Error opening older SD models in published works (Macintosh vmf files)

[jpain3]

Some colleagues and I have been looking at 'classic' system dynamics models that were published in a variety of journals, including Management Science. In doing so, we've come across at least one issue reading these models that were originally published over a decade ago.

Specifically, the supporting model for "Getting Big Too Fast: Strategic Dynamics with Increasing Returns and Bounded Rationality" in Management Science (https://pubsonline.informs.org/doi/supp ... .1060.0673) appears to no longer be readable by modern software.

The supporting VMF file referenced in the supporting material can be found on John Sterman's old scripts site: https://web.mit.edu/jsterman/www/BLC.html

The supporting file (found in a zipped file here: https://web.mit.edu/jsterman/www/Sterma ... lModel.zip) yields the error "Unable to convert old Macintosh format files-save as .mdl".

Presumably when Sterman and Henderson got this article published in Management Science in 2007, this supporting model was readable using the free Vensim Viewer, as referenced in the supporting material. What changed?

As this is a binary file, I can't diagnose any issues in a text editor, and using other tools (including Stella's converter) imply the file is corrupted.

Are these older models lost to time now, or is there a method of reading these on modern machines?

[Administrator]

I'm sure we can recover the contents of the file, even if we resort to a very old copy of Vensim.

I'll check with John that it's ok to do, and if he says yes, I'll upload the model to the forum.

[tomfid]

This must predate Apple reversing its approach to big/little endian byte order.

I was able to open it in 6.4, but it runs with an error.

In the meantime, my similar replication is here:
https://metasd.com/2010/03/behavioral-a ... -strategy/

This copy is from an earlier version of the paper, but should be pretty much interchangeable.

Tom