System Dynamics
From WikiSD
While there are many elevator pitch definitions for System Dynamics, System Dynamics is a rigorous methodolgy employing the development and use of formal computer models that:
- Apply the accepted system dynamics theory of structure (endogenous behavior, feedback loops, accumulations and delays, representation of decision-making);
- Are constructed following the scientific method (reference mode of problem behavior, dynamic hypothesis, formal model, testing of the hypothesis against data, extensive analysis, and policy design); and
- Use best practice tools and techniques (system dynamics software, units checking, standard formulations, generic models and building blocks, graphical functions, etc.).
These three components collectively define rigorous system dynamics. Further, in real world applications:
- Models should be developed so as to achieve client confidence and acceptance (using various approaches including “group model building”).
System Dynamics is not:
- Stella modeling or Vensim modeling (i.e., any model that uses “system dynamics software,” for example only as a programming, graphing or spreadsheet application without system dynamics theory or method.);
- nor is it “systems thinking” (i.e., qualitative modeling uninformed by quantitative modeling).
While software packages and the tools of feedback systems thinking (causal diagrams, archetypes, mental simulation) are used in System Dynamics, they are only tools to help develop, use, and explain the results of formal computer models. This is not to suggest that people should not “do” systems thinking, or use the software for whatever they like; nor is it a suggestion there is not value in their uses; it's just not System Dynamics.
This piece was adapted from Developing a Society Stragety to Promote Growth of the Field, the Presidential Address given by James M. Lyneis at the 2008 Systems Dynamics Society Conference in Athens, Greece.
References
- Bellinger, G. R. 2009. System Dynamics
- System Dynamics The Creative Learning Exchange
- What is System Dynamics Center for Interdisciplinary Excellence in System Dynamics
- Williams, B. & B. Harris. 2005. System Dynamics Methodology
Other Definitions of System Dynamics
- See also What is System Dynamics? on the System Dynamics Society's web site.
- A definition which includes some historical background is available at the International Institute for Applied Systems Analysis as: What is System Dynamics?
- Link to the Wikipedia topic System Dynamics
