U-TOR sees a lot of confusion about the difference between functional testing and non-functional testing and manual vs automated software testing. All of these terms are important for making sure that the software quality is high.

The functional testing process involves a series of steps including creating a test plan, executing test cases, and analyzing the results to ensure the software meets its functional requirements.

A common question among developers is whether they should perform Functional or Manual Testing. While there is no one correct answer, this article helps you understand the difference between these two kinds of testing and what each can offer.

This article will explain the difference between functional testing and non-functional testing, as well as manual vs. automated testing.

What Does Functional Software Testing Mean?

Functional testing is a type of testing that helps the testers make sure that the software system meets the functional requirements or specifications.

In this type of testing, we check all of the software’s functions, such as all of the web page links and form inputs. We also make sure that a given input leads to the expected output, and we compare the results to the requirements.

Various functional testing techniques, such as equivalence testing, positive testing, and negative testing, are used to validate the behavior of the software.

Functional testing checks the user interface, application programming interfaces (APIs), database, security, Client/Server communication, and other parts of an application to ensure their functionality. It can be done by hand or with tools that automatically perform the testing.

Functional testing also looks at how well the application works from the end user’s point of view. We need to compare how the application actually works to how it should work, and any difference should be reported as a bug. A functional testing example could be testing a calculator app to ensure that all arithmetic operations produce the correct results.

Test data is crucial in functional testing, as it helps create test cases and manage inputs, configurations, and preconditions.

The main goal of this type of testing is to ensure that the application functions as expected, so if you are a software developer, it will be useful to integrate functional testing into your software development process.

The focus of functional tests

Functional testing focuses mostly on the following things:

• Functional test: Making sure that an app’s main features work as expected.
• The usability functional test is the test of how easy it is for a user to move around in an app without getting stuck.
• Accessibility: Testing how easy it is for users to use the app.
• Handling errors: testing for error conditions and making sure that the right error messages are shown.

Functional testing tools

Here is a list of some of the most popular tools that help automate the functional testing process:

• Selenium is a well-known open-source tool for functional testing.
• QTP is an easy-to-use functional test tool made by HP.
• JUnit is used mostly for Unit Testing and System Testing of Java applications.
• SoapUI is an open-source tool for functional testing that is mostly used for testing Web services. It works with several protocols, like HTTP, SOAP, and JDBC.
• Watir is a tool for making sure that web apps work properly. It lets you run tests in your web browser and uses the scripting language ruby. These functional testing tools help ensure that the software functions as intended and meets the specified requirements.

Functional Testing Methods

Here are the most common functional testing techniques:

Unit testing

Unit testing tests each unit or component of the software to see if it works in isolation. It means testing individual units, module functions, methods or classes when doing functional testing. Developers do this type of testing during the coding process.

Component testing

Component testing involves testing one functionality in isolation, often with sample data. This type of testing is good for finding and fixing issues with specific components before they get integrated into the larger software system.

For example, test data for component testing can be used to test the functionality of a login form on a website before it’s connected to the database and other components.

Integration testing

Integration testing tests how different software components interact with each other and if they work together as expected. It helps to find errors or issues that will arise when different units or modules of the software are integrated.

System testing

System testing in functional tests verifies if the entire system and all its components (units or modules) meet the requirements and work as expected. This type of functional testing checks for compatibility, scalability, and reliability of the system as a whole.

Smoke testing

Smoke testing is an initial test to see if the software’s basic functions work as expected. It’s a quick and simple test to make sure the system is stable enough for further testing. Smoke testing is done before any other type of testing, such as functional or integration testing. It helps to catch major issues early on in the development process.

For example, smoke testing may involve checking if the application can launch, if the basic navigation works, and if critical features are working. If there are major failures during smoke testing, it means there’s something serious with the code or functionality of the software.

Regression testing

Regression testing is done after code changes have been made to the software to ensure that the changes didn’t introduce new bugs or break some existing functionality. It involves retesting previously tested functionality and verifying if they still work as expected. Depending on the complexity of the software, this can be done manually or using automated tools.

Sanity testing

Sanity testing is quick and shallow functional tests to verify if the software’s major functionality works as expected. It’s a subset of regression testing that ensures recent changes or modifications to the software doesn’t break critical features. Sanity testing helps to find major issues or defects early in development.

Black-box testing

Black-box testing is a type of software testing where the tester doesn’t have access to the internal structure or code of the software. It involves functional testing of the software from an end-user’s perspective. Testers design test cases for black-box testing using various techniques such as equivalence partitioning, boundary value analysis and error guessing.

White-box testing

White-box testing focuses on functional testing of the software’s internal structure and code. Testers with access to the source code can analyze the code and create test cases based on it. This functional testing technique helps to find hidden errors, logical flaws, and missing functionality that may not be visible during black-box testing.

User acceptance testing (UAT)

User acceptance testing is functional testing done by end-users to validate if the software meets their requirements and expectations. It’s the last testing phase before the software is released to production. UAT ensures the software meets the needs of its intended users and works as expected in their environment.

End-to-end testing

End-to-end testing is a type of functional testing where all system components are tested together to ensure they work as expected from start to finish. This type of testing is important to find and fix potential issues when different components are integrated.

Equivalence testing

Equivalence testing is a type of software testing where different inputs produce the same output. It determines if the system behaves the same across various input values. This ensures the software works correctly in different scenarios and gives accurate results.

