. While this makes for good hazard recognition training (it refutes the whole “I didn’t do anything wrong I swear” argument) it is yet another instance where I am chiefly full of crap.

I don’t expect many of you to argue (I get virtual reams of eHatemail telling me such) and I am neither fishing for compliments nor feeling sorry for myself.  The simple fact is that my friend could be absolutely correct: she may have done things exactly the same and still got hurt.

It’s worth saying that she probably wasn’t doing things exactly as she “always does”.  This doesn’t make her a liar, but it does demonstrate the mistaken believe under which most of us labor, that is, that we do things the same way every time.

Let me illustrate, I walk my two rowdy black labrador mixes 2 miles every morning; I do the exact same thing—we walk the same route, stop at our neighborhood party store where I buy 4 Diet Dr Peppers and head home.  We do the same thing every day…except when we don’t.  You see, while it’s easy for me to SAY (and believe) that I do the same thing every day I really don’t and here’s where it get’s messy. First we have to define “the same”. To be sure I have a process, I get up, put the harnesses on the hound, grab a couple of plastic bags or disposing of waste and we head out westbound on our route.  But how much is this really the same from day to day? My alarm goes off at 6:52 every morning, of course there is variability in the cheap alarm clock that I use but so little that it’s not worth mentioning, but it still is VARIABLE.  Sometimes I get up full of energy and am ready to go, other times I may hit the snooze and get up 10-20 minutes later. I get dressed, use the bathroom, and head down stairs. About half the time I forget my phone on the charger in my room and head back to retrieve it Sometimes the younger of the two dogs decides to wriggle and growl and squirm which she thinks is great fun. Sometimes the older of the two balks at the sit command usually we take our respective pills before we walk but sometimes I forget and we take them when I get home. These variables (and many more) effect exactly what time I leave the house, and each one of these variables exist in a universe filled (with what are, for all intents and purposes) are infinite variables. (I know that there are theoretical limits, but for practicality’s sake there isn’t much difference between the infinite and the finite in this case.) I have been doing this routine most every day for the last 13 years and I am essentially doing the same thing every day.  If my assertion that “if you do everything the same way you either always get hurt or you will never get hurt” is correct than I should never be injured on my dog walk.

Mostly the Same Isn’t Exactly the Same

I have been injured three times on my dog walk, fortunately never seriously, but I have seen my fair share of near misses.  There are several areas of my walk where there are uneven rises in the concrete sidewalks, on at least four occasions I nearly tripped on these hazards. Given that I have interacted with these hazards approximately 28,840 times (approximately 700 walks a year (two a day less a conservative estimate of how many I may have missed because I was traveling, sick, or unmotivated) times 13 times the number of hazards) the fact that I have only had four near misses is remarkable. So, since we’ve established that I do things “mostly the same” and not “exactly the same” we can readily explain why, despite so much interaction, there have been so few incidents, because the many factors that must be present for me to stumble, fall, and injure myself .  In fact, the near misses have been so far apart that  I am surprised each time I stumble.  If this were a workplace incident what would be Safety’s response?  We may well cordoned off the area until maintenance can correct the hazard. Keep in mind, I am not the only pedestrian who walks this portion of the route so while my experience is real and valid it is only one data point and we can not assume that my experience is universal. Additionally, while my risk is seemingly low, what about children who bicycle on the sidewalk? (in my municipality, it is illegal for people over the age of 13 to ride a bicycle on the sidewalk, a law that is almost universally ignored) or people who run on the sidewalk? The risk differs in each case because of the variability in our behavior and interaction.

Are We Miscalculating Risk?

The risk of me falling on these hazards are presumably pretty high, but they aren’t really.  We tend to calculate risk as Duration x Probability x Severity and when we do so we tend to treat all three of these factors as carrying equal importance.  Anyone who has risked being injured because he or she was only going to be interacting with a hazard “for just a minute” can tell you that the duration of exposure is not necessarily equal to the severity of injury. We we in a laboratory we might be able to come up with reliable statistical models for the average duration, average probability (which is subdivided into probability of interaction and the probability that such interaction will result in an incident) and the most probable severity (almost any hazard has the theoretical possibility of causing a fatality, just as almost any hazard has the theoretical possibility that a person can interact with the hazard and escaped unharmed), but think of how “dumbed down” this risk truly is.  For it to be meaningful it needs to be a calculation not just of MY risk of injury but EVERYONE’s risk of injury, so we talk about averages: “what is the average duration of exposure?” “what’s the AVERAGE probability?” “What’s the most likely severity?” Can we ever get a statistically valid (assuming that we are dealing with a normal distribution) predictor of risk of injury, and what’s more, is it really that important that we do?

Balancing Risk

Risk is not constant, it’s contextual.  While we might talk about conditions as “safe” or “unsafe” we are really deluding ourselves.  There is no such thing as an absolutely, 100 percent “safe” condition because everything carries with it some risk and if there is a trillionth of a chance that something can harm you, well then there’s a chance that it can harm you and the best we can say is that something is “safe enough” or “safer” than an alternative. The minute we start preaching safety (and that ship sailed a LONG, LONG time ago) we start advocating for the impossible.  If we ask our people to make binary decisions—that is, a choice is either “safe” or “unsafe” we effectively force people to get comfortable making unsafe choices because, let’s face it, something done as frequently as driving is unsafe and, because there are no desirable alternatives we do it any way.  Is the workplace so different from our day-to-day lives?

Safer Choices Not Safe Choices

The key to a safer workplaces lies not in getting people to make safe choices (nothing would ever get done) rather in getting people to make safer choices. Instead of having people ask themselves if what they are going to do is safe, we should be encouraging people to ask themselves how they can make what they are going to do safer.  Through relentless pursuit, not of the safest POSSIBLE solution but, of a safer solution we stand the best chance of making advances in workplace safety.

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