KISS, an

acronym An acronym is a word or name formed from the initial components of a longer name or phrase. Acronyms are usually formed from the initial letters of words, as in ''NATO'' (''North Atlantic Treaty Organization''), but sometimes use syllables, as ...

for "Keep it simple, stupid!", is a

design A design is a plan or specification for the construction of an object or system or for the implementation of an activity or process or the result of that plan or specification in the form of a prototype, product, or process. The verb ''to design' ...

principle noted by the

U.S. Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage o ...

in 1960. First seen partly in

American English American English, sometimes called United States English or U.S. English, is the set of varieties of the English language native to the United States. English is the most widely spoken language in the United States and in most circumstances ...

by at least 1938, the KISS principle states that most systems work best if they are kept simple rather than made complicated; therefore,

simplicity Simplicity is the state or quality of being simple. Something easy to understand or explain seems simple, in contrast to something complicated. Alternatively, as Herbert A. Simon suggests, something is simple or complex depending on the way we ...

should be a key goal in

, and unnecessary complexity should be avoided. The phrase has been associated with aircraft engineer Kelly Johnson. The term "KISS principle" was in popular use by 1970. Variations on the phrase (usually as some

euphemism A euphemism () is an innocuous word or expression used in place of one that is deemed offensive or suggests something unpleasant. Some euphemisms are intended to amuse, while others use bland, inoffensive terms for concepts that the user wishes ...

for the more churlish "stupid") include "keep it super simple", "keep it simple, silly", "keep it short and simple", "keep it short and sweet", "keep it simple and straightforward", "keep it small and simple", "keep it simple, soldier", "keep it simple, sailor", "keep it simple, sweetie", or "keep it sweet and simple".

Origin

The acronym was reportedly coined by Kelly Johnson, lead engineer at the Lockheed

Skunk Works Skunk Works is an official pseudonym for Lockheed Martin's Advanced Development Programs (ADP), formerly called Lockheed Advanced Development Projects. It is responsible for a number of aircraft designs, beginning with the P-38 Lightning in ...

(creators of the

Lockheed U-2 The Lockheed U-2, nicknamed "''Dragon Lady''", is an American single- jet engine, high altitude reconnaissance aircraft operated by the United States Air Force (USAF) and previously flown by the Central Intelligence Agency (CIA). It provides d ...

and

SR-71 Blackbird The Lockheed SR-71 "Blackbird" is a long-range, high-altitude, Mach 3+ strategic reconnaissance aircraft developed and manufactured by the American aerospace company Lockheed Corporation. It was operated by the United States Air Force ...

spy planes, among many others). However, the variant "Keep it Short and Simple" is attested from a 1938 issue of the '' Minneapolis Star''. While popular usage has transcribed it for decades as "Keep it simple, stupid", Johnson transcribed it simply as "Keep it simple stupid" (no comma), and this reading is still used by many authors.Ram B. Misra (2004), "Global IT Outsourcing: Metrics for Success of All Parties", ''Journal of Information Technology Cases and Applications'', volume 6 issue 3, page 21
Online version
Retrieved 2009-12-19. The principle is best exemplified by the story of Johnson handing a team of design engineers a handful of tools, with the challenge that the

jet aircraft A jet aircraft (or simply jet) is an aircraft (nearly always a fixed-wing aircraft) propelled by jet engines. Whereas the engines in propeller-powered aircraft generally achieve their maximum efficiency at much lower speeds and altitudes, jet ...

they were designing must be repairable by an average

mechanic A mechanic is an artisan, skilled tradesperson, or technician who uses tools to build, maintain, or repair machinery, especially cars. Duties Most mechanics specialize in a particular field, such as auto body mechanics, air conditioning an ...

in the field under combat conditions with only these tools. Hence, the "stupid" refers to the relationship between the way things break and the sophistication available to repair them. The acronym has been used by many in the U.S. military, especially the

and

United States Air Force The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Si ...

, and in the field of

software development Software development is the process of conceiving, specifying, designing, programming, documenting, testing, and bug fixing involved in creating and maintaining applications, frameworks, or other software components. Software development invo ...

Variants

The principle most likely finds its origins in similar

minimalist In visual arts, music and other media, minimalism is an art movement that began in post– World War II in Western art, most strongly with American visual arts in the 1960s and early 1970s. Prominent artists associated with minimalism include Do ...

concepts, such as: *

Occam's razor Occam's razor, Ockham's razor, or Ocham's razor ( la, novacula Occami), also known as the principle of parsimony or the law of parsimony ( la, lex parsimoniae), is the problem-solving principle that "entities should not be multiplied beyond neces ...

Leonardo da Vinci Leonardo di ser Piero da Vinci (15 April 14522 May 1519) was an Italian polymath of the High Renaissance who was active as a painter, draughtsman, engineer, scientist, theorist, sculptor, and architect. While his fame initially rested on ...

's "Simplicity is the ultimate sophistication"; *

Shakespeare William Shakespeare ( 26 April 1564 – 23 April 1616) was an English playwright, poet and actor. He is widely regarded as the greatest writer in the English language and the world's pre-eminent dramatist. He is often called England's nation ...

's "Brevity is the soul of wit"; *

Mies van der Rohe Ludwig Mies van der Rohe ( ; ; born Maria Ludwig Michael Mies; March 27, 1886August 17, 1969) was a German-American architect. He was commonly referred to as Mies, his surname. Along with Alvar Aalto, Le Corbusier, Walter Gropius and Frank Lloyd ...

