Selected Models to Download
You can construct most of the models in the 2nd edition of the book based on the description in each chapter.
This page provides downloadable files for models that are not easily constructed from the information in the book.
 The Stella models are posted in two formats: the 1st is *.stm format. The 2nd uses the *.stmx format.
Notes on Stella & Vensim software are at the bottom of the page.
Additional models (for instructors only) are posted in the Instructors' portion of the BWeb.
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Salmon Harvesting Models
Salmon Simulator (p 203): 1st Stella model, 2nd Stella model
Salmon Simulator model with Vensim PLE

Daisyworld Design Challenge
Daisyworld Simulator (p 134, Fig 11-9. 1st Stella model, 2nd Stella model
Daisyworld (to test span of control) -- Vensim model

Electric Vehicles, Air Pollution and Feebate Management

Feebate Management Model (p 218, Fig 16-4) 1st Stella model, 2nd Stella model
Feebate model (operate in SyntheSim mode) --- Vensim model
Market share calculation on page 216 --- Excel Spreadsheet

River Basin Planning
Separate page for the Idagon Stella models shown on p 13, 156 of 2nd Edition, Apx K of 1st edition

The Pesticide DDT in the Environment
These models are described in Chapter 12 of the 1st edition.
They are explained more briefly in Chapter 22 of the 2nd edition.
Separate page for DDT exercises and stella equations for DDT models
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Software Notes

Stella: Ver 3-9 Users:
The Stella models in the book were created years ago and saved as *.stm files.
If you use stella Ver 3 - Ver 9,  it will recognize the *.stm files on the website.

Stella:  Ver 10 + Users:
If you use Stella Ver 10 or higher, it expects *.stmx files.
However, it will recognize the *.stm files as an earlier version.
It will then ask you if you would like the older model to be saved as a *.stmx file.
You can agree to this change and then use the model as explained in the book.

Stella:  Architect & Professional Users:
Two recent programs from isee systems  are Stella Professional and Stella Architect.
These programs can read *.stmx models, but they will not understand *.stm models.

Vensim: Some students see gibberish when they click directly on the link to a Vensim model.
This may happen when your operating system opens the model in the text mode.
Downloading works better if you click on the BWeb link and ask to save the model to your modeling folder.
Then open the Vensim program; click on File/Open Model; then slect the just-saved file in your folder.

Previously Posted:  Previous versions of the BWeb posted web based models using NETSIM software.
NETSIM is no longer supported by isee systems, so these models are no longer posted.
Also, the salmon smolts migration model from the 1st edition of the book is no longer posted here.
(1st edition readers are encouraged to move to the 2nd edition.)