International Encyclopedia of Systems and Cybernetics

2nd Edition, as published by Charles François 2004 Presented by the Bertalanffy Center for the Study of Systems Science Vienna for public access.


The International Encyclopedia of Systems and Cybernetics was first edited and published by the system scientist Charles François in 1997. The online version that is provided here was based on the 2nd edition in 2004. It was uploaded and gifted to the center by ASC president Michael Lissack in 2019; the BCSSS purchased the rights for the re-publication of this volume in 200?. In 2018, the original editor expressed his wish to pass on the stewardship over the maintenance and further development of the encyclopedia to the Bertalanffy Center. In the future, the BCSSS seeks to further develop the encyclopedia by open collaboration within the systems sciences. Until the center has found and been able to implement an adequate technical solution for this, the static website is made accessible for the benefit of public scholarship and education.



1. Repetition of elements in a message or system which permits to circumvent transmission errors or functional failures.

2. A measure of how much knowledge about parts of the system allows to know something about other parts, due to known constraints between them (H. ATLAN, 1989)

3. "…the number and variety of internal subsystems which can perform the same function equally well" (W.D. GROSSMANN & K.E.F. WATT, 1992, p.10).

In relation to the first definition, it should be noted, in M. MARUYAMA's words that: "If a message can be compressed shorter by an efficient coding, then the amount of space saved by the compression is called redundancy" (1992, p.196).

This is the original meaning given to the term by C. SHANNON in his theory of communication. Redundancy here is used to compensate noise and to maintain reliability in the communication process. K. KRIPPENDORFF states: "English writing is estimated to be 50% redundant which account for the ability of native speakers to detect and correct typing errors" (1986, p.64). Redundancy is also useful for reconstruction of mutilated messages.

As to W.D. GROSSMANN and K.E.F. WATT they state: "Redundancy… provides reserves" (Ibid., p.8). In this case, failure of one circuit or channel can be compensated and reliable systems constructed from somewhat unreliable parts (von Neumann).

If redundancy, in ATLAN's opinion, reflects constraints, or the organization of the system, it is however obvious that an excessively redundant system (i.e. very constrained one) cannot have much functional meaning and, if totally redundant, none at all.

This is why "one finds also variety or diversity as a property typical of the existence of an organization, especially when complex adaptative behavior is exhibited. This property is in fact opposed to the first one (i.e. Redundancy) and it is a measure of the uncertainty or unexpectedness of the so-called information content of a system, in the formalism of information theory. As such it can be used to measure the complexity of a natural organization" (1989).

Thus, any complex system needs simultaneously variety and redundancy, which are in some sense complementary.

When the system ages, its redundancy diminishes, while its variety grows, up to a limit which is a characteristic of the system. The construction of variety uses up redundancy.


  • 1) General information
  • 2) Methodology or model
  • 3) Epistemology, ontology and semantics
  • 4) Human sciences
  • 5) Discipline oriented


Bertalanffy Center for the Study of Systems Science(2020).

To cite this page, please use the following information:

Bertalanffy Center for the Study of Systems Science (2020). Title of the entry. In Charles François (Ed.), International Encyclopedia of Systems and Cybernetics (2). Retrieved from www.systemspedia.org/[full/url]

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