Simulation Event dialog box

Use the Simulation Event dialog box to specify the triggers for different events that can occur during a simulation, and the actions to be performed when the event occurs.

Note: Simulation Events don't occur when you're in Stella Live or doing Sensitivity simulations or optimization.

Event Parameters

Specify when an event should occur (be triggered) by giving a threshold and direction.

Threshold specifies the value that the variable must exceed, or drop less than, for an event to occur. If the variable is exactly equal to the specified threshold, nothing happens.

Note: If the variable value exceeds or falls short of the threshold at the beginning of the run, it won't trigger an event. It must cross the threshold before any action will be taken.

Event Type determines whether the event occurs when the value of the variable is greater than or less than the threshold.

• When the variable grows larger than the threshold, if checked, means events will be triggered when values exceed the threshold.
• When the variable drops below the threshold, if checked, means events will be triggered when values are less than the threshold.

Pause option determines whether the triggering of the event will pause the simulation, or if the simulation will continue until it is finished or something else pauses it. Check this box (the default) to have the simulation pause when the event occurs.

Note Even when pause is selected the event will only pause the simulation if there is an action associated with it in the context the run was started. So interface events will never cause a pause when simulating from the model's run toolbar.

Perform each action determines how many times an event will trigger.

• Once per run (each run starts with the first action), if checked, will cause each of the specified actions to be executed at most once during a run, even if the threshold condition suggests it should occur again after all actions have been executed.
• Once Only, if checked, will cause the specified actions to be executed at most once without regard to starting new runs. This is most useful for Interface events, as most model editing will cause this to reset and display messages again.
• On every occurrence of the event, if checked, will cause the specified actions to be executed every time the event occurs, repeating the last action as necessary. A new run will start with the first action.
  • Repeat Every, if checked, will cause an action to occur after the specified interval, if the variable value continues to be on the triggering side of the threshold. The last action will be repeated as necessary.

Event Actions

An event can have a number of actions associated with it. Each time the event triggers, one action will be performed. Should the number of events triggered exceed the number of actions specified, the last action will be repeated.

Actions are specified separately for the model and interface, and this is done in the definition of the action. You can have both types of actions for an event, if you want.

Add Action will open the Simulation Event Action dialog and allow you to define an action. When you click OK on that dialog, the action you've defined will be added to one of the two lists of actions, depending on your selection in that dialog.

Model Actions and Interface Actions are completely parallel. The two labels will only appear if you're using Stella Architect. Otherwise, there will be a single list representing interface actions (if you're using Stella Designer) or model actions (if you are using Stella Professional).

• Edit Action will open the Simulation Event Action dialog and allow you to modify the selected action, including changing between interface and model actions.
• Remove Action will delete the selected action.