What’s the Difference Between Functional and Non-Functional Testing?

Difference between Functional and Non-Functional testing?

What’s the Difference Between Functional and Non-Functional Testing?

Functional and non-functional testing service is commonly included in well-designed quality assurance strategies and programs. As a result, testing and quality assurance teams must be aware of functional and non-functional testing differences. While both are critical components of the application review process, they serve quite different functions.


Let’s Begin By Defining Functional testing And Non-functional testing.



What is Functional Testing?

what is Functional-Testing?

Functional testing confirms that each software program function follows the required definition. This testing mostly consists of black-box testing and is unconcerned with the application’s source code. Every system function is validated by providing suitable input, checking the output, and comparing the actual results to the predicted results.


What is Non-Functional Testing?

what is Non-Functional-Testing?

Non-functional testing is designed to assess a system’s readiness using non-functional factors never addressed by functional testing. Checking how many individuals can simultaneously login into software is an example of a non-functional test. Non-functional tests are just as important as functional testing and impact customer satisfaction. 

The major distinction between functional and non-functional testing

We need to comprehend the difference between functional and non-functional requirements before we can understand the difference between functional and non-functional testing:

Functional Testing Vs Non-Functional Testing: What's the Difference?

  • Non-functional testing verifies non-functional elements such as performance, usability, and dependability, while functional testing verifies each function/feature of the product.

  • Non-functional testing is difficult to execute manually, whereas functional testing is done manually.

  • The purpose of functional testing is to validate software actions, whereas non-functional testing is to validate software performance.

  • A functional testing example would verify login functioning, but a non-functional testing example would be to verify that the dashboard should load in less than two seconds.

  • Non-Functional defines how the thing operates, whereas Functional tells what it does.

  • Before non-functional testing, functional testing is carried out.


Strategies For Functional Testing


A combination of human and automated testing is the best way to achieve functional test coverage. Black-box testing methods are the most prevalent functional testing methodologies. The tester does not need to inspect the internal source code and validates functionality by testing various input combinations.


Here are a few examples of common Functional testing methods:



Functional Testing - javatpoint

  • Installation testing – whether for a desktop or mobile app, make sure it’s installed correctly.

  • Testing the boundaries of numerical inputs are known as boundary value analysis.

  • Unit testing is software testing done at the smallest level possible—not how the system works, but whether each unit works properly.

  • API testing verifies that internal and external APIs, including data transfer and permission, are working effectively.

  • Regression testing is a set of tests used to ensure that new software modifications have no negative impact on current functionality (the most common automation technique).


Strategies for Non-Functional Testing



Because you’re testing what the consumer wants for an overall quality experience rather than X input leads to Y result, non-functional testing might often take more imagination and technical expertise.

Here are a few examples of common Non-functional testing methods:

Functional Vs Non-Functional Testing: Expert Guide - UTOR

  • Load testing is the process of assessing the behavior of a system in a simulated environment under predicted conditions (various numbers of users)

  • Stress testing evaluates performance when resources are scarce, such as when a server is down or there isn’t enough capacity on a device’s hard drive.

  • Scalability testing determines whether or not a system can scale with additional usage and, if so, how much performance is impacted.

  • Security testing determines how vulnerable a system is to attack and safeguard data.

  • Volume testing evaluates performance with a large amount of data, not necessarily involving a large number of users, but rather a single person executing a high-volume job, such as multiple-file uploading.

Functional V/s Non-functional Testing 

Parameters Functional Testing Non-Functional Testing
Execution It is carried out before non-functional testing. This is done when the functional testing is completed.
Requirement Functional requirements are simple to define. IT requires a lot of effort to define the requirements.
Usage Assists in the validation of the application’s behavior. Assists invalidating the application’s performance.
Objective The goal was to validate software actions. The goal is to ensure that the software performs as expected.
Requirements Functional testing is conducted using the functional specification. Performance requirements are used to carry out this type of testing.
Manual testing It is a simple way to carry out functional testing. It is extremely difficult to execute manually.
Functionality It refers to the product’s ability to do certain tasks. The term “functionality” refers to how a thing functions.