Assumptions, assumptions

What you think you know will hurt you. Everybody knows it.
Personal failure affects you and perhaps those depending on you. The higher up on the power scale you rank, the higher the number of those affected.

Assumption-based mistake types

Battle of the Somme, northern France. After pounding German defences for about one week, the British think the dead-quiet around the battlefield meant that the German deeply-entrenched defenders had been annihilated.
July 1st, 1916, was the darkest day in British military history: a complete failure military-wise and the heaviest single-day human toll ever sustained by British forces (a total loss of 57,470, of which 19,240 dead).

ABMT #1: "the danger isn't there because I can't see it"

Cape Canaveral, FL, 28th January 1986: Morton Thiokol's engineers tell their management the Challenger shouldn't fly because there's a "100-year cold" going on.
Management relays to NASA, of which the top brass, under pressure from DC, go, "reconsider the recommendation". Management at MT relay back to their engineers something like "prove that it cannot fly".

ABMT #2: "I am right because you cannot prove me wrong"

Pearl Harbour, HI, 7th December 1941: Suffice it to say that part of the japanese force was even detected by an american radar outpost - and dismissed as probably a training flight.

ABMT #3: "I can't see how they could make it, so they can't"

The list of ABMTs goes on and on.
The heavier the toll, the harder the lesson: "Never make assumptions", my trainer Nikki Riddle used to caution me and my fellow trainees. Easier said than done.

What is your Pearl Harbour ?

Rui Costa
Tue, 27th Feb, 2007
Lisbon, Portugal