<< Click to Display Table of Contents >> Navigation:  Defining Entity Types > Importing Vensim Models

 

Currently Ventity has a basic capability for import of Vensim models. It generally works very well for simple models and "clean" subscripted models.

 

The first thing to keep in mind is that importing a Vensim model can only be done into an empty Ventity model, so Ventity will prompt you to pick a save location for the newly-created Ventity model. Once you’ve decided on a location for the new, imported model to be saved, navigate to File and select Import Vensim Model. Navigate to the model you’d like to import, and select Open.

Note that if you’re only interested in importing a portion of a Vensim model into Ventity, you could import the whole model via the Vensim Import tool and then create a single Entity to contain the elements of the Vensim model you’re interested in. Or, copy-paste the Vensim structure into a new Vensim model, define placeholder values (like 0) for any boundary variables, and save as a new .mdl. Then import the resulting Entity into your original Ventity model.

       

Ventity will automatically add all of the stocks, flows, variables and tables from the Vensim model, and these will all appear on the Entity Inspector of the newly created Entity.

From this inspector, you can then recreate the diagram. It's typically best to start by dragging the flows from the inspector onto the diagram to create the stock-flow "main chains."

You can now either manually move the auxiliaries from the Entity Inspector on to the diagram, or you can select the stocks and flows and individually right-click on missing auxiliaries and select “Draw Arrow from [auxiliary name]” to automatically add and connect the auxiliary on the diagram. Once all of the elements of the model are in place, diagnosing any remaining issues should become much easier. For simpler models, it is possible to run Ventity immediately after importing a Vensim model, as even without the diagram set up all of the links, connections and relevant equations still exist. However, since much of the error reporting is tied to elements on the diagram, diagnosing problems becomes much easier with the diagram fully (or even partially) built prior to running the model.

 

The following video covers import in greater depth: