System Dynamics

Models Illustrating System Dynamics Modeling in GoldSim

Although GoldSim is similar to system dynamics programs in many ways (and can simulate any kind of system that these tools can), GoldSim moves beyond the relatively restrictive stock and flow syntax in order to more realistically model complex systems.

The models listed below illustrate the use of GoldSim for classic system dynamics problems.

You can filter the list by entering keywords or phrases into the search field:

• Population Dynamics and Chaos

This model illustrates perhaps the most famous example of chaotic behavior: that exhibited by the ´logistic difference´ equation to describe the growth of a population subject to a carrying capacity.

• Mono Lake Water Balance

Water balance model illustrating a negative feedback loop and of the use of scenarios with a dashboard

• Mono Lake Water Balance Player Model

Player model to illustrate differences in dashboards and scenarios between Player and GoldSim

• Pressure, Productivity and Quality

Example model illustrating feedback from pressure and fatigue on productivity and quality

• Population Growth Aging Chain

Example model illustrating population dynamics modeling with Discrete Change elements and Integrator arrays

• Polya Urn Problem

This simple model simulates the classic Polya urn problem in which stones, either black or white, are randomly selected (with replacement and addition) from a pot.

• Adoption and Diffusion of Technology

A logistic growth curve model is employed to simulate the adoption and diffusion of a new idea or technology

• Predator-Prey Models

This example implements several predator-prey models taken from "Modeling the Environment" by Andrew Ford.

• Simple Inventory Models

This model file includes 5 variations on a simple inventory model. In each case, there is an initial inventory, a sinusoidal demand and a production rate that is constant, stochastic or influenced by feedback.

• Auto Supply Chain Model

This is a demonstration model of an automobile supply chain. It represents two links in the chain: the OEM and a major tier 1 supplier (in this case, power trains).

• Salmon Life Cycle

This is a simple model that simulates the life cycle of a salmon population as it migrates from the stream, to the ocean, and back to the stream. Although the data and model structure are fictional, it does provide a simple example of how such a model could be constructed.

• Dove, Hawk, Law-Abider Populations

This is a model of the population dynamics of three groups adopting dove, hawk and law-abider strategies.

• Acute Infection Model

These two models (continuous and discrete) simulate the spread of an acute infection through a population

• Inventory Management

A simple inventory management model that illustrates the structural differences between how such a model is constructed in GoldSim, and how it would be constructed using a classic System Dynamics code.