Running an Optimization

GoldSim provides the ability to carry out a special type of run to facilitate optimization of your model. For this type of run, you specify an objective function (a specific result that you would like to minimize or maximize), an optional constraint (a condition that must be met), and one or more optimization variables (variables in your model that you have control over).

GoldSim then runs the model multiple times, systematically selecting combinations of values for each of the optimization variables. By doing so, GoldSim can determine the values of the optimization variables that optimize (minimize or maximize) the objective function while meeting the specified constraint.

Typical uses of optimization include:

• Finding the best input data values for a model, in order to match observed historical data (i.e., calibration).
• Selecting the "best" option from among alternatives. "Best" could mean safest, cheapest, most reliable, or another appropriate measure.
• Optimizing the timing of actions or policy changes during the course of a simulation.

The details of how to set up and run an optimization are presented in the topics below.

Two optimization examples can be found in the General Examples/Running folder in your GoldSim directory (accessed by selecting File | Open Example... from the main menu): 1) a very simple example file which illustrates the use of optimization for the purpose of calibration (CalibrationOptimization.gsm); and 2) a fairly complex example that illustrates the use of optimization to optimize a design (DesignOptimization.gsm).