New !

Vensim 5 is now released.  See the Read Me notes here.

Vensim Simulation Software

Vensim is used for developing, analyzing, and packaging high quality dynamic feedback models.  Models are constructed graphically or in a text editor. Features include dynamic functions, subscripting (arrays), Monte Carlo sensitivity analysis, optimization, data handling, application interfaces, and much more.  Ventana Systems also provides the Molecules software, for constructing system dynamics models from "chunks" or molecules of system dynamics structure.

Comparison Chart for different Vensim configurations

Documentation available on this website

Vensim PLE

Vensim PLE Plus

Vensim PLE Plus bridges the gap between the inexpensive (or free) PLE and our higher configurations.  PLE Plus is fully featured for its price point and includes data connectivity, multiple views, Monte Carlo sensitivity simulations, game simulations, and the new model-user interface (Input and Output Controls).  PLE Plus can be purchased by credit card on our secure sever.

Vensim Professional, and DSS

Read the Vensim Brochure.  Vensim Professional is what is needed for managing large and mode complicated models. It provides Causal Tracing^TM of structure and behavior, and has Monte Carlo sensitivity, optimization and subscripting (array) capabilities.  Vensim DSS adds an interface development tool for creating management flight simulators, external functions and macros, compiled simulations, and more.

Model Reader

The Vensim Model Reader is free software which allows you to publish models constructed with Vensim and distribute them to other people.  Your model and the Vensim model reader can be copied and passed to as many people as you want, giving people access to your model without their needing to purchase Vensim. 

Demonstration Program

The Vensim Demonstration features a tour of Vensim, includes several models with flight simulator interfaces, and contains the Vensim development environment for modeling, along with some sample models.

Molecules

The Molecules software is used for constructing system dynamics models from "chunks" or molecules of system dynamics structure.  This software is a collaborative effort among a number of authors.

Venapps

Custom Vensim applications (flight simulators and other interfaces to models) can be developed with the Venapp builder, or in a programming language such as Visual Basic, C, C++, Visual C++, Delphi, Excel, and multimedia authoring tools, or in Sable  (below).

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.

Online Documentation

Vensim documentation available online includes installation instructions, Read Me notes, Vensim PLE & PLE Plus User's Guide, and the Molecules guide.

Technical Highlights

Vensim contains many industry-leading technical advances in continuous simulation technology.  Read more about:

	Causal Tracing™
	Subscripting
	Optimization
	Venapp Flight Simulators (Learning Environments)
	Resource Allocation algorithm (ALLOC P)

Computer Hardware Requirements

The Vensim family of software runs on Windows 98/NT/2000/XP/Vista/7. Vensim is a 32 bit progam  but will run fine on 64 bit versions of Windows. The Macintosh version is curently in Beta and requires OSX version 10.4 or higher. The Windows Version will run on the Macintosh using Crossover, or with a Windows virtual/alternate boot installation. Vensim requires about 20 megabytes of disk space for a full installation and will run with any reasonable amount of memory.  For very large models more memory and disk space will be required as a single run can easily take 100 megabytes of disk space.  Generally it is a good idea to have at least as much memory as the size of the largest .vdf file you are creating. 

History of Vensim

The history of Vensim is here.

Y2K Compliance

Vensim is Y2K compliant.  Click here for more details.