Functional and Non-Functional Requirements

Question 1

What does a functional requirement do?

Answer 1

It specifies the behavior of a system

Question 2

What does a non-functional requirement do?

Answer 2

It specifies the qualities that the system should have

Question 3

List 9 examples of non-functional requirements

Answer 3

Look-and-feel,
Security,
Usability,
Performance,
Operational,
Maintainability,
Portability,
Cultural and Political,
Legal

Question 4

How are requirements prioritized?

Answer 4

MoSCoW - Must have, should have, could have, won’t have

Question 5

How should requirements be expressed (keyword to include)?

Answer 5

Shall (E.g. “The system shall”)

Question 6

Why do we need to be careful when we are expressing requirements in a natural language like English?

Answer 6

Because of ambiguity in requirements. Homonyms can have many meanings or words like it can be confusing.

Question 7

What is one desirable property of a set of requirements for a system?

Answer 7

Necessary,
Traceable,
Non-ambiguous,
Feasible,
Complete,
Consistent,
Verifiable

Question 8

What is the difference between FR’s and NFR’s?

Answer 8

FR’s are what things will do and NFR’s constrain the way things are done

Question 9

What is a fit criterion?

Answer 9

A precise and testable statement of a requirement to see if it is met

Question 10

Give an example of a fit criterion

Answer 10

90% of customers who use the machine at least weekly shall spend no more than 20 seconds in making a withdrawal