Architecture Modeling - SPES 2020

Architecture Modeling
Depending on the system under development and on the respective development process,
the palette of actually used perspectives and elements may be different for each abstraction
level. In early design stages for example, when the functions of the system are to be defined,
the target platform (modelled in the technical perspective later on) might not be of interest.
This is reflected in the meta-model by allowing to aggregate the set of Perspectives from
an AbstractionLevel, that is considered relevant in that specific abstraction level (see
Figure 3.4).
3.2.1 Operational Perspective
Models of the operational perspective express the operational capabilities and activities that
are expected by the users and customers from the actors and their operational interaction. The
purpose is to identify the customer needs as one of the first steps towards a conrete functional
system design that fulfills these needs. This can be achieved by identifying actors and the
activities being intended to be performed. Scenarios describe the interaction between the actors
and their performed activities. This first analysis of system scenarios helps in determining the
functional needs of the system in subsequent design steps.
OperationalActor
RichComponent
Requirement
+ rationale: String [0..*]
OperationalActiv ity SystemRequirement
+aspect
SystemArtefact Aspect
0..*
+stakeholder
0..*
Stakeholder
Figure 3.5: Meta-model integration of the concepts for specifying the operational perspective
Figure 3.5 depicts the concepts of the meta-model for specifying the operational perspective.
As a first step to capture operational functionality the meta-model specification concept
of OperationalActivity can be used to model an operational activity. Being specialized
RichComponents their dynamics can be abstracted by means of contracts. The concept of
contracts is named SystemRequirement in the meta-model for reasons explained in Section
3.3.1.3. Actors that perform these activities can be modeled as OperationalActors
taking part in the scenario. Since in the beginning of the design process the concrete system
under design and its boundary are unknown in later refinement steps these actors of a scenario
performing operational activities can be realized by the system under design and its environment.
In [35] an approach to model-based requirements engineering is proposed, which includes
a process description how system scenarios can be derived from system goals. Note that the
concept of goals proposed in that approach is not part of the current version of the architecture
meta-model. However they may eventually be referenced by the rationale attribute of the
Requirement concept.
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