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A system is self-sustaining (or self-sufficient) if it can maintain itself by independent effort. The system self-sustainability is:

  1. the degree at which the system can sustain itself without external support
  2. the fraction of time in which the system is self-sustaining

Self-sustainability is considered one of the "ilities" and is closely related to sustainability and availability. In the economics literature, a system that has the quality of being self-sustaining is also referred to as an autarky.

Formal definition[edit]

  1. Let be a random variable that denotes the steady state number of external entities on which the system depends. Let be the probability that the system depends on external entities, . Then, the system self-sustainability, , is .
  2. Let be the expected time during which the system is self-sustaining from time 0 up to time . Then, the system self-sustainability is the steady state fraction of time in which it is self-sustaining,


Political states[edit]

Autarky exists whenever an entity can survive or continue its activities without external assistance. Autarky is not necessarily economic. For example, a military autarky would be a state that could defend itself without help from another country.


According to the Department of Labor of the state of Idaho, an employed adult shall be considered self-sufficient if the family income exceeds 200% of the Office of Management and Budget poverty income level guidelines.[1]

Peer-to-peer swarming[edit]

In peer-to-peer swarming systems, a swarm is self-sustaining if all the blocks of its files are available among peers (excluding seeds and publishers).[2]


Self-sustainability and survivability[edit]

Whereas self-sustainability is a quality of one’s independence, survivability applies to the future maintainability of one’s self-sustainability and indeed one’s existence. Many believe that more self-sustainability guarantees a higher degree of survivability. But just as many oppose this, arguing that it is not self-sustainability that is essential for survivability, but on the contrary specialization and thus dependence.[3]

Consider the first two examples presented above. Among countries, commercial treats are as important as self-sustainability. An autarky is usually inefficient. Among people, social ties have been shown to be correlated to happiness and success as much as self-sustainability.[4]

Notes and references[edit]

  1. ^ IDAHO Department of Labor (1999). "Definition of Self-sufficiency." Retrieved on 2010-06-26.
  2. ^ Menasche, Rocha, de Souza e Silva, Leao, Towsley, Venkataramani (2010). "Estimating self-sustainability in peer-to-peer swarming systems" Retrieved on 2010-06-26.
  3. ^ What and Who is Self-Sufficient? by Katrien Vander Straeten
  4. ^ Social Networks in Plain English on YouTube

See also[edit]