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4.2 Architectural Views
Views are used during the design and implementation phase of a concrete
system architecture. They are defined in the following way:
“A view is a representation of one or more structural aspects of an architecture
that illustrates how the architecture addresses one or more concerns held by
one or more of its stakeholders.” [Rozanski 2011]
A view is composed of viewpoints, which aggregate several architectural
concepts in order to make the work with views easier. The IEEE standard 1471
defines viewpoints as follows:
“A viewpoint is a collection of patterns, templates, and conventions for
constructing one type of view. It defines the stakeholders whose concerns are
reflected in the viewpoint and the guidelines, principles, and template models
for constructing its views.“ [IEEE Architecture]
Some typical examples for viewpoints are
Functional view: functional-decomposition viewpoint; interaction
viewpoint; interface viewpoint; Information view: information-hierarchy viewpoint; semantics viewpoint;
information-processing viewpoint; information-flow viewpoint.4.2.1 Usage of Views and Perspectives in the IoT RA
As mentioned in the introduction to this chapter, the IoT Reference Architecture
is use-case- and application- independent and is therefore not compatible to the
concept of views and viewpoints one-by-one. But the idea behind the concept is
nevertheless helpful and was thus adopted for the use within the IoT Reference
Architecture. As discussed above the following views were left out from the IoT
Reference Architecture but are discussed in Section 5.2:
Physical-Entity View; Context View.Concerning the Functional View, of the above three viewpoints, interactions are
not covered in the IoT Reference Architecture, since the number of
arrangements of the Functional Components and also their invocation is
practically infinite. Instead, we chose to cover some typical –but yet high-level-
interaction patterns in the Guidelines chapter (see Section 5.2.10).
The same is true for the deployment and operational View. However, there are
aspects to both that are practically invariant over the IoT domain and these
aspects are covered in Section 4.2.4. Also, what is an aspect of the deployment