A typical scenario is where a transaction traverses the enterprise from application to application in order to complete the entire business transaction.
The entire flow often starts from an order in a GUI or from B2B, triggering a whole set of transactions through the enterprise.
The orchestration required for the transaction can be done in the ESB. In this case it becomes separate scenario: Event Orchestration (SC-EPO), solved by the pattern A2PESB (for simple cases) and by EPOAPP or A2PBPM for more complex cases.
The application knows exactly what to send to which other system for each type of transaction, and functionally requires verification that the message arrived and was processed correctly in the target.
Each leg from the orchestrating application to other systems are examples of Event-Driven Transactional interfaces.
Speed requirements are moderate (~< 10s). Volumes are low (< 1/s), and message size is small (<1Mb).