In BPMN one use of Intermediate Events is to represent exception or compensation handling. This will be shown by placing an intermediate event on the boundary of an activity (task or sub-process, either collapsed or expanded). For example, in the following diagram the "Moderate E-mail Discussion" task has an intermediate timer event attached to its boundary that will function as a trigger for the "Review Status of Discussion" task.
For further information on attached events, see topic "Attach Elements to Process Steps" in QPR Modeling Client - User's Guide.
