sqm3 Flashcards
(5 cards)
Scenario:
You are assessing a legacy student records system at a university. The vice-chancellor wants updates applied quickly, but your team finds the code poorly structured and undocumented, leading to delays.
a. Using the Internal vs External Quality Model, explain why internal maintainability issues affect external stakeholder satisfaction.
(6 marks)
b. Identify and describe any three internal quality attributes that would directly impact maintainability in this system.
(6 marks)
c. What real-world risks arise if maintainability is low but usability is high?
(3 marks)
a.
Internal issues like poor documentation or tightly coupled code make it harder for developers to locate, test, and release changes → causes delays (external issue). Though users don’t see these directly, their experience is affected (long wait times, buggy updates).
b.
Modularity: Hard to isolate functions
Documentation Quality: Hard to understand how the system works
Code Structure: Poor structure increases risk during edits
c.
Users may love the interface, but future updates may introduce bugs, delays, or regressions. Long-term system reliability suffers.
a. Briefly describe the three McCall model perspectives and give one example each of how they relate to software product quality.
(6 marks)
b. How does the McCall model’s internal focus differ from models like ISO 25010 in terms of stakeholder relevance?
(4 marks)
c. Why might a user be unaware of a system’s internal quality and still rate it poorly?
(3 marks)
a.
Operation: Runtime behavior (e.g., system responsiveness)
Revision: Ease of modification (e.g., maintainability of payroll system)
Transition: Ability to migrate (e.g., platform upgrade support)
b.
McCall focuses on technical maintainability and design (internal); ISO 25010 also includes user-facing traits like usability, security, etc.
c.
Poor external qualities like frequent crashes, delays, or incorrect outputs — even if internal code is technically “clean” — will lead to dissatisfaction.
a. The ISO 25010 model includes a characteristic called Functional Suitability.
Define it and list two sub-characteristics that fall under it.
(4 marks)
b. Choose any two ISO 25010 characteristics and for each, explain how they would be evaluated in a mobile banking app.
(6 marks)
c. Why is standardization (as in ISO 25010) important in global software development?
(2 marks)
a.
Functional Suitability: The degree to which software provides functions that meet stated and implied needs.
Functional completeness
Functional correctness
b.
Reliability: Does the app continue working during low internet?
Security: Is biometric login safe? Is user data encrypted?
c.
Ensures consistency, comparability, and confidence across developers, testers, and stakeholders globally.
Scenario:
You’re leading a team migrating a logistics software system to a new cloud environment. The stakeholders demand that this transition be smooth and transparent for users.
a. Based on the ISO 25010 model, which quality characteristic directly addresses this requirement? Explain.
(3 marks)
b. List and explain three sub-characteristics of Portability that would be evaluated.
(6 marks)
c. What challenge might arise if Portability is high but Compatibility is low?
(1 mark)
a.
Portability — It measures how well the system can move between platforms with minimal disruption.
b.
Adaptability: How easily software adjusts to new environments
Installability: Ease of installing it in the new system
Replaceability: Whether it can be swapped with alternatives easily
c.
It may install/migrate easily but won’t work well with other required systems (e.g., payment gateways).
a. Explain how the ISO 25010 characteristic “Security” goes beyond just encrypting user data. Give examples of at least two sub-characteristics.
(5 marks)
b. A system is highly usable and compatible but consistently produces incorrect outputs in edge cases.
Which quality characteristic is failing, and what could be the impact?
(3 marks)
c. Define “external quality” using your own words and give one metric you might use to measure it.
(2 marks)
a.
Confidentiality: Prevents unauthorized access (e.g., access control)
Integrity: Ensures data isn’t tampered with (e.g., hash checks)
b.
Functional Suitability — specifically, functional correctness is failing → could lead to legal or financial issues.
c.
External quality is how users perceive the product’s usefulness, reliability, and ease of use.
Metric: User satisfaction survey score
