Start Events for Top-level Processes

There are many ways that top-level Processes can be started (instantiated). The trigger for a Start Event is designed to show the general mechanisms that will instantiate that particular Process.

Marker Trigger Description

The None Start Event does not have a defined trigger. There is no specific EventDefinition subclass (see page 259) for None Start Events. If the Start Event has no associated EventDefinition, then the Event MUST be displayed without a marker (see the figure on the right).

  Message A Message arrives from a Participant and triggers the start of the Process. See page 91 for more details on Messages. If there is only one EventDefinition associated with the Start Event and that EventDefinition is of the subclass MessageEventDefinition, then the Event is a Message Start Event and MUST be displayed with an envelope marker (see the figure to the right). The actual Participant from which the Message is received can be identified by connecting the Event to a Participant using a Message Flow within the definitional Collaboration of the Process.
  Timer A specific time-date or a specific cycle (e.g., every Monday at 9am) can be set that will trigger the start of the Process.
  Conditional This type of event is triggered when a condition such as “SP 500 changes by more than 10% since opening,” or “Temperature above 300C” become true.
  Signal A Signal arrives that has been broadcast from another Process and triggers the start of the Process.
  Multiple This means that there are multiple ways of triggering the Process. Only one of them is REQUIRED.
  Parallel Multiple This means that there are multiple triggers REQUIRED before the Process can be instantiated. All of the types of triggers that are listed in the Start Event MUST be triggered before the Process is instantiated.