Reading Supporting Material

Supporting Material files can be found by clicking on the appropriate link in the Paper Index (index.htm) found on the CD proceedings. Papers are listed alphabetically by the last name of the primary author.

      Viewing/Opening/Reading the Supporting Material:

Some of these files are regular texts or presentations which are in widely accessible formats such as .doc, .ppt, .pdf, etc., but others are model files, which need to be viewed using the appropriate system dynamics modeling software. Below, find information on how to access freeware/demo/trial versions from several system dynamics software manufacturers. Follow the links within the descriptions below to the software needed to view the files.

In following chart, find the three-letter extension of the file name, then the software you need to view the file.

File Name Extension

Software Needed

.itm, .stm

ithink, STELLA*


Powersim Studio



.vmf, .mdl


*ithink and STELLA can each be used to open both .itm and .stm files.

STELLA/ithink by isee systems (formerly High Performance Systems):

This link will navigate you to the FREE isee Player. The isee Player lets you view, run, print and share both STELLA and iThink models. Available in both Windows and Macintosh versions, the isee Player allows exploration of all model layers - map, model, equation, and interface, and never "times out."

Powersim Studio by Powersim Solutions:

Powersim Studio Express is a 60-day trial version of Powersim Studio 2005. Note that this installation will automatically replace any previous version of Studio 2000, 2001 or 2003 that is installed on the computer. Studio 2005 can open files from earlier versions of Studio, but earlier versions cannot open a file that has been updated or created in Studio 2005. Studio 2005 contains an array of new and exciting features, including tools for optimization and risk analysis, number formatting, new user assistance features, the ability to customize the user interface, and more.

Vensim by Ventana Systems:

The Vensim Model Reader can be used to open Vensim models which are files with extension .vmf. This is free software which will allow you to view and simulate models changing the assumptions but not model structure. Many models (both .vmf and .mdl) can also be opened using Vensim PLE which is free for educational use. Both are available from: