Vensim DSS’s application language and DLLs enable construction of interfaces and packaged applications for learning environments and model distribution.
A Vensim application — or Venapp — can be constructed to provide a Management Flight Simulator or Learning Environment for a model. This allows individuals with little or no training in modeling to get meaningful access to a model. A Venapp combines a model with customized menu driven screens that you design and build, providing an interface appropriate for your target audience. Venapp interfaces can display sketches and use view menu commands to manipulate sketches. Venapp input controls for changing model constants include editing boxes, list boxes, sliders, radio buttons, and checkboxes.
Venapps can be constructed in a text editor or a graphical editor similar to the sketch editor. This supports cut and paste so you can quickly recreate screens or similar elements.
Venapps can perform most simulation functions including sensitivity simulations and optimization. Vensim analysis tools can be accessed to display model structure and simulation output behavior. Games, executive information systems, management flight simulators and scenario builders no longer need to be a black box, but can be investigated through Causal Tracing and other analysis tools to provide understanding on what has happened, and why. Venapps are written in a simple scripting language, and soon a graphical interface builder will be released to speed development.
Custom Applications and the Vensim DLL
The Vensim DLL comes with Vensim DSS and allows you to control models from other applications such as Visual Basic, C, C++, Visual C++, Delphi, Excel, and multimedia authoring tools. The DLL allows you to access a Vensim model from your custom-built applications: send data to Vensim, simulate a model, make changes to model parameters, and collect the simulation data for display. You can also call Vensim’s tools for analyzing and displaying information in the application. For example, you might wish to create an Excel spreadsheet in which you enter data, send this data to a Vensim model for simulation, take the results of the simulation and put them back into the spreadsheet for display (in tables or graphs) or for further manipulation. Another example would be the creation of a customized management flight simulator in a programming language, using the Vensim DLL as the simulation engine, and Visual Basic for the control, display, and perhaps multimedia presentation of information.
Vensim Model Reader
The Vensim Model Reader allows people without Vensim to view and run published models and Venapps for free. Details on the process for doing this are contained in the Vensim DSS Reference Supplement.
Ventana Systems UK Ltd. — Sable
Developed by Ventana Systems UK Ltd., Sable is a programming environment used in creating application interfaces for Vensim, similar to the Venapp builder. Sable has a number of features which make it unique and useful. You can program interfaces that run over intranets or the internet.
Forio’s online service makes it easy to deploy models on the web. Read More