Viable System Agent
The Viable System Agent, or VSA is a software implementation of the
Viable System Model
a model for autonomous systems developed by Stafford Beer. The VSA
provides structure, communications, auditing and alerting as defined
in the VSM. The VSA is intended to facilitate creating and managing
autonomous software systems. Think of the VSA as common
instrumentation and communications for autonomous agents. There is a
on some of the goals and terminology of the project. There is also an
with additional information.
The source code
and its comments are available for
The model classes are in Smalltalk, along with unit tests. Most of the
work has been on the autonomics in systems 1, 2 and 3. They are
presently available only as API's. There is no user interface, beyond
the Squeak and Pharo development environments. See how to create VSA
objects and run their methods in these example
The unit tests all pass in Squeak 4.4 and Pharo 2.0, along with a
number of earlier versions of both Squeak and Pharo.
The current version of the VSA has a number of basic Viable System
Model (VSM) features. Software classes for systems 1-5 have been
implemented. The VSM arithmetic for productivity, latency and
performance is done. System 3 has some basic auditing capabilities for
monitoring its subordinate operations. Simple delta (algedonic)
alerting has been implemented. Inter-system communications between the
1-5 systems has been implemented.
A history mechanism was added that can keep a record of actuality,
capability and potentiality over time. System 3 has the capability to
"snapshot" its collection of operations and send the copy to system
4. System 4 can take this copy and run a simulated version of the
system to aid in determining potentiality.
How to get it
You may add the VSA and examples via Monticello using the following
The VSA, documentation and example applications are released under the
- Beer, Stafford. The Heart of Enterprise (1979). Chichester: John Wiley & Sons.
- Beer, Stafford. Brain of the Firm (2nd ed./1981). Chichester: John Wiley & Sons.
- Bayne, Jay S. Cyberspatial Mechanics, IEEE Transactions on Systems, Man, and Cybernetics-part b: Cybernetics, Vol. 38, No. 3, June 2008. IEEE.
- Block, F., Cottle, S., Murray, R. Graham and Dodd's Security Analysis (5th ed./1988). New York: McGraw-Hill Inc.
- Harrison, P. J., and Stevens, C. F., 'A Bayesian Approach to Short-term Forecasting', Operational Research Quarterly, 22, No. 4. December 1971.
- Harrison, P. J., and Stevens, C. F., 'Bayesian Forecasting', Journal of the Royal Statistical Society, Series B (Methodological), 38, No.3, 1976.
- Herring, Charles E. The Viable System Model for Software (2000). Brisbane, Australia: University of Queensland.
- Herring, Charles E. The Pattern of the Viable System and its Language (2001). Brisbane, Australia: University of Queensland.
- Herring, Charles E. Groove: A Case Study in Adaptive Architecture (2001). Brisbane, Australia: University of Queensland.
- McMillan, Lawrence G. Options as a Strategic Investment (4th ed./2002). New York: New York Institute of Finance.
- Medina, Eden. Cybernetic Revolutionaries: Technology and Politics in Allende's Chile (2011). Boston, Massachusetts: The MIT Press.
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