A Rationale-based Model for Architecture Design Reasoning

6.6. A UML representation of AREL and eAREL
Figure 6.10 shows the ≪AR≫ and ≪AAR≫ stereotypes. Their implementation is
built on the UML Package meta class. ≪AR≫ and ≪AAR≫ both contain a ≪QLR≫
and a ≪QNR≫, where ≪QLR≫ and ≪QNR≫ contain the attributes that characterise
the architecture rationale (see Section 6.4 for details of the attributes). An AR can
contain zero or more AAR depending on the number of discarded design alternatives. If
there is no design alternative, then there is no instance of an AAR. The containment of
all relevant design rationale within an AR reduces the complexity in traceability without
compromising the information it contains.
Figure 6.10: ≪AR≫ and ≪AAR≫ Stereotypes
The stereotype ≪AAR≫ provides a template to document alternative architecture
designs that have been discarded. Since an AAR contains the element Alternative Model,
which is implemented as a ≪package≫, it can contain UML constructs such as use case,
class diagrams, artifact, object or other UML diagrams. Architects can retain any documentation
about the discarded design in the Alternative Model that might be useful.
6.6.3 The architecture trace stereotype
In Definition 1, we provide a directional causal dependency for tracing the links in AREL.
We implement these links by a UML association stereotype ≪ARtrace≫. The direction
100