Functional Testing – Basics Every Tester Should Know

Functional testing plays a crucial role in ensuring the quality and reliability of software applications. As a tester; it is important to have a solid understanding of the basics of functional testing is essential to effectively validate the functionality and behaviour of the software. In this blog, we will explore the fundamental concepts and principles of functional testing that every tester should know. By gaining a strong foundation in these basics, testers can enhance their testing skills and contribute to the delivery of high-quality software products.

What is Functional Testing?

Functional testing is a quality assurance process to confirm whether each application feature works as per the software requirements. This is a type of black-box testing. Black box testing where functionality is the primary focus, not software code. This form of testing verifies whether the software performs as the users expect.

Why is Functional Testing necessary?

Functional testing verifies the software functionality based on the Software Requirements. Without that, we can’t predict if the software working as per expected. 

What are the different types of Functional Testing?

1. Unit Testing: This testing makes a sure small part of the software work on its own. The unit testing first step of testing in the Software Development Life cycle. Also, this testing performs by the Developer.
2. Component testing: This testing is like unit testing. This performs to verify individual features of the software work as expected. This is also known as Module/Feature Testing. This Testing performs by Tester.
3. Smoke testing: Smoke Testing verifies that the critical functionalities of the software work fine after each build. This performs to check whether the software is stable or not. QAGENIC team doesn’t move forward if the smoke test fails, Build gets given back to the developer.
4. Sanity testing: This is a type of regression Testing performed after smoke testing. This performs to confirm code changes in software to provide a stable build of the software. This usually performs after a bug fix or small functionality changes.
5. Regression testing: This testing verifies the stability of software after any changes in the build. Also to check if changes don’t impact existing functionality or quality of software.
6. Integration testing: This testing performs to verify that the integration of software components works together. QAGENIC team confirms small components work together by performing integration testing.
7. System Testing: This testing performs after integration testing. In this testing, QA test the software as a complete product. Also, Confirm software meets the requirements once integrate into the software package.
8. UAT Testing: This is User Acceptance Testing. This testing ensures the product performs as per user needs. This is the final testing step. UAT is important functional testing that performs before moving the application to production.

Steps to Perform Functional Testing 

1. Identify the requirements: The first step before functional testing, understand the business requirements.  One of the important steps for successful testing.
2. Create a test Plan: A solid test plan is crucial for effective functional testing. QA must work on the test goals, so it is easy to schedule and arrange the test activities.  
3. Write Test Cases: After the test plan, the creation of functional test cases is a must. Test data, test input, and test output are the three key components that need in this situation.
4. Prepare Test Data: Testers should generate test data. Use test data as input to test certain functionality of the software. The information used to test applications refers to test input data.
5. Execute Test Cases: The test cases are then executed after test data creation. Use the test input data to execute test cases identified during the creation of test cases. 
6. Compare the actual and expected result: This is a major step. The actual and expected result comparison determines whether the tests pass or fail.
7. Log defects: The difference between the actual and expected outputs logs as a defect. The tester reports the defects to the development teams so that they can fix them as soon as possible.
8. Retest Bug: Retest performs to verify bug fixes. The software works as per requirements after the bug fix.

What are the different Functional Testing techniques?

1. Equivalence Test
2. Boundary Value Tests
3. Decision-based Tests
4. Error Guessing
5. End-user based Tests

In conclusion; functional testing forms the backbone of software quality assurance, allowing testers to validate the functionality and behaviour of applications. By grasping the basics of functional testing; testers can improve their testing approach, identify defects, and ensure that software meets the desired requirements. With a solid understanding of key concepts such as test cases, test data, and test coverage, testers can navigate the complexities of functional testing and contribute to the overall success of software projects. By continuously expanding their knowledge and honing their skills, testers can become invaluable assets in delivering reliable and user-friendly software applications.