There is a story, so beloved of professional problem solvers that it has become a virtual “article of faith” in the problem solving community. A tale so compelling, that although the story predates Google by almost a decade, and despite never warranting an official publication, there are reportedly more than 100,000 pages online which reference the study in some way.
The story, which addresses the woes of the Jefferson Memorial in Washington DC, is used as a method to extol the virtues of the 5-Whys method of structured problem solving. To recap, 5-Whys is a simple, stripped-down method of root cause analysis (RCA) in which the investigator repeatedly asks, “why?” in order to drill down from higher-level symptoms to the underlying root cause of a problem. The parents amongst you will have encountered this from your kids (they stop doing at around age 25 I’ve been reliably informed).
Our story begins back in the late 1980s, when US National Parks managers noticed that the Jefferson Memorial was crumbling at such an alarming rate that it would quickly become dangerous to visitors. When they asked why (1) this could be, they were informed that it was being washed with strong chemicals far more frequently than any of the other DC memorials. For most teams, the investigation would stop here. The solution has been found, of course. Reduce the cleaning frequency to match those of the other memorials.
Unfortunately, that solution wasn’t acceptable. It would have resulted in a filthy, unhygienic Jefferson Memorial. This clearly wouldn’t cut it in Washington DC, a city of such national and international significance. By employing classic 5-Whys thinking the team could surely find out what else could be done?
Next up the investigation team enquired as to why (2) the memorial was being cleaned so frequently? They discovered it had an exceptionally large amount of bird droppings deposited on it every day. What’s the solution now? Use scarecrows? Fly hawks? Bring in Elmer Fudd or the Duck Dynasty crew and declare open season on pigeons?
Luckily (for the pigeons, anyway), the Parks managers kept inquiring. When they asked why (3) the birds seemed to prefer the Jefferson as a toilet, compared to monuments like Kennedy or Lincoln, they discovered that the Jefferson harboured an incredibly large population of spiders and similar insects upon which the birds were eagerly feasting. Why (4) on earth was this? An eminent entomologist from Baltimore, Prof. Don Messersmith was contacted, and he discovered that the population of spiders had exploded because of an abundance of midges and similar insects that had made the area around the monument their home.
When the Parks managers asked Prof. Messersmith why (5) so many midges congregated on the Jefferson memorial, Messersmith told them what any fresh water fisherman already knows – Midges are triggered to emerge and mate by a particular level of light. And it just so happens that the Park managers had been inadvertently creating this unique quality of brightness by turning the memorial lights on just before dusk.
So, according to our tale, this one variable (light levels) caused this pattern of cause and effect; lots of midges, lots of spiders, lots of pigeons, lots of droppings, lots of chemicals during lots of washing – all leading to the inevitable deterioration of the statue.
Expressed as classic 5-Whys we can illustrate this in the following way:
Problem: One of the monuments in Washington D.C. is deteriorating.
Why #1 – Why is the monument deteriorating?
- Because powerful chemicals are frequently used to clean the monument.
Why #2 – Why are powerful chemicals needed?
- To clean off the excessive volume of bird droppings on the monument.
Why #3 – Why is there an excessive volume 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 flying 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 at the monument in the evening attracts the local insects.
Solution: Change how the Jefferson is illuminated at dusk to prevent the arrival of swarming insects.
The tale tells us that, by using 5-Whys, the solution ended up being incredibly simple and actually saved the Parks Department a great deal of money on chemicals, labour and administration, namely to just wait until dark to turn on the lights.
What more could we ask for?…
The Alternative Take.
Except, what if it was never as simple as this? What if, after 30 years of teaching this example, emboldening thousands upon thousands of 5-Whys problem solving disciples, leading to tens of thousands of articles, we discover that the 5-Whys method didn’t actually uncover the layers of this problem and that the solutions chosen were not quite as simple, nor as effective as we have been led to believe all these years?
