Model Settings

There a number of settings the you can set to configure how your model behaves when you run the simulation. The two most important ones are the Time Units, Time Step and the Time Length.

• Time Units: this option specifies what units your model uses. They can be "seconds", "days", "years", or a number of other options.
• Time Length: the time length defines how long the simulation will run for. This is model time, not real time! So if you set the time length for 1,000 years, you won't have to wait until the next millennium to see the results.
• Time Step: this parameter defines how fine-grained the simulation analysis is. You can think of it like this: imagine you were carrying out a scientific experiment where you were keeping track of the weather in one spot over the course of a year. If the data was not very important to you, you could measure the temperature once a month (a time step of 1 month). But if the data was very important, you might measure it every 15 minutes (a time step of 15 minutes). Short time steps lead to more work (and slower simulations) but they generate better results. Choosing a good time step is a trade-off between how long you have to wait for the simulation to complete and the precision of the analysis.

You may set additional parameters of the model simulation including the solution algorithm and several programatic blocks of code. Most often, you will not need to change these parameters from their defaults. The one you will most likely need to set is the solution algorithm and we have prepared a complete help page dealing solely with the available options. The programatic code blocks are areas where you can enter custom Visual Basic Code that is executed at the specified points during the model simulation.