A semantically complete description of a system.
See also package, subsystem.
A model is an abstraction of a system from a particular viewpoint. It describes the system or entity at the chosen level of precision and viewpoint. Different models provide more-or-less independent viewpoints that can be manipulated separately.
A model may comprise a containment hierarchy of packages in which the top-level package corresponds to the entire system. The contents of a model are the transitive closure of its containment (ownership) relationships from top-level packages to model elements.
A model may also include relevant parts of the system's environment, represented, for example, by actors and their interfaces. In particular, the relationship ...