Exhibit 14.22 illustrates a star logical design composition style, in which the international
news agency service cluster transmits news to four subscribers: homeland security news portal
consumer, technology journal portal consumer, business news portal consumer, and auto magazine
portal consumer. Note the four various supporting star beams and their unidirectional relationships.
This operation is known as the fire-and-forget message transmission model (akin to multicasting)
in which the message originator party does not expect acknowledgement or returned results.
So how can a star composition style that is depicted in the logical design composition
diagram be represented in a transaction activity diagram? In Exhibit 14.23 at the very center
of the depicted single transaction, the international news agency service cluster broadcasts four
different news notifications to its four subscribers: technology journal portal, homeland security
news portal, auto magazine portal, and business news portal. This is illustrated as a single transaction
in which all activities operate in parallel without waiting for each other (the timeline for
each service-oriented asset is omitted, and the concurrency flag is grayed out). These depicted
activities are also identified as choreographed operations because the message exchange and service
collaboration take place between organizations and do not occur on the application level.
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