Functional Testing – A Brief Introduction!

Functional testing is one of the processes in quality assurance services that assesses and validates the components or system against outlined specifications and expectations. In functional testing, the source code is not considered, thus, this is a type black-box testing. The primary focus of functional testing is to check the functionality of the application by putting in inputs and confirming the outputs against the functional requirement.

In other words, functional testing checks whether the software performance matches the user's expectations. It is also called specification-based testing as functional testing is completely based on program specifications.

Why is it needed?

Functional testing is crucial is assessing the functionality and quality of the software. QA companies use this technique to verify whether the software meets the end-user expectations and the outlined requirements and specifications. This testing is done to examine whether the system is fixed for the launch and is error-free.

Types of Functional Testing

The various types of functional tests are as follows:

Unit Testing

This is the first phase of testing in the software development lifecycle and the developers write scripts to assess whether the small units of the application are working as per the expectations.

Component Testing

This is similar to unit testing, but is performed by testers to examine every object of the application with or without isolation of other software objects.

Smoke Testing

This is build-verification testing and is performed after the release of each build. This test analyzes whether the test environment aspects are running properly, the stability of the build and whether it can be used for further testing or not.

Sanity Testing

This test is conducted after smoke testing, on receiving a software build with small changes if any. In other words, this test is used to examine whether the code works as expected after introducing the changes.

Integration Testing

This is one of the crucial software testing methods as it is used to test individual modules as a group to recognize the functionality after fusing different modules.

Regression Testing

Regression testing is used to ensure after any new changes are introduced in the code, to check they are not affecting the present features or functionality of the application.

System Testing

This form of functional testing is conducted after integration testing. This is a system testing process used for validating the fully integrated software system.

User Acceptance Testing

This is the last software testing stage where end-customers or clients step in the shoes of testers to assess whether the developed product is meeting the expectations or not. UAT is performed before moving the application for production.

Perform Functional Testing

There is a systematic procedure to perform functional testing as followed by the QA Companies. The steps are explained in details below:

Understand the Needs

Before starting the functional testing process, understanding the business requirements is a vital step. It is important to acclimatise with the needs of the business to make the further steps successful.

Design a Plan

Setting a goal test plan is vital for successful functional testing. Testers work on the goals of the test so that scheduling and organising test activities become easy.

Develop Test Cases

After the first two steps are followed, the next step is creation of functional test cases. While working on this test cases, test data, test input and test output is considered.

Create Input Data

Testers should create data and use it as an input to test the specific functionality of the application. This is called input data.

Execute Test Cases

In this step, the test input data is used for executing the tests.

Compare Outcomes with Expectation through Result Validation

In this step, the test results are compared with the expected outcomes to deduce the success of failure of the test.

Log Defects

While comparing the expected and the actual outputs, the differences identified are noted as log defects. The testers pass these log defects to the developers, so the same can be fixed.

Final Words

Functional testing is vital to ensure that the software functionalities match the end-user needs, and the outlined specifications.