Service Interaction Patterns
However, there are several differences between
process orchestrations and process choreographies that need specific consideration:
choreographies are based on message exchange, and potentially many
participants interact in a choreography, while orchestrations are based on
control flow between the activities of a single process performed by a single
Service interaction patterns aim at filling this gap by proposing small granular
types of interactions that can be combined to process choreographies. As
with control flow patterns for process orchestrations, service interaction patterns
can also be used to benchmark languages for their ability to express
advanced conversations. Service interaction patterns can be classified according
to the following schemes.
• Number of participants involved: Bilateral interactions involve two participants,
whereas multilateral interactions involve more than two participants.
• Number of messages exchanged: Single transmission versus multi-transmission
• Variations in message receiver : In case of two-way interactions, round-trip
interaction means that the receiver of the message is necessarily the same
as the sender, whereas routed interaction means that the receiver of the
message in general differs from the sender.
The Business Process Modeling Notation is used to provide graphical representations
of service interaction patterns. Since this notation is not specifically
tailored to the needs of service interaction patterns, the graphical representations
of the patterns are not complete. Together with the textual representation
of the patterns, the service interaction patterns are described properly.