
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.

The purpose of this model is to demonstrate time shifting historic data in a Time Series element. This type of model makes it easy to show summary statistics like exceedance probability of annual peak flow rate or mean annual flow rate.

This model simulates a Markov process that randomly switches between a wet state and a dry state to simulate rainfall given some key historic statistics.

This simple model illustrates how to move discrete items from one state to another.

This simple model shows one method for allocating competing demands on a Reservoir.

This is a model that simulates the performance of a lunar base over its planned 20 year lifespan. It illustrates how GoldSim's Reliability Module can be use to carry out a probabilistic risk assessment of a complex system.

This is a model that simulates an unmanned scientific mission to another planet. It illustrates how GoldSim's Reliability Module can be used to carry out a probabilistic risk assessment of a complex system.

This model shows how reliability elements can be used to model throughput in an oil pumping facility. Pumps are turned on and off as the desired flow rate changes and pumps fail and are repaired.

The GoldSim 11.0 implementation of AWBM for calculating runoff from rainfall on a watershed. This model is used for water yield and water management studies.

Calculate future, monthly water demands based on current usage and an annual projection

Simulate the feedback loop between water sales revenues and funding a conservation program.

This model counts the number of days in which some failure occurs. A failure event is defined as a reservoir overflow occurrence for any duration within a single day.

Simulate the growth of a money market fund plus savings account that represents a college fund. What is the chance of saving enough for your child?

This model includes 4 different methods of time shifting to be used in a wider array of applications.

The purpose of this model is to demonstrate how GoldSim can calculate hydraulic functions dynamically.

This model uses a submodel to estimate a possible shortfall for the coming year in order to set a supply curtailment if needed.

This is a GoldSim impleneation of the NRCS WinSRM model for calculating runoff from a snowmelt driven watershed.

This model demonstrates the use of GoldSim's optimization feature to calibrate a snowmelt model by automatically adjusting parameters to achieve correlation between historic streamflow record and streamflow calculated in the model.

Operating rules control outflows from a reservoir that contains operating zones divided into surcharge, flood control, conservation, and dead pool zones.

Simulate the breach in a dam as it grows through time and the resulting discharge hydrograph

Monte Carlo Simulation of the Dam Breach algorithm to calculate risk of failure

Use GoldSim's scenarios functionality to create a decision support framework for your next project.

The purpose of this model is to demonstrate the use of GoldSim elements to represent a flow network of multiple storage elements that distribute water for water use. Water enters the system via "Inflow_Data".

Simulate the operation of a simple reservoir with an overflow spillway.

This model is based on the Great Falls Project, a series of five hydroelectric dams near Great Falls, Montana.

This simple example simulates the flow between and the levels of a twotank system using Bernoulli's theorem.

Check that inflows, outflows, and changes in storage within your flow model balance.

This model illustrates how you can reference a Time Series like a lookup function to access future or past values.

A History Generator Element is used to model an Itoprocess random walk. The distribution of the future value is lognormal with mean and variance that both increase linearly with time.

Comparison of two alternative technologies accounting for uncertainty and using Scenarios

Computation of building displacement or response to the signal created by earthquake ground motion using a Convolution element

Economic analysis of production expansion stratagies including uncertainty

Simulation of a diving bell released at a specified depth and moving towards the surface where it emerges above the water

The interaction between a reservoir and a large aquifer is simulating using a simple seepage model

Simple model of calculating production losses through a set of three parallel pumps each with failures and repairs

Demonstration of GoldSim optimization capabilities using a simple reservoir and hydropower model

Illustration of logic to keep a specified number of Reliability Module components operating at given times

This is a simulation for an ATM machine installed at an event location, where there are frequent customer visits

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

This model illustrates how several methods for calculating a reservoir discharge can be combined into a single model. The methods includes calculations based on fluid physics, lookup tables and volumetrically under lowlevel conditions.

Simple but realistic water balance model for a mine

Example model providing demonstration of two different priority implementations in an allocator element

Simple mixing chemistry equilibria model which uses lookup tables to link to PHREEQC

Example model showing an approach for calculating the solubility of an element based on equilibrium chemistry

Example of integrating equilibrium chemical processes into GoldSim to represent water treatment for acid mine drainage

Estimation of dynamic lake stratification using a onedimensional model

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

Package of models that allows the user to adjust highway access control measures and view the effect of these measures

Example model illustrating a weir flow calculation for spillway outflow which is limited by available volume for use with long time steps

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

Tutorial model that calculates the probability that Jason can buy a bike given his income and spending

This example combines both continuous and discrete dynamics to model the transport of a material by truck to a dock where the material is loaded onto ships.

This is a simple discrete events model of the number of tellers and the size of a queue of customers at a bank.

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.

Calculation and comparison of three different depreciation methods

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

This example implements several predatorprey models taken from "Modeling the Environment" by Andrew Ford.

Reusable model providing a modified Muskingum hydrologic routing formulation

This model describes heat transfer in a doublepipe heat exchanger operated in countercurrent flow.

This model describes heat transfer in a doublepipe heat exchanger operated in parallel flow.

This model explores 3 different methods of controlling discharge from a reservoir. The difference between these methods is important to understand for models that contain multiple reservoirs where discharge from one is being sent to another.

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.

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).

This simple model can be used to calculate the monthly payment of a fixedrate mortgage.

