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What are the different types of functional testing?

What are the different types of functional testing?

For successful software development, testing is a must-do activity. Before you release the product, you want most of the major bugs fixed and any errors erased, without testing, it isn’t possible. In this article, we are going to discuss functional testing. It checks whether an application or website does exactly what it is supposed to do. Functional testing can either be done by manual testers or it can be automated too.

Let us look at the different types of functional testing:

 #1 Acceptance Testing:

Acceptance Testing or User Acceptance Testing (UAT) shows how closely the application works according to the expectations of the user. It is usually performed only when all the bugs have been debugged. When UAT is conducted, the product should be market-ready as it will help you get a clear idea of how the application will work for the end users. It should be done by an actual end user of the product, as it will help them come up with better user-related deficiencies, if any.

#2 Unit Testing:

It is the testing of individual units with each unit being the smallest testable part of the software. Unit testing employs white box testing method and is performed with the help of a programming language. Before handing the application to the QA, the developers should do unit testing on the software. Since you use a modular approach for unit testing, your code becomes reusable.

#3 Integration Testing:

It is performed when different components and modules of the software are integrated together, and is usually performed after unit testing. It verifies the functionality, reliability and stability of the modules. It follows a bottom-up approach and a top-down approach.

In the former, we move from the bottom module to the top module where we integrate all the modules and then test them as a whole. In the top-down approach, the testing starts from the top module.

 #4 Beta Testing:

It is a standard practice to make the product available to a select few people to gauge their initial reactions, this is called Beta Testing. You can gain valuable insights by letting the end-users make use of the application in real world business situations. After the completion of the testing by internal teams, the product is sent for beta testing.

There are two types of beta testing:

Closed beta testing- At this juncture, the access to the application is only to a few people who have been chosen based on certain characteristics.

Open beta testing- It means anyone can use the software in the unreleased format and take advantage of it. It helps the business to obtain comprehensive feedback from a large group of testers.

#5 Smoke Testing:

The purpose of this software testing process is to determine whether the software which has been deployed is stable or not. It gives confirmation to the QA team to proceed with further testing. Smoke testing is also called confidence testing. To put it in simple terms, it checks if the important features are working and to see if the product built so far is flawed, thereby rendering further testing a waste of effort and time.

#6 Regression Testing:

In this, the existing software applications are tested to make sure that the recent changes in it haven't broken or affected any existing functionality. The objective of regression testing is to see if new bugs may have been introduced during a new release and also to ensure that the bugs that have already been fixed do not pose a problem anymore.

The need for regression testing arises when there is a requirement to change the code and when we need to ascertain whether the code that has been modified is affecting other parts of the software application.

Example of a functional test case:

Let’s take the case of an online survey tool where the customer has to use their login credentials that includes a username and password. Below the login fields, you can find the Sign In and Cancel buttons.

When a user inputs the correct details, they get directed to the survey tool from where they can create surveys. If they do not want to proceed, they can click on the Cancel button.

Here are the specifications. The username should have a minimum of 8 characters, and a maximum of 16 characters. Numbers and special characters are allowed. The password field should have a minimum of 8 characters and can use special characters.

In this scenario, let’s use the boundary value tests, a type of functional testing technique, to check how the system behaves when there are data limits. It checks how the system will behave when there are less than 8 characters inputted under username since it requires more than that. It checks for other scenarios as well where there are data limits.

 Functional test automation:

With the help of automation, you can reduce time and effort in executing functional tests. There will also be a reduction in human errors, thereby preventing bugs from recurring after the testing phase. If there is an increase in automation, the QAs should also have to develop test cases for each test. Therefore, ensuring that you design the right test case becomes imperative, and you need to identify the right automation tool for this purpose.

How to pick the right automation tool?

Here are a few pointers that you need to keep in mind while choosing the right automation tool

  1. It has to work seamlessly across different environments.
  2. It has to provide all the features that you are looking for in your team’s testing requirements.
  3. Your QA team should find the tool easy to use and navigate.
  4. If there are changes to the UI, the automation tool should support the reusability of the test cases.


Like we have mentioned above, there are a lot of functional testing options available and each of them are for different purposes. If you get your testing right, you will be able to deliver a product that is close to what is expected of it, and that’s the whole point. When you are planning a test project, ensure that you have considered the requirements, chosen the right mix of functional testing tools, and possess the technical know-how to conduct it successfully.

Zuci’s software experts will be more than happy to indulge in functional testing for your website or application. We have been helping organizations with our manual and automation testing expertise during every phase of the software development cycle. Reach out to see how we can be of help to you.


Keerthi Veerappan

An INFJ personality wielding brevity in speech and writing. Marketer @ Zucisystems.