CPSA Quality Attributes and Scenarios 4 — Questions and Answers
Question 1: In iSAQB quality scenario structure, the 'artifact' refers to:
- A deliverable produced during the sprint
- The specific part of the system (component, module, or whole system) that is stimulated (Correct answer)
- The person who evaluates the system's quality
- The metric used to measure success
Correct answer: The specific part of the system (component, module, or whole system) that is stimulated
The artifact identifies which part of the system the scenario applies to, such as a specific service, database, or the entire system.
Question 2: A system that degrades gracefully under overload by shedding non-critical requests is exhibiting which quality attribute?
- Fault tolerance (sub-characteristic of Reliability) (Correct answer)
- Portability
- Learnability
- Co-existence
Correct answer: Fault tolerance (sub-characteristic of Reliability)
Fault tolerance means the system continues operating, possibly in a degraded mode, in the presence of faults or overload conditions.
Question 3: Which quality characteristic in ISO 25010 includes 'appropriateness recognizability', 'learnability', and 'user error protection'?
- Compatibility
- Maintainability
- Usability (Correct answer)
- Reliability
Correct answer: Usability
Usability in ISO 25010 encompasses sub-characteristics related to how effectively and satisfactorily users can interact with the system.
Question 4: Which statement about quality attribute trade-offs is TRUE?
- Security and performance never conflict
- Increasing reliability always improves maintainability
- High security measures can negatively impact performance and usability (Correct answer)
- Portability and testability always improve together
Correct answer: High security measures can negatively impact performance and usability
Security controls such as encryption and authentication add overhead, which can increase latency and reduce system usability.
Question 5: A 'general scenario' for availability would look like:
- The payment service recovers within 30 seconds after a database crash during business hours
- An external actor causes a fault; the system continues operating in degraded or full mode within a specified time (Correct answer)
- Users can access the system 99.99% of the time measured monthly
- The DevOps team restores the system backup within 4 hours
Correct answer: An external actor causes a fault; the system continues operating in degraded or full mode within a specified time
General scenarios use abstract, non-system-specific language to describe the pattern, while concrete scenarios fill in the specifics.
Question 6: Which of the following is a sub-characteristic of Maintainability in ISO 25010?
- Recoverability
- Modularity (Correct answer)
- Fault tolerance
- Time behaviour
Correct answer: Modularity
Modularity is a Maintainability sub-characteristic reflecting the degree to which a system is composed of discrete components that minimizes the impact of changes.
Question 7: When stakeholders say 'the system must be secure', an architect should FIRST:
- Implement TLS on all endpoints immediately
- Refine the vague goal into concrete quality scenarios with measurable response measures (Correct answer)
- Add a firewall and document it in the architecture
- Reject the requirement as too broad to implement
Correct answer: Refine the vague goal into concrete quality scenarios with measurable response measures
Vague quality goals must be converted into concrete scenarios with specific stimuli, environments, and measurable response criteria before architecture decisions can be made.
CPSA Quality Attributes and Scenarios 4
In iSAQB quality scenario structure, the 'artifact' refers to: