Functional vs non-functional requirements in Software Engineering - Quick Revision & Key Differences

Recall & Review

beginner

What are functional requirements in software engineering?

Functional requirements describe what a system should do. They specify the tasks, functions, or behaviors the software must perform to meet user needs.

beginner

What are non-functional requirements?

Non-functional requirements define how a system performs its functions. They include qualities like speed, security, usability, and reliability.

beginner

Give an example of a functional requirement.

An example is: 'The system must allow users to log in using a username and password.' This describes a specific action the system must perform.

beginner

Give an example of a non-functional requirement.

An example is: 'The system should load the homepage within 2 seconds.' This describes a quality or performance measure, not a specific function.

intermediate

Why are non-functional requirements important?

They ensure the system is usable, reliable, and efficient. Without them, a system might work but be slow, insecure, or hard to use.

Which of the following is a functional requirement?

A The system must send an email notification when a user registers.

B The system should be available 99.9% of the time.

C The system must load pages within 3 seconds.

D The system should have a user-friendly interface.

Functional requirements describe specific actions or behaviors, like sending an email notification.

Non-functional requirements usually describe:

A What the system does.

B The programming language used.

C How the system performs.

D The number of users.

Non-functional requirements focus on qualities like performance, security, and usability.

Which is an example of a non-functional requirement?

A The system encrypts user data.

B Users can reset their password.

C The system must allow file uploads.

D Users can create profiles.

Encrypting data is a security quality, which is a non-functional requirement.

Functional requirements are important because they:

A Improve user satisfaction.

B Define system features and behaviors.

C Make the system secure.

D Ensure the system is fast.

Functional requirements specify what the system must do.

Which statement is true about non-functional requirements?

A They are the same as functional requirements.

B They are optional for software projects.

C They describe system functions.

D They include performance and reliability.

Non-functional requirements include qualities like performance and reliability.

Explain the difference between functional and non-functional requirements with examples.

Think about what the system does versus how well it does it.

Why are both functional and non-functional requirements important in software development?

Consider what happens if one type is missing.