KISS
A design principle that most systems work best when kept simple rather than made complex. Simplicity should be a key goal, and unnecessary complexity should be avoided.
Origin
The acronym — "Keep It Simple, Stupid" — is credited to Kelly Johnson, lead engineer at Lockheed's secretive Skunk Works division, where it became a guiding principle around 1960. Johnson's context was military aviation: aircraft aboard the U-2 and SR-71 programs had to be repairable in combat conditions by mechanics with only basic tools, which imposed radical simplicity as a design constraint. The U.S. Navy adopted the principle formally around the same time. The phrase's self-deprecating humor — designating the engineer as the "stupid" one — helped it endure as a touchstone of engineering and design culture for decades.