When your simulation involves simultaneous events whose causality relationships do not determine a unique correct processing sequence, you might have a choice regarding their processing sequence. These tips can help you make appropriate choices:
Several blocks offer a Resolve simultaneous signal updates according to event priority option. The default value, which depends on the block, is appropriate in most simulation contexts. Consider using the default value unless you have a specific reason to change it.
If you need explicit control over the sequencing of specific kinds of simultaneous events, assign numerical event priorities for events that you want to defer until after other events are processed. For procedures and tips related to numerical event priorities, see Assign Event Priorities.
In some debugging situations, it is useful to see whether the simulation behavior changes when you either change the value of a block's Resolve simultaneous signal updates according to event priority option or use an extreme value for an event priority. Experiments like this can help you determine which events might be sensitive to changes in the processing sequence. The debugger can also help you detect sensitivities.