Dynamo equation in vensim

[alvinpoon]

Dear

I try to replicate the customer produces employment case study model in the book of Industrial dynamics by Jay Forrester. I think this is interesting and challenging job.

I face question.how to convert attached 2 dynamo formula into vensim equation format.

I.copy the two equations in attached. Can vensim expert help.advice what would be the equations written in vensim?

Thank you

[Administrator]

Have you tried doing this yourself yet? I don't see anything tin those equations that cannot be done in Vensim.

[tomfid]

I remember those 1-e^x formulations.

There's a replication of the Ch. 15 version of Industrial Dynamics is in my library here: https://metasd.com/2010/03/industrial-dynamics/

If you go further than that, it would be great to have a copy for the library (be sure to add your name to the credits).

e^x in Vensim is the EXP(x) function. Log_e(x) is LN(x).

[alvinpoon]

Thank you Tom!

I just read thru the Vensim help related to EXP and LN, LOG, really got it as you said

I will share it accordingly later.

[tomfid]

There's one thing I wish I'd done when I did the translation above. The DYNAMO convention at the time limited variable names to 8 letters, case insensitive, like MTR. The documentation contains the explanation (material in transit to retail). When you hover on the diagram, you can see the documentation for each variable, but that doesn't make for a user-friendly diagram. It would be nice to modify all the variable names with the docs, like "MTR material in transit to retail" and then pretty up the diagrams. Preserving the original abbreviation as a prefix makes it easy to cross-reference with the book.