's " Less is more"; *

Bjarne Stroustrup Bjarne Stroustrup (; ; born 30 December 1950) is a Danish computer scientist, most notable for the invention and development of the C++ programming language. As of July 2022, Stroustrup is a professor of Computer Science at Columbia University ...

's "Make Simple Tasks Simple!"; *

Dr. Seuss Theodor Seuss Geisel (;"Seuss"
'' Johan Cruyff Hendrik Johannes Cruijff (, internationally known as Johan Cruyff; 25 April 1947 – 24 March 2016) was a Dutch professional football player and manager. As a player, he won the Ballon d'Or three times, in 1971, 1973 and 1974. Cruyff was a p ...

's "Playing football is very simple but playing simple football is the hardest thing there is"; *

Antoine de Saint Exupéry Antoine is a French given name (from the Latin ''Antonius'' meaning 'highly praise-worthy') that is a variant of Danton, Titouan, D'Anton and Antonin. The name is used in France, Switzerland, Belgium, Canada, West Greenland, Haiti, French Guiana ...

's "It seems that perfection is reached not when there is nothing left to add, but when there is nothing left to take away"; *

Colin Chapman Anthony Colin Bruce Chapman (19 May 1928 – 16 December 1982) was an English design engineer, inventor, and builder in the automotive industry, and founder of Lotus Cars. In 1952 he founded the sports car company Lotus Cars. Chapman ...

, the founder of

Lotus Cars Lotus Cars Limited is a British automotive company headquartered in Norfolk, England which manufactures sports cars and racing cars noted for their light weight and fine handling characteristics. Lotus was previously involved in Formula One ...

, urged his designers to "Simplify, then add lightness"; * Attributed to

Albert Einstein Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theor ...

, although this may be an editor's paraphrase of a lecture he gave., "Make everything as simple as possible, but not simpler". *

Steve Jobs Steven Paul Jobs (February 24, 1955 – October 5, 2011) was an American entrepreneur, industrial designer, media proprietor, and investor. He was the co-founder, chairman, and CEO of Apple; the chairman and majority shareholder of Pixar; ...

's "~~Simplify~~, ~~Simplify~~, Simplify", which simplified

Henry David Thoreau Henry David Thoreau (July 12, 1817May 6, 1862) was an American naturalist, essayist, poet, and philosopher. A leading transcendentalist, he is best known for his book ''Walden'', a reflection upon simple living in natural surroundings, and h ...

's quote “Simplify, simplify, simplify.” for emphasis.

Heath Robinson William Heath Robinson (31 May 1872 – 13 September 1944) was an English cartoonist, illustrator and artist, best known for drawings of whimsically elaborate machines to achieve simple objectives. In the UK, the term "Heath Robinson contr ...

machines and Rube Goldberg's machines, intentionally overly-complex solutions to simple tasks or problems, are humorous examples of "non-KISS" solutions.

Usage

In film animation

Master animator Richard Williams explains the KISS principle in his book '' The Animator's Survival Kit'', and Disney's Nine Old Men write about it in '' Disney Animation: The Illusion of Life'', a considerable work of the genre. The problem faced is that inexperienced animators may "over-animate" in their works, that is, a character may move too much and do too much. Williams urges animators to "KISS".

In software development

Don't repeat yourself "Don't repeat yourself" (DRY) is a principle of software development aimed at reducing repetition of software patterns, replacing it with abstractions or using data normalization to avoid redundancy. The DRY principle is stated as "Every piece of ...

(DRY) *

Minimalism In visual arts, music and other media, minimalism is an art movement that began in post–World War II in Western art, most strongly with American visual arts in the 1960s and early 1970s. Prominent artists associated with minimalism include Do ...

Unix philosophy The Unix philosophy, originated by Ken Thompson, is a set of cultural norms and philosophical approaches to minimalist, modular software development. It is based on the experience of leading developers of the Unix operating system. Early Uni ...

Arch Linux Arch Linux () is an independently developed, x86-64 general-purpose Linux distribution that strives to provide the latest stable versions of most software by following a rolling-release model. The default installation is a minimal base system, ...

* Slackware Linux *

Chartjunk Chartjunk refers to all visual elements in charts and graphs that are not necessary to comprehend the information represented on the graph, or that distract the viewer from this information. Markings and visual elements can be called chartjunk if ...

* List of software development philosophies *

Reduced instruction set computing In computer engineering, a reduced instruction set computer (RISC) is a computer designed to simplify the individual instructions given to the computer to accomplish tasks. Compared to the instructions given to a complex instruction set compu ...

* Rule of least power * There's more than one way to do it *

Worse is better Worse is better (also called the New Jersey style) is a term conceived by Richard P. Gabriel in an essay of the same name to describe the dynamics of software acceptance. It refers to the argument that software quality does not necessarily increa ...

(Less is more) * You aren't gonna need it (YAGNI)

In politics

* Keep It Simple Solutions, New Brunswick, a minor

political party A political party is an organization that coordinates candidates to compete in a particular country's elections. It is common for the members of a party to hold similar ideas about politics, and parties may promote specific ideological or p ...

New Brunswick New Brunswick (french: Nouveau-Brunswick, , locally ) is one of the thirteen provinces and territories of Canada. It is one of the three Maritime provinces and one of the four Atlantic provinces. It is the only province with both English and ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by to ...

* Keep It Straight and Simple Party, a minor political party in

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...

References

External links

Kiss Principle

{{Design Adages Software development philosophies Programming principles Simple living Design