A System Zoo

I just picked up a copy of Hartmut Bossel’s excellent System Zoo 1, which I’d seen years ago in German, but only recently discovered in English. This is the first of a series of books on modeling – it covers simple systems (integration, exponential growth and decay), logistic growth and variants, oscillations and chaos, and some interesting engineering systems (heat flow, gliders searching for thermals). These are high quality models, with units that balance, well-documented by the book. Every one I’ve tried runs in Vensim PLE so they’re great for teaching.

I haven’t had a chance to work my way through the System Zoo 2 (natural systems – climate, ecosystems, resources) and System Zoo 3 (economy, society, development), but I’m pretty confident that they’re equally interesting.

You can get the models for all three books, in English, from the Uni Kassel Center for Environmental Systems Research – it’s now easy to find a .zip archive of the zoo models for the whole series, in Vensim .mdl format, on CESR’s home page: www2.cesr.de/downloads.

To tantalize you, here are some images of model output from Zoo 1. First, a phase map of a bistable oscillator, which was so interesting that I built one with my kids, using legos and neodymium magnets:

A glider searching for thermals:

Chaos in the Roessler system:

Have fun.

4 thoughts on “A System Zoo”

  1. I’m working my way through Systems Zoo 1 this week – this is such a good overview of classic system physics, every SD student should have access to this!

    1. That’s it, but for some reason the direct link doesn’t work for me – the server seems to want us to follow the Download >> Software links to find the zip manually. Anyway, they are great.

  2. Here is a simple way to get all the System Zoo models:
    Call up “Google”, enter “www2.cesr.de/downloads”.
    The homepage of the CESR Center for Environmental Systems Research in Kassel/Germany will appear. Under
    “SYSTEM ZOO Simulation Models” select the
    “ZOO_MDL.zip” archive.
    Enjoy your visit to the System Zoo!
    Hartmut Bossel

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.