The event queue, accessible via transaction SWEQADM is an all important subject with a high "need-to-know-about" factor. It queues events and makes sure these events do get triggered in the sequence they were queued. The event queue will capture peak workflow processing and limit it's (potentially very damaging) effect - when your event does not have to be triggered immediately - put it on the queue.
How ? Events can be set to use the queue per linkage, so when an event is used to trigger 2 workflows and stop a third workflow, the queue can be set up 3 times. Use transaction SWETYPV and find your linkage. Alternatively (for triggering events) the event queue usage can be switched on in transaction PFTC tab triggering events, select the event and click on the "puzzle button (ICON_DETAIL)".