Model Library

This library contains replications of many classic models from system dynamics and related fields. Citations are provided. Unfortunately I don’t know of online resources for most of the articles, but links are provided where possible. MIT theses are now available online through MIT Document Services. Many classic SD publications are available through Leverage Networks and Amazon.

Many of the models in this library were recreated from published works by students in the MIT Sloan School’s PhD Seminar in System Dynamics. Where credit is unknown, thanks should go to Rogelio Oliva, Scott Rockart, Nelson Repenning, Ed Anderson, Liz Krahmer, Hank Taylor, and several other MIT students for the arduous process of reconstructing these models from published sources. Be forewarned that, since most of these models are replications, it’s possible that they contain errors introduced in the publication or reconstruction process.

Generally, the models in this library may be freely used and distributed, subject to authors’ copyright, which should be noted in the model file. Naturally you should acknowledge the hard work of the authors and implementors who created these files.

There are some differences in floating point math between hardware platforms, so you may find differences in output or fp errors I haven’t discovered that occur only on one platform. Many models can be run and edited with Vensim PLE (free); models with arrays, optimization, or other advanced features may be browsed and run with the Vensim Model Reader, but require purchase of Vensim DSS or Pro for editing.

I’m happy to entertain submissions.

Models are under the Model Library categories in the sidebar. Here’s a full list:

• Scientific Revolutions in Ventity
• Escalator Solutions
• The Mysterious TREND Function
• Steady State Growth in SIR & SEIR Models
• A model of COVID-19 in the US with endogenous testing, containment measures, and social distancing
• Vensim SIR modeling primer
• A Community Coronavirus Model for Bozeman
• Dweilen met de kraan open
• S-shaped Functions
• Misadventures with Little’s Law
• Aging Chains and the Erlang Distribution
• Coupled Catastrophes
• Opiod Epidemic Dynamics
• Modeling Investigations
• Biological Dynamics of Stress Response
• Dynamic Cohorts
• The Beer Game
• Polynomials & Interpolating Functions for Decision Rules
• Thyroid Dynamics
• The Dynamics of Initiative Success
• Nelson Rules
• Update to Path Dependence, Competition, and Succession in the Dynamics of Scientific Revolution model
• The Ambiguity of Causal Loop Diagrams and Archetypes
• Dynamics of the last Twinkie
• Job tenure dynamics
• Forrester on Continuous Flows
• Dynamics of Term Limits
• Feedback and project schedule performance
• FREE
• The dynamics of UFO sightings
• Samuelson’s Multiplier Accelerator
• Bulbs banned
• Environmental Homeostasis
• Wonderland
• Early warnings of catastrophe
• Positive feedback drives email list meltdown
• Arab Spring
• Encouraging Moderation
• Spot the health care smokescreen
• Bathtub Statistics sandbox
• Social network valuation with logistic models
• Forest Cover Tipping Points
• Stochastic Processes
• Vensim Model Documentation Tool
• Bifurcations from Strogatz’ Nonlinear Dynamics and Chaos
• Climate Catastrophe
• Gumowski-Mira Attractor
• A Dynamic Synthesis of Basic Macroeconomic Theory
• A note on the bathtub analogy
• The Economic Long Wave
• Economic Cycles: Underlying Causes
• The Dynamics of Commodity Production Cycles
• Lotka-Volterra predator-prey system
• Path Dependence, Competition, and Succession in the Dynamics of Scientific Revolution
• Polya urn with increasing returns
• A System Zoo
• Delay Sandbox
• Theil Statistics
• The Rise and Fall of the Saturday Evening Post
• Boiling Water Reactor Dynamics
• Fibonacci Rabbits
• Poisson distribution demo
• Market Growth
• Oscillation from a purely positive loop
• Bifurcating Salmon
• Urban Dynamics
• DICE
• Java Vensim helper
• Cumulative Normal Distribution
• WORLD3-03
• Payments for Environmental Services
• Models in the Special Issue of the System Dynamics Review on Environmental and Resource Systems
• Rental car stochastic dynamics
• Pink Noise
• Industrial Dynamics
• Lorenz Attractor
• Logistic Chaos
• Heat Trap
• World3 Population Sector
• Ultradian Oscillations of Insulin and Glucose
• Sea Level Rise
• Good Enough Tools
• A Behavioral Analysis of Learning Curve Strategy
• World Dynamics
• The Energy Transition and the Economy
• Comparison of Delays
• Terrorism Dynamics
• Payments for Environmental Services
• Models in the Special Issue of the System Dynamics Review on Environmental and Resource Systems
• The other bathtubs – population