10.2. Quality Scenarios

Concretization of (sometimes vague or implicit) quality requirements using (quality) scenarios.

These scenarios describe what should happen when a stimulus arrives at the system.

For architects, two kinds of scenarios are important:

• Usage scenarios (also called application scenarios or use case scenarios) describe the system’s runtime reaction to a certain stimulus. This also includes scenarios that describe the system’s efficiency or performance. Example: The system reacts to a user’s request within one second.

• Change scenarios describe a modification of the system or of its immediate environment. Example: Additional functionality is implemented or requirements for a quality attribute change.