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R13 / 1:Mc

Subsystem manages zero, one or many Subsystem Element

Subsystem Element is managed by exactly one Subsystem

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By definition, a Subsystem Element is defined and managed as part of a single Subsystem. This means that all documentation of the Subsystem Element can be found in its managing Subsystem.

Often a Subsystem Element will appear as an import in other Subsystems within the same Domain as a point of reference and often in an abbreviated form. When an imported Subsystem Element is seen outside of its Subsystem, as a dashed rectangle on a diagram, or with an import statement in a text file, for example, the documentation can be found by tracing it back to the managing Subsystem.

A Subsystem can be defined that does not contain any Subsystem Elements, but that Subsystem will have no utility in a running system.