Additional functional testing techniques

In addition to these commonly used functional testing methods, there are also other types, such as acceptance testing, exploratory testing, and user interface (UI) testing.

• Acceptance testing involves checking if the software meets the specified requirements expected by software users.
• User interface testing is the process where the user interface of the software is tested for its functionality, usability and consistency.
• Exploratory testing is a method in which testers explore the software without any predefined test cases, allowing them to discover issues or bugs that may not have been identified through other testing methods.

Each of these functional testing techniques plays an important role in ensuring that web apps work properly. They help identify any bugs or errors in the code, ensuring that all functionalities meet the required standards.

Functional Testing Approach

The first step in the software testing process is often unit testing. This involves testing individual units or components of code to ensure they are functioning correctly. Unit tests can be automated or done manually by developers.

Once unit testing has been completed, integration testing comes into play. This involves testing the interaction between different units or components to ensure they work together seamlessly.

After integration testing, system testing is conducted. This involves testing the entire web application or software as a whole, making sure all features and functionalities are working properly. System testing can also include checking for any potential bottlenecks or issues with speed and responsiveness.

Another important aspect of functional testing is user acceptance testing (UAT). This involves having actual users test the app and provide feedback on its usability and overall experience. UAT helps identify any user experience issues that may have been missed during development.

Regression testing is also crucial in ensuring that new updates or changes to the app do not cause any unexpected issues or conflicts with existing functionalities.

What Does Non-Functional Testing Mean?

Non-functional testing or quality assurance (QA) testing is all about testing the app as a whole. It doesn’t involve the app’s features and functionalities but how it behaves.

Here are some non-functional tests:

Security testing

One aspect of non-functional tests is security testing, which ensures that the app has proper measures in place to protect user data and prevent cyber attacks. This includes checking for vulnerabilities like weak passwords or insufficient encryption methods.

Compatibility testing

Another part of non-functional tests is compatibility testing. This is about testing the app on different devices, operating systems, and web browsers. As technology keeps evolving, apps must be compatible with multiple platforms to reach a wider audience.

Performance testing

This software testing aproach is also part of non-functional testing. This is about testing the app’s speed, scalability and reliability under different conditions like high traffic volume or low network connectivity. It ensures the app can handle many users at the same time without crashing or experiencing significant delay.

Usability testing

Usability testing or user experience (UX) testing is another part of a non-functional test. This type of testing is about how user-friendly and intuitive the app is for its target audience. Usability testing considers factors like navigation, layout, and overall design to ensure a good user experience.

Load testing

This is a type of non-functional test that evaluates how well a system can handle a large number of users, transactions, or data volumes. It helps identify performance bottlenecks and ensures that the software can handle heavy usage without crashing or experiencing significant slowdowns.

Load testing also helps determine if additional resources or infrastructure are needed to support the application during peak usage periods.

Stress testing

Stress testing is a non-functional testing where the software is tested under heavy load to check its stability and performance limits. The goal of stress testing is to find out the weaknesses or bottlenecks of the system and how it handles high traffic or activity. This type of testing ensures the software can handle sudden surge of usage without crashing or slowing down significantly.

Stress testing

Stress testing is a non-functional test that simulates extreme scenarios to know the app’s limits and weaknesses. This helps to identify issues before they happen in real life.

In short, a non-functional test is all about the app working and having a good user experience.

Manual Testing Testing vs Automated Functional and Non-Functional Tests

Does non-functional and functional testing mean the same thing as manual tests?

No, they are not the same as testing that is manual.

It is a type of testing that helps testers ensure that an application meets the requirements for how it works. These tests can be run in two different ways:

• Manual testing (done by humans)
• Automated tests (done by machines)

Both manual testing and automatic testing are used to run functional and non-functional tests.

To perform functional testing effectively, it is crucial to have a structured approach that includes both manual and automated tests.

There are many ways to check how well the software works in web functional testing, such as unit testing, integration testing, end-to-end testing, regression testing, and more (as we detailed previously in this post). Most of the time, performance testing, security testing, usability testing, and compatibility testing are all part of non-functional tests. We can test by hand or with the help of tools that do the work for us.

Manual testing

Manual testing is a type of testing that can be used for both functional and non-functional testing. Functional testing and manual testing are not the same, as I’ve already said. In manual testing, we test the software by hand, meaning that we don’t use any tools that help with automation.

A person does manual testing by hand to look for bugs or strange things in an application. Testers, in this case, follow a written test plan explaining the set of scenarios, test cases, and steps they need to take to run tests and ensure the results match what was expected.

You have to test the app as if you were the end user during manual testing. You have to put yourself in the customer’s shoes and make a list of all the problems, UI/UX flaws, design improvements, and ways we can make the end-experience users better.

Automated testing

On the other hand, automated functional testing and non-functional testing are done by using tools and scripts to execute tests. This can save a lot of time and effort compared to manually doing the same work, such as executing functional tests, as the same tests can be run multiple times with consistent results.

Automated testing tools also allow for more comprehensive and in-depth testing, as they can handle larger datasets and perform tasks at a faster pace than human testers.

However, it is important to note that automated testing still requires human oversight and management, as bugs or errors in the test scripts themselves can lead to inaccurate results. Therefore, a combination of both manual and automated testing is often used for thorough software testing regardless if they are functional test cases or non-functional test cases.

Software testing depends heavily on manual testing. Before automating a project, it needs to be tested by hand.