A Rationale-based Model for Architecture Design Reasoning

6.6. A UML representation of AREL and eAREL
Figure 6.9: ≪AE≫ Stereotype to extend Architecture Drivers
To model the business viewpoint that contains requirements, environmental factors,
constraints and assumptions, we use the ≪AE≫ stereotype to extend UML model elements
Class, Object, Artifacts and Use Case. These extended UML model elements as
shown in Figure 6.9 can create architecture models in different architecture viewpoints.
For instance, a Use Case can capture system interaction, and Artifacts and Objects can
capture requirements and constraints in the Business Viewpoint.
Architecture design elements that are represented by the Data Viewpoint, Application
Viewpoint and Technology Viewpoint as shown in Figure 6.4 also use the ≪AE≫
stereotype to extend their UML meta classes. The UML design elements that have been
extended include Class, Object, Package, Component, Artifact, Table and Deployment;
and behavioural diagrams that have been extended are Use Case, Communication Diagram,
Analysis Diagram, Activity Diagram, State Chart and Sequence Diagram. With the
stereotyping, these UML constructs can capture the additional information as shown in
Figure 6.9.
6.6.2 The architecture rationale stereotype
AR is implemented by a UML stereotype, denoted by ≪AR≫, to extend the Package
metaclass. It contains a number of attributes:
• arID is the unique identifier of an instance of AR.
• currFlag is a boolean flag to indicate whether the AR instance records a current or
superseded rationale. Only the latest version of a decision has a truth value.
• lastUpdateDateTime - date and time of last modification.
• author - name(s) of the decision maker(s).
99