Michiko Diby wrote a piece on "unknown unknowns" singing Rumsfield's infamous quote about the situation in South West Asia.
Michiko suggests there is nothing we can do as PMs about the unknown unknowns. They just come along and "slap us on the side of the head."
These are actually ignoramus et ignorabimus - we do not know and will not know.
Much like Rumsfield's hubris, we cannot fall into the same trap. The counter to this "we can't possibly know" is David Hilbert's pronouncement:
We must not believe those, who today, with philosophical bearing and deliberative tone, prophesy the fall of culture and accept the ignorabimus. For us there is no ignorabimus, and in my opinion none whatever in natural science. In opposition to the foolish ignorabimus our slogan shall be:
We must know — we will know!
So How Can We Know What We Don't Know?
Ignoring Rumsfield's hubris for the moment, when we're looking for things that can go wrong, there several methodical processes that can be used. Wide Band Delphi is one. Failure Effects Mode Analysis (FEMA) is another. Looking to Lessons Learned from previous engagements is another. Rummy needed only to look at 18th and 19th century history to see where latent "unknown unknowns" could be found.
The same is true with most projects. Some projects are of course "ground breaking." Even the original space programs looked to past performance in the development or aircraft of "unknowns."
So the premise that there are "Unknown Unknowns" is a ease escape if you haven't exhausted all the other paths before reaching the UnkUnk terminal node in the risk breakdown structure.
