In Search of The Best Answer, Not a Better Answer
Whenever there is a major man-made disaster or some kind of accident, responsible officials usually convene a team that conducts an investigation. The results of that investigation will usually identify a “root cause” and several “contributing causes”. If it was a plane crash, the team will probably present the root cause as either pilot error or some kind of maintenance error. But, if you really want to find out what caused the problem and how to fix it, look at the “contributing causes”. Those are the keys to not experiencing that event in the future.
Although, often practiced in a jargon-filled method that does not communicate well to the general public, root cause analysis, provides a tool for us to develop robust, enduring solutions to problems we face, whether they are in safety or in any area we find we cannot accept repeat occurences of that problem. This article will outline what I believe is a better root cause analysis method and how it can be used to develop robust solutions.
“The root cause of the problem in the one you choose to fix… (or blame…)”
The quote above is from a consultant who had participated in several failure investigations, and found that some organizations would argue such that the root cause identified in the final report would either be something they already had a solution for, or could be considered something out of their control. In either case, we can do better.
As an example, let’s consider the problem of a fire that starts in an office building storeroom. We have to identify all possible causes, no matter how remote or whether or not they were involved with the event in question or not, to that fire. In the case of fire, there are always three: fuel, oxidizer, and an ignition source. Next, we identify evidence that those causes existed or not during our event. Those are shown in the next figure.
Now, we could continue and determine causes for our first line of causes. That would be absolutely necessary for several more levels, if we were dealing with a complex problem. However, in this case, my control over the causes can be determined with the information already outlined.
So, what is the root cause of my office fire? The short answer is: That’s the wrong question. All of my causes to the office fire are necessary for that event to occur, so they are all “root causes”. If I eliminate any one of them, it is impossible. And the best part is, if I can eliminate or control more than one, I have a robust solution. A solution that will make the event extremely unlikely in the future. That is our goal.
What remains is the identification of solutions, and then prioritizing based on impact and our ability to implement them. This figure displays some of our possible solutions, with only one eliminated as not being feasible. The greater the number of causes we can eliminate, the more robust is our solution to the problem. If I only choose to remove most of the paper from the storeroom, and one day someone reverses that decision without knowing the reasons behind it, we will again be at risk of the same problem. To create a lasting, successful solution, we must act on preventing as many causes as possible, not just a particular “root cause”.
So, root cause analysis, if practiced correctly, isn’t about assigning blame for a particular event; instead it is about finding true solutions that endure. And, preventing our problems from recurring and history from repeating itself can surely be counted as progress.