An Architecture-Centric Process

After an organization agrees on a representation of the architecture that is suitable for the problem at hand, the next issue is to master an architectural design process.

The Rational Unified Process defines two primary artifacts related to architecture:

• The software architecture description (SAD), which describes the architectural views relevant to the project

• The architectural prototype, which serves to validate the architecture and serves as the baseline for the rest of the development

These two key artifacts are the roots of three others:

• Design guidelines are shaped by some of the architectural choices made and reflect the use of patterns and idioms.

• The product structure in the development environment is based on the implementation view.

• The team structure is based on the structure of the implementation view.

The Rational Unified Process defines a Role: Software Architect, who is responsible for the architecture. Architects, however, are not the only ones concerned with the architecture. Many team members are involved in the definition and the implementation of the architecture, especially during the elaboration phase:

• Designers focus on architecturally significant classes and mechanisms rather than on the details of the classes.

• Integrators integrate major software components, even if their implementation is very rudimentary, to verify the interfaces. Integrators focus mainly on removing integration risks related to major off-the-shelf or reused components .

• Testers test the architectural prototype for performance and robustness.

During the construction phase, the focus shifts to adding the meat and skin to the architectural skeleton. Activities reflect an ongoing concern for the architecture: tuning it, refining it, and making sure that no new design decision is introduced that would weaken or break it.

The bulk of the activities related to architectural design are described in the analysis and design discipline (see Chapter 10), but it spills over to the requirements discipline, the implementation discipline, and the project management discipline.