Keep it simple! A meeting with Enrico Fermi
Are you able to Keep it Simple? That’s the secret to efficiency, effectiveness and success
I clearly remember the day I learned about it.
It was in the summer of 2010. In Limpopo Province, South Africa, I was near Kruger National Park, very close to Africa’s amazing wildlife. We were in the middle of a workshop, presenting a Decision Support System (DSS) to local municipalities.
The DSS was an innovative community-based tool to support identifying and implementing eco-sustainable income generation activities. The model grew in complexity during those trial sessions, with too many variables and assumptions.
Enrico Fermi’s Method: Keep It Simple
On that day, our scientific advisor – Dr David Cummings – invited the participants to keep the number of parameters under control. He quoted Italian physicist Enrico Fermi:
“How many arbitrary parameters did you use for your calculations? […] I remember my friend Johnny von Neumann used to say, with four parameters I can fit an elephant. With five I can make him wiggle his trunk” (1954).
Professor Enrico Fermi was known for “managing to find the simplest and most direct approach, with minimum complication and sophistication.
He disliked complicated theories, and while he had great mathematical ability, he would never use it when the job could be done much more simply.
He was famous for getting quick and accurate answers to problems that would stump other people. Later, his method of getting approximate and quick answers through back-of-the-envelope calculations became known as the “Fermi method“.
The K.I.S.S. principle
That day, Dr David Cummings went further with his lecture, quoting the KISS principle (keep it simple…stupid).
Far from any pop-culture influence, the K.I.S.S. principle was actually coined for US aircraft design; it states that:
The principle is best exemplified by the story of Johnson handing a team of design engineers a handful of tools. The challenge is that the jet aircraft they were designing must be repairable by an average mechanic in the field under combat conditions with only these tools. Hence, the “stupid” refers to the relationship between how things break and the sophistication available to repair them.
Other optimisation principles close to the Keep It Simple principle
Needless to say, it was a memorable lecture and a new opportunity to re-discover Enrico Fermi as well as other similar methods (Occam’s razor, Poka-yoke (ポカヨケ). Indeed, I like to refer to Fermi’s method and similar schools of thought whenever I use analytical models (financial, business, decision, etc.). It is not only a problem of scientific rigour: over complexity causes confusion, delays, and procrastination. It is the enemy of execution.
I still have the scientific article given to me after the workshop (A Meeting with Enrico Fermi, by Freeman Dyson). You can download it from this here.