When you think of the great individuals in lean history, what names come to mind? W. Edwards Deming. Taiichi Ohno. Shigeo Shingo. Don Messersmith. Oh, you’ve never heard of Don Messersmith? Perhaps, you’re not familiar with the name, but I can almost guarantee that you are familiar with his work.
Don Messermith is an esteemed professor emeritus at the University of Maryland. His accomplishments in the field of entomology – the scientific study of insects – are many, as evidenced by the extensive list of distinguished titles, prestigious awards, and publications that bear his name. But among his comprehensive catalog of contributions, one study in particular stands out above the rest.
Although the work predated the Google search by nearly a decade, and despite never warranting an official publication, there are more than 140,000 pages on the internet which reference the study. As a matter of fact, it’s quite likely that there is only one surviving copy of the work still in existence today. So, why should we care about some little-known, unpublished report from a study on insect behavior performed almost 25 years ago? Because sitting in a file folder in the desk drawer of Don Messersmith resides a report on perhaps the single, most famous problem ever solved:
Messersmith, Donald H. 1993. Lincoln Memorial Lighting and Midge Study. Unpublished report prepared for the National Park Service. CX-2000-1-0014. N.p
If you’ve ever taken a course on the topic of scientific problem solving, it’s highly likely that you’ve heard this tale of crumbling monuments, foul birds, swarming insects and simple solutions. Although the subjects of the study were decidedly of the two-, six-and eight-legged variety, the work has become the quintessential case study on the application of the “5-whys”.
The Classic 5 Whys Example: A Monumental Mystery
The 5-whys is a method of root cause analysis in which the the learner repeatedly asks, “why?” in order to drill down from higher-level symptoms to the underlying root cause(s) of a problem. So critical is this line of logic to lean thinking that Taiichi Ohno once described the method as “the basis of Toyota’s scientific approach . . . by repeating why five times, the nature of the problem as well as its solution becomes clear.”
As any parent can attest, children are remarkably astute in their ability to repeatedly ask why when they wish to learn about their world. The grand lesson of life is the discovery that all things in the universe are what they are “because mommy said so!” It is likely this realization that ends our fascination with the word “why” at an early age. This is why, as an instructor teaching the technique to adults, it helps to have a strong example to restore the credibility of repeatedly asking why in the context of problem solving.
Enter the work of Don Messersmith, whose study on the lighting of the memorials in Washington D. C. has become cannon to the teaching of the 5-whys method. Due in part to the scarcity of the source document, many different versions of the tale exist today. And while you may have learned a slightly different version, the general details of the story are as follows:
Problem: One of the monuments in Washington D.C. is deteriorating.
Why #1 – Why is the monument deteriorating?
- Because harsh chemicals are frequently used to clean the monument.
Why #2 – Why are harsh chemicals needed?
- To clean off the large number of bird droppings on the monument.
Why #3 – Why are there a large number of bird droppings on the monument?
- Because the large population of spiders in and around the monument are a food source to the local birds
Why #4 – Why is there a large population of spiders in and around the monument?
- Because vast swarms of insects, on which the spiders feed, are drawn to the monument at dusk.
Why #5 – Why are swarms of insects drawn to the monument at dusk?
- Because the lighting of the monument in the evening attracts the local insects.
Solution: Change how the monument is illuminated in the evening to prevent attraction of swarming insects.
I use this 5 whys example frequently in my own classes, and, because of its effectiveness and its ability to engage, it has become my absolute favorite slide to deliver. The story drives home a powerful point: deep understanding of the root causes of our problems yields simpler, more effective, and less costly solutions. In fact, the lesson is so effective, that many learners are cynical as to its validity. After years of questions from students, I set out to research the topic and to separate fact from fiction in the tale of the eroding monuments. In doing so, I had the great honor of corresponding directly with Dr. Messersmith to review the details of his work first-hand.
What should not be surprising is that the story is not entirely true-to-life, but neither should it be considered a work of fiction. Some trivial points have simply been confused over time, but some not-so-trivial details have unfortunately been omitted from the retelling of the tale so as to create a simpler, more plausible study. In this case, truth is indeed better than fiction, and when added back into the fold, the missing pieces of the story actually paint a much more robust and complete picture of the nature and complexity of real-world problem solving.
Debunking the 5-Whys Example Folklore
The following discussion of the myths associated with the 5 whys example are based on available source documents (links provided where possible) and on direct correspondence with Dr. Messersmith himself.
Myth #1 – Whose Monument is it, Anyway?
The first bit of mystery surrounding the tale is the exact monument that was experiencing the deterioration. Some versions specify the Washington Monument, some the Lincoln Memorial and others the Jefferson Memorial. The facts are that the case study is relevant to both the Jefferson and the Lincoln memorials, but not specifically the Washington Monument. As detailed in this article from the Associated Press in 1989, a group of private consultants were hired by the National Park Service (to the tune of $2 million) to perform a year-long study of the deterioration of the Lincoln Memorial and the Jefferson Memorial.