Commonly used Muskingum hydrologic routing is implemented in GoldSim with Reservoir elements

In this simple model, widgets are processed at a warehouse for 30 days. The widgets arrive at a rate of about once every two hours. It takes a certain amount of time (1.8 hrs) to process each widget and ship it out, and only one widget can be processed at a time.

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.

Watershed runoff is calculated for three catchments using the same function but different inputs

This model demonstrates the use of a Status element to control discharges from a reservoir.

This reliability model illustrates a typical closed circuit grinding mill circuit, used in many mine processing plants.

Forecast water demand for multiple entities based on assumed starting conditions and projected rates of change such as population, water prices, and seasonal use adjustments.

This model simulates ships entering the harbor where each ship carries a random number of containers.

Illustration of a simple mass balance calculation for a flow network for an inert constituent.

This model demonstrates how GoldSim can be used to model fluid flow in a countercurrent flow network.

This model demonstrates how GoldSim can be used to model fluid flow in a parallel flow network

This model simulates the heating of circuit boards with hot air over four minutes.

Three different types of promotional campaigns are compared across a 180 day campaign period.

This model demonstrates a simple continuous stream diversion and and a diversion operating for a fixed amount of time each week.

This model illustrates how to use the Convolution element to compute cumulative warranty costs.

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

This model demonstrates how a user of a dashboard can control currency exchange rates and select which currency to use in a model.

This model prices the value of European (fixed exercise date) call and put options for a stock.

This model provides simulation of nonpoint source pollutant buildup and washoff with automated calibration.

This model presents a pond discharge versus pond capacity optimization problem.

Simulate an aging chain using various methods to keep track of the age structure of a stock of material or items.

This is a simple heat transfer model of a cooling cup of coffee.

This is a model of nitrogen, phytoplankton, zooplankton and dissolved oxygen dynamics in a stratified lake.

This model illustrate how conditional containers can be used to simulate projects.

This model simulates employee supply for a company with complex and lengthy training requirements.

This model simulates the process of obtaining FDA approval for a new drug.

This model provides a native GoldSim implementation of the Hydrological Simulation Program Fortran (HSPF).

This model provides a simple financial simulation of a company.

This model simulates air concentrations of BTEX at a former gas station site.

This model illustrates the simulation of transport and mixing of two contaminants sourced from a spoils heap.

This model illustrates one way in which GoldSim can be used to generate a stochastic precipitation record.

A script element is used to solve for pumping flow as a function of the total dynamic head on the pump due to headloss.

Use the Reliability Module of GoldSim to calculate the failure modes of various components of a pumping station and water delivery system.

Use Markov process to simulate stochastic precipitation events based on a wet state and dry state.

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.

In this example, a SubModel is used to calculate average monthly rainfall amounts from a Time Series element containing rainfall rate data

This example shows how to use a vector constructor to generate a vector of month flow rates for integration and other calculations

This example illustrates an efficient way (using cloned containers) to model multiple objects of the same type without having to manually reimplement identical model logic.

This model describes a manufacturing process with the following stages: (1) casting, (2) prefinish, (3) ‘solution oven’ heat treatment, (4) ‘aging oven’ heat treatment and (5) a finishing process.

This model simulates a slot machine with 3 reels each having 5 images that wins money if you end up with 3 in a row.

Simulating production scenarios to help decide whether to replace or repair a widget production system

This model demonstrates how GoldSim can be used to model heat transfer from a pipeline to the ambient environment.

Simulates filling, operations, and cleaning of septic impoundments after the material is allowed to dry out followed by final disposal at a landfill.

This model provides a native GoldSim implementation of the Hydrological Simulation Program Fortran (HSPF) and divides the watershed into multiple subcatchments.

Exactly the same implementation as the original AWBM except this has added capability to incorporate multiple subcatchments using GoldSim's array label sets.

This model simulates 3 tasks within a project and the associated cost to complete it using conditional containers.

This model incorporates the Scenario Manager to assist with stakeholder evaluations of environmental flow alternatives.

This model allows design of stormwater drainage channels used to convey design flood discharges associated with storm runoff from the catchment.

Using the GoldSim optimization module, a rainfall generator is calibrated using historical data

This model accounts for rainfall recharge when calculating groundwater inflow in a mine pit using the DupuitForchheimer equation.

Simulates the inflow and outflow from a pond that controls discharge using a simple orifice in a riser outlet works

Simulate runoff from multiple subbasins in a watershed using AWBM in GoldSim

Calculate the headloss through this pipe bend and the hydrodynamic force on the pipe

Calculate flow rate over a sharpcrested rectangular weir and check for proper sizing

This static GoldSim model calculates the normal depth in an open channel assuming uniform flow conditions.

This model illustrates how to fit a trend line to data using the GaussNewton method.

Radiological performance assessment (PA) model incorporating many features and processes typical of a PA for a disposal facility for lowlevel radioactive waste (LLW).

Calculate the direct runoff hydrograph using a triangular unit hydrograph and direct precipitation

Use GoldSim to perform a flood frequency analysis of daily streamflow records using the Log Pearson III distribution

Using a submodel, calculate the recurrence interval and exceedence probability of annual reservoir spill events

Calculate the number of years you can withdraw money from a retirement account with interest and inflation

Simple ECommerce, decisionmaking case study using GoldSim "whatif" simulation