Architecture Modeling - SPES 2020

3.2.2 Functional Perspective
Architecture Modeling
Modeling the functional perspective of the system serves identifying the functional needs of the
system. Derived from an analysis of the operational context of the system in the Operational
Perspective, its behavior is specified from a user-centric point of view, establishing a blackboxview
of the functions of the system. Subsequently these top-level functions are refined by
sub-functions that together realize the top-level system functionality. Ideally, functions are
completely independent of any architecture.
Elements of an operational model defined at the same or a higher abstraction level can be
allocated on the defined functions. This way, the contribution of a function to an activity of
an actor can be explicated, which allows to investigate whether each activity is supported by
system-functions, and whether the design goals can be accomplished.
+part 0..*
RichComponentProperty
+component 1
+type
«isOfT ype» 1
RichComponent
Function
+aspect
SystemArtefact Aspect
Requirement
+ rationale: String [0..*]
SystemRequirement
0..*
+stakeholder
0..*
Stakeholder
Figure 3.6: Meta-model integration of the concepts for specifying the functional perspective
The architecture meta-model provides the concept of a Function (see Figure 3.6) to model
functions of the system. Function is a specialized RichComponent and thus can have
behavior. Inputs and outputs of a function are represented by ports. Functional as well as
non-functional specifications are defined and assigned to the modelled functions by means of
SystemRequirements (contracts).
3.2.3 Logical Perspective
The logical perspective constitutes the decomposition of a system into reusable components
and specifies their interaction. Additionally, the environment is modelled with respect to the
interfaces of the system, which includes both syntactical interfaces and behavioral interaction.
That way, the logical parts of the system and their relationships are identified. Technical aspects
and choices of any technology are typically not considered in the logical perspective. The
logical perspective is the entry to the design of the system. Functions modelled within the
functional perspective can be spread across the defined logical components.
Logical components of a system are modelled by the architecture meta-model concept
LogicalComponent (see Figure 3.7). LogicalComponent is a specialized
RichComponent, and thus can have behavior. Ports typed by PortSpecifications
specify the interaction points of the component. Functional as well as non-functional requirements
can be formulated as SystemRequirements. A LogicalComponent can
be instantiated in a given context of other component instantiations by using the concept
RichComponentProperty. The behavior of the component instance is determined by its
type.
The concepts EnvironmentComponent models a component of the environment interacting
with the System. Conceptionally an actor is also part of the environment.
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