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OODA Loop: Observe, Orient, Decide, Act

All models are wrong, some models are useful.

George E. P. Box

“Observe, Orient, Decide, Act” (OODA) is a simple decision-making model developed by US Air Force Colonel John Boyd. The concept is straightforward: Every entity in a competition is executing these four phases, the side that can execute them more quickly and accurately 1 will win. “OODA” is a useful shorthand for discussing human decision-making and is commonly used in military circles.

Of course, this simple phrase masks an enormous amount of complexity regarding the amount of information observed, the participant’s ability to orient, the quality of decision-making, and the actions available to execute. It is this simplicity that gives the phrase its strength. Because the model is so simple, it is true at every scale: engagement to engagement, battle to battle, campaign to campaign. Strategic decision-makers are looking at the forest while tactical decision-makers are looking at the trees, yet they’re all executing an OODA loop for their relative scope and scale.

Military-industrial complex

The phrase “military-industrial complex” was coined by President Eisenhower in his farewell address to the nation in 19611. In this address, Eisenhower spoke of the deterrence value of military strength:

A vital element in keeping the peace is our military establishment. Our arms must be mighty, ready for instant action, so that no potential aggressor may be tempted to risk his own destruction.

Simultaneously, he warned of the potential danger in the growing relationship between the military establishment and the defense industry:

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The term ergonomics was coined by Wojciech Jastrzębowski in 1857 to mean “the science of work”1 with the goal of improving productivity and profit. He described the importance of physical, emotional, entertainment, and rational aspects of the labor and employee experience, but the context was squarely on factory-type production.

Over time, this has evolved into two, slightly different definitions.

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Human Factors Engineering (HFE)

Human factors engineering (HFE) is a broad and multidisciplinary field that designs and evaluates the human interfaces of a system.

Don’t stop reading — that definition masks a lot of complexity. Let’s break it down:


INCOSE defines system as “an arrangement of parts or elements that together exhibit behaviour or meaning that the individual constituents do not. Systems can be either physical or conceptual, or a combination of both.”

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User Experience (UX)

The term user experience was coined in 1993 by Don Norman while working at Apple. He intended it to encompass a person’s entire experience related to a product, from any feelings they had prior to using it, to first seeing it in the store, getting it home, turning it on and learning how to use it, telling someone else about it, etc.

I highly recommend this short video where Mr. Norman explains this history and also complains about the frequent misuse of the word:

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Materiel, more commonly matériel in US English

Wikipedia entry on “Materiel”

Materiel comes from the French, hence the accented e (which, despite the dictionary definitions cited by Wikipedia, isn’t commonly used in practice). Do a something search for the term and you’ll get a googol1 of results comparing the definitions of materiel and material, but nothing to help the curious engineer or budding acquisition professional understand the practical usage of the term.

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