Use Cases - USP

Question 1

What are non-functional requirements (NFRs)?

Answer 1

System qualities describing how well a system performs its functions, e.g., usability, performance, and security.

Question 2

How are NFRs related to functional requirements?

Answer 2

NFRs describe the system’s design qualities, while functional requirements describe what the system does for users.

Question 3

How are NFRs modeled?

Answer 3

By attaching them as comments to relevant functional requirements.

Question 4

What is usability in software design?

Answer 4

Design focused on helping users complete tasks with minimal cognitive effort, improving effectiveness, efficiency, and satisfaction.

Question 5

What are the three parts of usability?

Answer 5

Effectiveness: Users find what they want; Efficiency: Minimal resources/effort; Satisfaction: Users enjoy the experience.

Question 6

What is performance in software?

Answer 6

A measure of latency and reliability, ensuring the system is fast enough to match or exceed users’ cognitive processing speeds.

Question 7

What are key considerations for performance?

Answer 7

Volume of data, processing at each end, bandwidth, bottlenecks, and interdependencies in hardware/software.

Question 8

What is the relationship between usability and performance?

Answer 8

Better performance increases usability, provided the system doesn’t slow down user tasks.

Question 9

What is security in software?

Answer 9

Protecting sensitive data, system integrity, and operation from theft, abuse, or attacks.

Question 10

What are examples of security threats?

Answer 10

Unauthorised access, exploitation, denial of service, trojans, eavesdropping, and spoofing.

Question 11

How can security be modeled?

Answer 11

Through abuse cases and threat analysis, complementing cybersecurity measures.

Question 12

What is the best security for a system?

Answer 12

A private, isolated network, though impractical for public use due to networking needs.

Question 13

What are historical approaches to security?

Answer 13

Zones of security, barriers, gateways, and lessons from physical defenses like castles.

Question 14

What are modern cybersecurity layers?

Answer 14

Firewalls, security zones, encryption, certification, and monitoring to defend against attacks.

Question 15

What is the role of a firewall?

Answer 15

Hardware/software acting as a barrier between internal and external networks to prevent invasions.

Question 16

What are examples of security zones?

Answer 16

Levels of access based on public accessibility and the value of secured assets.

Question 17

What is an abuse case?

Answer 17

A use case identifying actions of ‘bad actors’ to reduce their reward and increase their effort.

Question 18

What are the five principles of secure system design?

Answer 18

1. Establish context; 2. Make compromise difficult; 3. Make disruption difficult; 4. Detect compromise easily; 5. Reduce impact of compromise.

Question 19

How does cybersecurity balance access and vulnerabilities?

Answer 19

More networking increases access but also introduces vulnerabilities; security balances these concerns.

Question 20

What is an example of a real-world cyber attack?

Answer 20

A Russian attack on NHS provider Synnovis disrupted services, canceling 10,000+ appointments and postponing operations.