Let us investigate further via a series of challenges assembled from information that is readily available in the public domain (after all, there are 100,000 articles to purvey!).
Debunk 1. Although the tale speaks of the unique nature of the Jefferson Memorial official reports, published in 1989, state that several memorials across in DC were a similar condition, regardless of their unique environmental conditions.
Debunk 2. The investigations undertaken throughout 1989 and 1990 were not undertaken by plucky amateurs as implied by most iterations of the tale. In fact, they were part of an in-depth multi-disciplinary investigation performed by a team of highly trained problem solvers hired by the National Park Service (to the tune of $2 million, as you ask) to perform a year-long study of the widely acknowledged deterioration of DC memorials.
Debunk 3a. Most versions of the story cite the harsh chemicals required to remove bird droppings as the ‘root cause’ of the problems effecting the monument’s stonework. Documents produced back in 1989/1990 state clearly that although chemicals did contribute they only contributed in combination with other factors. Most significantly the ‘excessive’ quantity of water used throughout the cleaning process, and the pressure at which it was applied.
Debunk 3b. Furthermore, acid rain, air pollution and littering tourists were also cited as contributing factors of note. News articles published at the time stated that the Parks Service must “dramatically reduce the volume of water used to wash the monuments”, even going so far 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.
Debunk 4. Reports also stated that the majority of the discolouration was not caused by bird droppings. It was, in fact, the midges and bugs themselves that discoloured the stonework. It is true, nevertheless, that the lighting used, did attract a substantial percentage of the insects to the buildings.
Debunk 5a. The impact of the Jefferson Memorial story is delivered by the fact that the chosen solution (to delay lighting till full darkness, and reduce overall brightness) was more effective, quicker and far lower in cost than any other consideration. In the first instance, this solution was extremely effective, reducing bug communities by 85% within just a few weeks. However, the replacement lighting systems across the city took a full 5 years to implement and eventually cost upwards of $25 million in public money.
Debunk 5b. Although the solution was extremely effective (and ultimately saved on energy costs too) it was never implemented beyond an initial 6-week trial period! After several years of lobbying from various public bodies and complaints from residents, businesses, tourists and photographers, fearful of being robbed of their stunning images of great monuments glowing next to the mighty Potomac River, the government finally abandoned their decision to permanently restrict lighting levels in the early evenings. A timely reminder that in the real world some solutions can be extremely effective as well as offer an undeniable return on investment but, due to strategic, environmental or cultural (and unforeseen) obstacles they can never be implemented.
Debunk 6. In place of the highly effective, but short-lived decision to change the lighting policy there are now a host of solutions in place to dissuade birds, spiders and midges from congregating on the memorials. These reportedly include the installation of wires, metal spikes, netting, scarers and clear plastic. The cleaning processes have also changed; the quantity of water has been reduced and the way in which it is applied has changed. And, crucially, the chemicals that are used are now far less aggressive. Fundamentally though, the demands of the viewing public have changed, leading to a more realistic and pragmatic expectation of the appearance of the monuments.
What have we learnt here?
Firstly, Satirist HL Mencken, from nearby Baltimore, couldn’t have been more apropos when he wrote half a century earlier that ‘For every complex problem there is an answer that is clear, simple, and…wrong’. The answers delivered in this story were clear, they were simple, and they were, alas, also wrong.
But like all good debunked stories, there is still much to be learnt from the apocryphal tale of the Jefferson memorial. Just maybe not exactly what we thought. Perhaps what we really gain here is a more realistic picture of the huge difficulty of solving complex problems under real world conditions. And that only via a genuine understanding of cause and effect do we discover the wider spread of solutions that we almost always need to apply in the real world. But crucially, we are reminded that when a lesson is this plausible, almost all of us are blind as to its questionable validity.
So, let us keep sharing the Jefferson Memorial story, but no longer as an encouragement to adopt 5-Whys, but rather as a warning not to be seduced by its compelling simplicity.