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Functional and Non-functional Requirements

by Anup Maurya
4 minutes read

Requirement analysis is very critical process that enables the success of a system or software project to be assessed. Requirement are generally split into two types are Functional and Non-functional requirements.

Functional and Non-functional Requirements
Functional and Non-functional Requirements

Functional Requirement

These are the requirement that the end user specifically demands as basic facilities that the system should offer. All these functionalities need to be necessarily incorporated into system as a part of the contract. These are represented or stated in the form of input to be given to the system, the operation performed and the output expected. They are basically the requirement stated by the user which one can see directly in the final product, unlike the non-functional requirement.


  • Authentication of user whenever he/she logs into the system.
  • System shutdown in case of a cyber attack
  • A verification email is sent to user whenever.
  • A verification email is sent to user whenever he/she registers for the first time on some software system.

Non-functional Requirement

These are basically the quality constraints that the system must satisfy according to the project contract. The priority or extent to which these factors are implemented varies from one project to other. They are also called non-behavioral requirements.

They basically deal with issues like

  • Portability
  • Security
  • Maintainability
  • Reliability
  • Scalability
  • Performance
  • Reusability
  • Flexibility


  • Emails should be sent with a latency of no greater than 12 hours from such an activity.
  • The processing of each request should be done within 10 seconds
  • The site should load in 3 seconds when the number of simultaneous are > 10000.

What is functional and non-functional requirements in QA?

Functional requirements are measured in simple yes/no terms as either present or absent in the completed system. Nonfunctional requirements are typically measured on some scale or interval. Listening to customer feedback is essential for updating nonfunctional requirements.

Is login a functional requirement?

A login form is a form with text input sections for our user. So, it’s a functional requirement too. Accessibility is talking about how accessible something is. So like usability, it is a quality, the quality of being accessible, and that makes it a non-functional requirement.

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1 comment

ankit November 30, 2023 - 4:52 pm

thank for such a wonderful and simple , easy to understand post


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