Ventity Beta Available

The public beta of Ventity, new simulation software, is now available – we’ve just uploaded the latest (build 573). Get it at

Ventity is new simulation software for complex systems. Key benefits include:

  • Modularity and object orientation, supporting sectors and complex agents, without arcane arrays
  • Dynamic creation and deletion of model components and relationships
  • Support for team collaboration, model federation and submodels
  • Advanced graphics and a new, clean look
  • Just like Vensim, a pure declarative language (no programming)

The most important change is that we’ve replaced arrays with lists of entities, identified by attributes. This confers several advantages. Detail becomes a property of entities, not equations, which makes it a lot easier to change. Entities are modular, so they’re easier to reuse and share among teams. Entities can be created and deleted dynamically, so there’s no need to simulate a lot of zeroes for things that haven’t happened yet. Similarly, a list can represent a sparse matrix, so there’s no need to clutter your model with zeroes for project phases that aren’t prerequisites or relationships that don’t exist among people. All this happens in a development environment with modern graphics and windowing.

Here’s a real-world example that’s just come up. A consumer products firm would like to model a portfolio of products across many regional markets, distribution channels, brands and package sizes. Not all of the brands are present in each market, and package options differ for each brand. We’ve done this many times in Vensim, but it takes a lot of data work to standardize things to work with arrays. With entities, it’ll be easy – we’ll create a Product entity identified by Market, Channel, Brand and Package attributes, and we simply won’t bother to create combinations that don’t exist. Later, when new products launch, we can add them to the model on the fly.

We think we’re just scratching the surface of what’s possible. That said, there are still some things that Vensim is really good at, like extreme speed, advanced algorithms and data connectivity, so we’re continuing its development in parallel. We’ve been working on infrastructure for 64bit and Mac builds lately, which puts us on a solid footing for future upgrades. Ventity doesn’t replace Vensim; we will continue to develop the two products in parallel, with complementary feature sets and interoperability where possible. Ventity licensing for existing Vensim Pro and DSS users will be favorable.


You can watch a Ventity preview here.There’s a Ventity poster and more detailed white paper in the SD conference proceedings:

The Help system contains a lot of good “getting started” material, including a series of videos, which are also on Vimeo, starting with:

The Ventity support forum is up and running at: