Ventana was founded in 1985 to apply modern techniques of simulation and data analysis to problems in business, economics and engineering. To learn to make realistic models of businesses and markets, the founders of Ventana studied at MIT under Professor Jay W. Forrester. To test and calibrate the models, they studied under MIT Professor Fred C. Schweppe, who developed some of the key algorithms for making deductions about complex systems using incomplete and inaccurate data.

Ventana extended the work of Forrester and Schweppe, combining realistic models with the ability to evaluate the quality of information. Ventana contributions include software for efficient building of models; and automated testing to understand their veracity before relying on them. The purpose of the models is to anticipate the consequences of actions, e.g. policies or investments, with the goal to make companies and governments sustainable.

Ventana sells two state-of-the-art simulation environments. Vensim enables the efficient building, testing, calibrating and optimization of dynamic simulation models (for example, for a company, market, industry, or economy). Vensim was originally developed for internal use, and still is influenced by the needs of client projects. Ventana made Vensim available commercially in 1991, and continues to add features. Over one million copies have been downloaded. A version of Vensim is provided free of charge for educational use.

Ventity, Ventana’s new agent-based modeling environment, provides an object-oriented view of a system. Ventity was created to make realistic representations of economies and markets as composed of interacting individuals and groups. Ventity also supports discrete events and meshes with relational databases.