Starting in Strategy 9.3.1, additional logging is available for Distribution Services. The "Scheduler Details" log is useful when troubleshooting the activity of the Scheduler process regarding event triggering in Distribution Services. The Scheduler process is responsible for constantly checking for newly created subscriptions and notifying the Intelligence Server about when they should be executed.
The trace can be found in the Strategy Diagnostics and Performance Logging tool as shown below:

Note: This trace is not enabled by default. An existing or new "File Log" destination must be selected for this logging to be used.
Anytime an event is triggered, this log will display a summary of the number of schedules found in relation to the triggered event:
2013-12-13 18:42:51.445-05:00 MSIScheduler::ProcessEvent(): 1 schedulers return from GetScheduleTriggers(). 2013-12-20 20:43:59.022-05:00 MSIScheduler::ProcessEvent(): 2 schedulers return from GetScheduleTriggers(). 2013-12-20 20:44:40.920-05:00 MSIScheduler::ProcessEvent(): 2 schedulers return from GetScheduleTriggers().