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Ventana are proud to sponsor the System Dynamics conference on our 41st birthday.
We are a group of System Dynamics practitioners with diverse interests in energy, infrastructure, logistics, project management, health and a variety of other fields. We also publish the Vensim and Ventity software, used worldwide for building models. We make versions of Vensim and Ventity available free for learners.
Ventana helps clients solve hard problems in strategy, operations, marketing and public policy. We integrate models and data to provide insights that machine learning and systems thinking alone can’t access. These pages give some examples of our work and describe our approach.
https://www.ventanasystems.com
Vensim is an industry standard simulation tool, enabling large models with extreme speed and serious data management, at the center of a large ecosystem, and supporting education with free PLE:
https://www.vensim.com
Ventity is a new hybrid modeling tool, with a natural data architecture, dynamic creation of new entities, sparse network support, and elegant graphics:
https://www.ventity.biz
What’s New?
Try out these interactive analyses enabled by rapid web publishing and AI agent support. More to come at our Sponsor Demo.
Schedule
Several of us will be on site this year. Want to learn more about Ventana, Vensim or Ventity? Visit our booth anytime, or catch our Sponsor Demo session and workshops.
See the ISDC 2026 schedule for full details.
July 14 (Tue)
Workshop: Introduction to Vensim (Virtual)
Workshop: Introduction to Ventity – from Classic SD to DES, ABM and Networks
We understand that the society had some problems with web registration and time zones – if you missed these, recordings and materials are available in the workshops section below.
July 22 (Wed)
Meeting 10:00 (327): Sponsor Demo: Ventana Systems, Inc. (Hybrid), chaired by Tony Kennedy – highlighting Vensim & Ventity
July 23 (Thu)
- Table Talk 13:00 (263): Policies and Progress (In-person), chaired by Nikola Pucarevic
- A Technique for Estimating the Progress of System Dynamics, by David Peterson, Matthias Otto Mueller Abstract
July 24 (Fri)
Workshop 13:30 (176): Unified Web Deployment of Vensim and Ventity Models (Hybrid), chaired by Adem Delibas, Tony Kennedy (TPM Hall C)
Workshop 15:30 (175): Using AI Agents with Vensim and Ventity (Hybrid), chaired by Tom Fiddaman, Tony Kennedy (TPM Hall C)
Ventana Systems is thrilled to be leading the opening session at the upcoming Systems Practice Forum 2026, hosted by the MIT Alumni community!
Special 8:30-18:00 (349): Systems Practice Forum 2026 (Hybrid), chaired by Steven Smith (Senaatszaal)
Software
Vensim
Vensim PLE – free for educational and personal learning use, including the workshop. You can always download a copy at https://vensim.com/free-download/. After the conference, we ask that commercial and government users purchase an inexpensive license for continued use beyond workshops and software evaluation.
Vensim DSS Trial – you can get a fully functioning trial version of Vensim DSS by completing the following form.
Ventity
You can download a copy from https://ventity.biz/download/ and request an evaluation license using the form. Note that Ventity requires Windows 10 or 11. People have used Mac emulators successfully. After downloading, educational users can request a free academic license.
Workshop Materials
2026 Workshops
When you arrive, you will want to have Vensim or Ventity pre-installed on your computer (see links in the software section above), to avoid delays or surprises.
Bring a laptop, or share with a friend, or just watch. Models and materials are posted to these archives:
Introduction to Vensim, Introduction to Ventity
Download this to a convenient unlocked location on your hard drive and unzip.
Ventity workshop participants: we’re unable to replicate the blank model overview some of you observed for the sample models in this .zip. We now speculate that the cause is opening the models from the .zip directly, without first unzipping. That would cause the entity files in a Ventity project to fail to load, because they’re not adjacent to the primary .vmdl.
Recordings
Unified Web Deployment of Vensim and Ventity Models
Ventity 6 isn’t out yet (release after the conference), so to try this hands-on you’ll want Vensim DSS 10.5.2 installed (trial license provided at the link).
Download this to a convenient unlocked location on your hard drive and unzip.
Using AI Agents with Vensim and Ventity
Ventity 6 isn’t out yet (release after the conference), so to try this hands-on you’ll want Vensim DSS 10.5.2 installed (trial license provided at the link).
Then you’ll need:
- The VenAgent, VensimMCP and VentityMCP package (Windows .zip or Mac .dmg)
- Python 3.10 or higher (be sure to include it in your system environment path when you install)
- A terminal AI agent like Claude Code CLI (also in your path)
- Mac users may need to brew install uv
Stuck? Ask your AI agent to help – they’re good at configuration tasks.
2025 Workshops
Bring a laptop, or share with a friend. Models and materials are posted to these archives:
Intro to SD + Bathtub Statistics 2025.zip
VENTITY intro patient ISDC25.zip
The materials should be copied to a convenient unlocked location on your drive and unzipped.
When you arrive, you will want to have Vensim or Ventity pre-installed on your computer (see links in the software section above), to avoid delays or surprises.
2024 Workshops
Models and materials are posted to this archive: VensimVentitySharedMaterials2024.zip.
When you arrive, you will want to have Vensim or Ventity pre-installed on your computer (see links in the software section above), to avoid delays or surprises.
The materials should be copied to a convenient unlocked location on your drive and unzipped.
Introduction to Vensim
Introduction to Ventity & Model Reuse
2022 Workshops
In 2022 we prerecorded all of our workshop content, so that it’s available to everyone, not just in-person conference attendees, all the time.
Introduction to Vensim
Finished models from this video: EX Customer Base.zip
Slides: Introduction to System Dynamics.pdf
This version has really been superseded by the edition above, but if you’re using an older version of Vensim (<v10) you may find the interface more familiar.
Using Data in Vensim
This video walks you through most of the pathways for using time series data in Vensim. You’ll need Vensim PLE+, Pro or DSS for most of this – if you don’t have a copy, you can use the trial link above.
Models & Slides: VensimData
Vensim Calibration – Part 1
This video walks you through the essence of the calibration process, from creating synthetic data (for “real” data, see the previous workshop) to an initial, simple calibration.
Slides and start/finish models: CalibrationWithVensim2022 pt1.pdf CalibrationWithVensim2022 pt2.vdf VensimCalibration – PredatorPrey.zip
Vensim Calibration – Part 2
This video picks up where Part 1 ends, and covers advanced topics – weighting the payoff, Kalman fitering, using Markov Chain Monte Carlo for confidence bounds, sensitivity analysis, and priors for Bayesian System Dynamics.
Slides and start/finish models (same as above for Part 1): CalibrationWithVensim2022 pt1.pdf CalibrationWithVensim2022 pt2.vdf VensimCalibration – PredatorPrey.zip
Introduction to Ventity with Agents
This video introduces you to Ventity with an interesting agent-based model.
For a quicker introduction, you might also be interested in Doing Classic SD with Ventity