Simulation Settings

Open Model Inspector > Model Settings with no object selected.

Time

• Time Mode selects numeric, calendar, or date-oriented time entry where available.
• Time Unit labels model time, such as seconds, months, or years.
• Start Time / Stop Time define the simulation interval.
• DT is the integration time step. Fractional entry can express DT as a fraction.

Smaller DT can improve numerical resolution but increases sample count and run time. DT must be positive and appropriate for the fastest meaningful change in the model.

Integration

Integration Method selects the numerical method used to update stocks. Changing the method or DT can change results, especially in stiff, oscillating, or rapidly changing models. Treat convergence across smaller DT values as a modelling check.

Run timing

Sim Duration controls the intended wall-clock duration of an animated run. Set it to 0 to run as fast as the native engine can complete. It does not change model time or equations.

Enable Advance Mode to run the model in increments. Advance Time must be at least DT and divisible by DT.

Diagram Mode

Diagram Mode supports qualitative diagrams and disables per-variable simulation behavior. Turn it off before expecting equations to run.

Validation

Before simulation, use Validate Model and resolve missing equations, invalid references, inconsistent connectors, or invalid settings. The Simulate button remains unavailable when the model cannot run.

See Run controls and Model Inspector.