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.



The combination of two well known systemic approaches for the analysis of complex problem situations, namely P.B. CHECKLAND's Soft Systems Methodology and J. FORRESTER's Systems Dynamics.

SSDM has been introduced by R. RODRIGUEZ ULLOA, President of the Instituto Andino de Sistemas (Lima. Peru), who states that "It was felt that Systems Dynamics did not answer very clearly (the following) vital questions:

- Under which world-view are the causal loops constructed which show the (specific) phenomena occuring in the real-world?

- Who are the observers and why do they observe the real-world the way they do?

- Do human affairs and natural phenomena existing in the real-world behave under a "logical" and "rational" way i.e.: Is it possible to delineate a logical framework of how real world phenomena behave?), or on the contrary, is it not possible because they behave in an "irrational" and unsuspected way?

(Note: "rationality" can be only in the eye of the beholder. The "rationality" of the armament industry for instance is not the same as the "rationality" of sustainable development, or of environmental care)

- If there is an "irrationality" in the behavior of the real-world 's phenomena, which is the "rationality" that supports it?

- Is it possible then to model that "irrationality" under a schema which is based on a causeeffect rationality?

- Which are the reasons under which an observer choses a particular way of seeing a specific problem-situation?

Which kind of interests and values push them to observe the real-world in that way?

- How can someone give a "solution" about something, if the "problem" has not been clearly understood or if the consciousness of the world-view under which it is being observed is neglected (or ignored)?

- Is the "solution" provided by the Systems Dynamics approach culturally feasible and systemically desirable?

- What learning points can be obtained from constructing Systems Dynamics models and implement them in the real-world?" (R. RODRIGUEZ-ULLOA, 1999)

It is to be noted that Systems Dynamics proposes answers to "What if"s hypotheses, applied to a pre-established model of the problem-world, sometimes constructed on very shaky observational and epistemological ground, but nevertheless uncritically used (FORRESTER's warnings notwithstanding!).

Accordingly, and to complement these question marks, the author establishes an ontological, epistemological and philosophical comparison matrix between Soft System Methodology, Systems dynamics and the emerging Soft Systems Dynamics Methodology. This latter includes and compatibilizes all the important features of SSM and SD.

Catwoe; Clanthink; Design; Groupthink; Underconceptualization

An overview of the Soft Systems Dynamics Methodology

RODRIGUEZ ULLOA describes the stages to be followed in applying the SSDM

- Stage 1: Description of the problem situation in its un-structured form.

- Stage 2: Creation of a "rich picture" of the situation by incorporation of important aspects frequently neglected as related to "problem-owners, clients, actors, their worldview, level and kind of power, their relationships, etc." (Ibid)

- Stage 3: Introduction of "problem-oriented root definitions", which can be used "in order to describe epistemologically… "irrationalities". Under this perspective "root definitions are used to express problematic transformation processes, instead of expressing transformation processes oriented to provide "solutions" to the problematic situation… "

- Stage 4: Building dynamic models of the "problematic situation". At this stage "a problematic context diagram of the situation is built up". Of course, this context diagram responds to the particular Weltanschauung (i.e. worldview) that the observer has emphasized in a particular problematic root definition. Changes in the root definition originate changes in problematic context diagram and viceversa"

- Stage 5: Comparison of the systems dynamics models against the rich picture built at stage 2. This is a process of validation of the models, tending to verify if "the model expresses adequately what is happening in the real – world"

- Stage 6: Determinate feasible and desirable changes. This means mainly "culturally feasible" and "systemically desirable" (i.e., excluding any self-contradictory specific or global action or effect).

- Stage 7 Building dynamic models of the "Solving Situation". This step is needed because no satisfactory evaluation of the models is to be obtained without future projections of the possible consequences of their application.

- Stage 8: Express the transformation process needed to perform "improvements" of the problematic situation. If "some difficulties appear at this stage, due to systemically undesirable factors, then some adjustments are needed between stages 2 and 7, until a "good" adjustment is found"

- Stage 9: Implant feasible and desirable changes in the real-world This should not be done before reaching a satisfactory validation of the models.

- Stage 10: Collect all learning points and save them for future study and reflection. "The learning points come from the sensitivity analysis of modelling the "problematic situation" as well as the "solving situation" and the proper implementation action in the real-world (Stage 9)

A graphical representation of SSDM (given by the author) is very helpful for a better understanding, in particular because the feedbacks among the different stages are fully graphicated.

RODRIGUEZ ULLOA's paper provides a quite complete glossary of the terms used in SSDM

Catwoe; Design (Generic); Soft Systems Methodology; Systems Dynamics.


  • 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]

We thank the following partners for making the open access of this volume possible: