FIGURE 2-27
A system context element.
bdd [package] System context element [section]
Customer
Reservation system Central locking system
?«system?»
On-board
computer
?«systemContext?»
On-board computer
context
61 2.3 Modeling the System Context
Table 2.8 Summary: Identifying system interaction points.
Reference card: Identify system interaction points.
Incoming and outdoing data
System context:
System with associated actors.
System context [interaction points]:
System with interaction points.
Motivation/description
Why? Interaction points describe the interfaces to the system environment and are
responsible for successful system integration.
What? Describe the points of your system over which information will be exchanged
with the environment.
How? Think about a relevant interaction point for each actor. Bear in mind that one
single point could be used by several actors.
Where? The interaction points will then be specifi ed in more detail in the design.
Guiding questions
?– What paths will the system use to exchange information with its environment?
?– Are your interaction points conceptual or physical?
?– What interaction paths for actors can be merged?
SysML elements
Block defi nition diagram, internal block diagram, block, actor, association, role,
connector, standard port.
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