In April of 1990, the consultants published a report which found that “the increasingly toxic effects of nature” had accelerated the erosion of the monuments and that immediate steps were required to address “very serious structural problems”. A Park Service representative responded to the findings by assuring that “both memorials are in excellent shape overall” and that there was “absolutely no danger to the public”. Less than one month later in May of 1990, a 50 lb. block of marble fell from the volute on the top of a column in the Jefferson memorial. Thankfully, no one was injured, and major repair and rehabilitation projects were subsequently initiated to address the deficiencies in both monuments.
Myth #2 – Cleaning Chemicals as the Culprit
In most versions of the story, the erosion and degradation of the monuments were attributed to the use of the harsh chemicals needed to remove the bird droppings from the monument’s surfaces. This explanation falls short of the complete truth in two ways.
First, the act of cleaning was cited only as one contributing factor among many – like acid rain, water seepage, air pollution and littering tourists – to the damage observed on the memorials.
Second, cleaning chemicals were not causing the lion’s share of the deterioration. Rather, per the consultant’s report, it was actually the large volume of water applied during the cleaning process that was found to pose the greatest threat to the marble and limestone buildings. As later detailed in this government investigation into the falling chunk of the Jefferson Memorial, when water seeps into inclusions in marble and limestone, it drives further propagation of the cracks, which may result in structural deficiencies.
Although very little could be done to reduce the volume of exterior rainwater to which the memorials were exposed, measures focused on reducing the volume of water used internally within the monuments as part of the cleaning process. The Associated Press article from 1990 stated that the Park Service had “dramatically reduced the volume of water used to wash the monuments”, even going so far to to say that they would need to “educate the public to understand that these buildings may not appear as pristine white in the future as they once did” because of the reduction in water used to clean them.
Myth #3 – Cleaning was for the Birds
It is true, the large prevalence of bird droppings – specifically from starlings and sparrows (not pigeons) – did contribute to the need for a daily scrubbing of both monuments. However, the bulk of the mess was not cause by a bird byproduct. As the story goes, midges (not gnats) swarmed to the river-side monuments because the lights replicated their preferred, dusky mating conditions.
Rather than doing the deed over the water, the lights drew them inland in vast swarms where they splattered against the monument walls to deposit their eggs in the form of dark – not to mention hard-to-clean – masses. Although the prevalence insects did invite a large population of spiders, which in turn brought the starlings and sparrows, it was the midges themselves that necessitated the bulk of the bathing.
Myth #4 – Shedding Some Light on the Solution
When it came to the lighting of the monument as a solution to the problem of deterioration, there are really two separate myths at play.
First, the true impact of the story comes from the belief a simple, low-cost solutions can effectively prevent recurrence of major problems, when more-complicated and more costly alternatives would likely fail to do so. For this particular problem, however, this is not the case. It must be noted that the suggested lighting change was just one of many actions taken in response to the larger problem. In fact, the list of improvements took more than five years and $25 million to complete, and included a detailed analytical characterization of every single piece of stone in both monuments.
Second, (and this is where the whole story becomes very interesting), delaying the lighting at night was indeed successful in reducing the number of midges AND there was the added bonus of money saved on energy costs, BUT YET the improvement still was not implemented long-term. Yes, you read that correctly. Allow me to elaborate.
In early 1990, Park Service officials agreed to a six-week pilot program during which the lights around the memorials were turned on one hour after sunset on Mondays, Wednesdays and Fridays. Don Messersmith and a team of students proceeded to count the number of midges on the monuments on these nights and compare them to the nights in which the lights were turned on before sun down. After 6 weeks, and as predicted by Dr. Messersmith, the change in the timing of the lights resulted in an 85% reduction in midge infestation. Everyone initially seemed pleased with the results of the pilot study. . . well, almost everyone.
The Jefferson and the Lincoln Memorials sit along the banks of the Potomac River, which creates quite a picturesque setting for photographers to apply their craft. The change in the timing of the lights drew ire from those seeking to capture breathtaking images of an illuminated memorial against the backdrop of a sunset blazing across the river. As of this January 1992 article, Park Service officials were still evaluating whether to pursue a permanent change to the timing of the lights, but by September of 1995, the countermeasure was no longer under consideration due to the overwhelming number of complaints from photo-seeking tourists.
The article continues to detail the actions that were taken over the subsequent FIVE YEARS(!!!) to dissuade birds, spiders and midges from congregating on the memorials, which included the installation of wires, metal spikes, netting and clear plastic. But without addressing the underlying root cause of the problem (the timing of the lights), these actions had little to no impact on easing the amount of cleaning required.
Unfortunately, at this point, in September of 1995, the trail of new information goes cold . . .
