The term Unknown Unknowns (UnkUnks) is used in risk management and politics to define an event that no one anticipated. A "low probability event" or a "Long Tail" in probability distribution terms is refered to as a "Black Swan."These are sometimes mixed together, confused between each other, or used in exchange of each other.
The most famous recent quote is Rumsfeld's UnkUnk appearing during the Iraq War.
"There are known knowns; there are things we know that we know. There are known unknowns; that is to say, there are things that we now know we don’t know. But there are also unknown unknowns; there are things we do not know we don’t know." — United States Secretary of Defense Donald Rumsfeld
Nassim Taleb famously uses Unknown Unknowns for his Black Swan analogies. These two authors are sometimes connected in a group of those reminding us that the future cannot be forecast. While Rumsfeld is not in the same class as Taleb when it comes to anti-method language, Taleb does fit into the class of intellectual nihilists . Taleb thinks all quantitative analysis of finance is nonsense. Much in the same way some agilest think software development is not engineering discipline but a "emergent" process pf personal revelations of the needs of the users. This is harsh I realize, but it makes the point that forecasting the future is done every day and deailing with UnkUnks is part of that forecasting.
But let's look at one definition of Unknown Unknowns.
In epistemology and decision theory, the term unknown unknown refers to circumstances or outcomes that were not conceived of by an observer at a given point in time.
There is a critical concept here - conceived of by the observe at a given point in time. This means that in some domains an UnkUnk is a very short sighted and "small world" view of the categories of risk. This categories are well defined by De Meyer, Loch, and Pich's in "Uncertainty and Project Management: Beyond the Critical Path mentality" as:
- Variation - in activity durations, costs and the exact performance level delivered by resources is a common source of project uncertainty.
- Foreseen risks - are identified but uncertain influences in a project
- Unforeseen risk - are not formally identified in the project planning stage, that is, they
are not anticipated, and a “Plan B” has not been formulated. - Chaos - refers to the fundamental uncertainty about the basic structure of the project
plan itself.
The question is Could these supposed UnkUnks have be revealed? How much would it cost in time and money to discover the outcomes at a given point in time?
Or another question might be, are there UnkUnk's that are simply not "knowable." In the physics world (my area of education and first practice) there are many things that are not known, but that does not mean they are un-knowable. There is a difference between Unknown and Unknowable. This is sometimes not well understood in the project management world. There and in the software development domain, not much is unknowable, with the right amount of money and / or time.
Those speaking about UnkUnks often do so in situations guided by the Dunning-Kruger effect
When people are incompetent in the strategies they adopt to achieve success and satisfaction, they suffer a dual burden: Not only do they reach erroneous conclusions and make unfortunate choices, but their incompetence robs them of the ability to realize it.
Rumsfeld's comment is classic. In the Vietnam era, the same approach was taken. Francis Fitzgerald's book Fire on the Lake: The Vietnamese and the Americans in Vietnam. We entered Vietnam with very little understanding of the culture and consequences. There were UnkUnk's but they were of the Dunning-Kruger type.
So Now How Can This Be Applied to the Project Management and Software Systems Domain?
Let's start with another definition from the Business Dictionary:
Future circumstances, events, or outcomes that are impossible to predict, plan for, or even to know where or when to look for them.
While not the OED, it is indicative of the problem in this domain. This definition does not say the unknowns are UNKNOWABLE.
So why would you - as a project manager - embark on a project, that has Unknown Unknowns? Only to then encounter them and claim "well we came across an UnkUnk that killed our project."
Why would you as a manager of a software development project, embark on a mission critical, possibly life threatening (physical or financial) endeavor, and abandon good engineering practices - and worse claim that the development of a product that is somehow "critical" to the success of the firm or mission without a process framework that guides the development of the outcome?
If we move back from the epistemological aspects here and talk about Project Management and product development, the use of UnkUnk's may be seen as a excuse for not "doing your homework." Looks pretty lame to me.
Even more lame when you are spending someone else's money. Or even more than that when you're spending other peoples money for you to have a high probability of success.