About Message Start Events
A Message Start Event starts a process by receiving a message that conforms to the document type associated with the Message Start Event.
Tip: You can convert a None Start Event to a Message Start Event by dragging a document from the Registry Explorer, Package Navigator, or Search view, and dropping it onto a None Start Event. The Message Start Event is automatically associated with the document dragged to the step.
If you drag a Message Start Event onto an Abstract, Service, User, or Rule task activity, or onto a Call Activity, it is added to the activity step as a non-interrupting Boundary Message Intermediate Event.
Software AG Designer extends BPMN functionality to support the use of EDA event types and the EDA protocol in BPMN Message Events.