The Moral of the Story
Like all good stories, there is much to be learned from the tale of the Lincoln and Jefferson memorials. But without knowing the whole story, it’s difficult to say exactly what the most important lesson is. Maybe it’s the value that a thorough understanding of cause and effect has on the efficiency and effectiveness of solutions. Maybe it’s the difficulty of solving complex problems under real world conditions. Perhaps, however, it’s the importance of hope. Yes . . . hope. Because if these recent images of the Lincoln Memorial and the Jefferson Memorial at sunset are any indication, than there might just be hope for my government yet.
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The KaiZone would like to formally thank Dr. Don Messersmith for taking the time out of his busy schedule to contribute to this piece. This piece would not have been possible without his input.
Awesome detective work. Teaching the 5 Why’s will never be the same for me anymore.
I actually stopped using this 5 Why example a few years ago because I thought it trivialized a difficult concept. Getting to root cause is not as simple as asking a question and getting an answer. In real world problem solving answering a single why with a definitive answer is difficult. My experience is that when someone shows me five why’s with five answers, the answers can not be backed with real evidence. I will take two why’s with reproducible evidence over five why’s and unbacked assumptions every day. In practice a coach or mentor using the five why methodology needs to follow each why up with a series of other questions to get a deeper understanding of the thinking that lead to the answer.
The real story as you have told it here is a much more useful case study. Even the fact that they were never able to implement the countermeasure because it had unintended consequences rings true to me. Countermeasures need to be tested in a PDCA methodology. I could see recreating a training session around this where you show the simple dumbed down version that is so popular and then talk through the realities of problem solving and all of its difficulties with what actually took place.
Thanks for this.
Kris – Great perspective! I am aligned with you on just about every point you make above, and actually have a follow-up article planned in the coming months on this exact topic.
You are dead-on that the “dumbed down” version of the story trivializes the thinking behind root cause analysis. From my experience, would-be problem solvers who have only been exposed to the tool in “training” start with a belief that root cause analysis is simple (just ask “why”, right? How hard could that be?). The tool itself may be simple, but the thinking that the tool requires to yield meaningful outcomes EXTREMELY complex. Not only is answering a single “why” difficult as you point out, but framing the “why” questions effectively also requires a great deal of thought and effort.
After learning the true story, I’ve completely changed the way that I teach the tool. I give the dumbed down version first, and then hit the class with the real story. It has become a much better example for my students and produces some real thought-provoking dialogue. I would encourage others to do the same. If you try out that approach, please do come back and let me know how it goes.
Thanks for the great comment!
I use that example in class as well, and someone just asked if it was true, but I didn’t know how to answer. Good timing!
Also, I’m looking for another example I use in class. This is where a Toyota part was built with less variation than another automaker’s part, and the Toyota part had greater reliability, even though both met the specifications. Does anyone know the origin of that study?
Etymology is the study of a word’s derivation, please. Entomology is the scientific study of insects. This mistake took away from the legitimacy of the article for me personally.
Thank you for highlighting the typo. The mistake has been fixed, and I can assure you that I have severely reprimanded the autocorrect function on my computer for this obviously careless error.
The grammar nerd within me is grateful and thanks you for the insightful article!
Thanks for pursuing this mystery! Was Dr. Messersmith aware of the popular mythology that had grown out of his research? Given that the real story is so much more complex (at least compared to the neat and tidy urban legend), I’m curious if he had any thoughts on how or why the story had morphed like it did…
Jason – Thanks for reaching out. Indeed, he was aware that his work had gained recognition beyond well-beyond the original intent, but that no one had previously attempted to contact him to set the story straight. In my exchanges with him, he never elaborated about his personal feelings on the matter (despite my best efforts to get him to do so). He chose instead to limit his commentary to the facts vs. the myths of the case. Unfortunately, he was in the midst of dealing with some very significant personal matters at the time that I first reached out to him, so I chose not to take up too much of his time / energy to probe the situation further. Hope that helps!
Hi Joel, I love that you explored the accuracy of this story! Having shifted from the academic world (where all statements must be accurate and adequately referenced) to the corporate world (where many “consultants” appropriate academic work with poetic liberties and a lack of reference), I have been baffled by how little research is done regarding the examples people use. I like to call these stories “Business Legends”: Urban legends that work at work!
It really is true, the top prevalence associated with bird poop – particularly from starlings and sparrows (not pigeons) – do contribute to the advantages of a daily scrubbing up of each monuments. But the bulk of the actual mess had not been cause with a bird byproduct.
Thanks for solving my curiosity. I’ve been using this story not only to emphasize the importance of finding root causes to solve a problem but also to show how a problem can be solved by finding and resolving a contradiction(a concept in TRIZ) hidden in it. After analyzing the contradiction “the light should exist and should not exist” we can find many solving directions which can improve the situation by asking exactly when, where and to whom the light should exist or should not exist.