Non-Functional Testing Complete Tutorial

Learn everything about non-functional testing, its advantages, disadvantages, tools and why is non-functional testing important in this guide.

Non-functional testing is a crucial aspect of software testing that focuses on testing the performance, reliability, usability and other non-functional aspects of a software system.

Unlike functional testing, which tests the software’s functions and features, non-functional testing evaluates the software’s overall performance and user experience.

Non-functional testing is becoming increasingly critical in today’s digital age, where software systems are expected to meet high standards of performance and user experience.

In this article, we will explore what non-functional testing is, its significance, the various types of non-functional testing, and some best practices for conducting effective non-functional testing.

Non-Functional Testing Video Tutorial.

Watch the video tutorial on Non-Functional Testing on ARC Tutorials YouTube Channel.

What is Non-Functional Testing?

Non-functional testing is a method of software testing that focuses on the non-functional aspects of an application or system. 

In other words, non-functional testing is concerned with verifying that the application or system is able to operate correctly in its intended environment and that it meets the non-functional requirements of the project. 

Non-functional testing can be performed at various stages of the software development process, and it typically involves the creation of test cases that are based on the non-functional requirements of the application.

Non-functional testing can help to identify defects, errors, or other issues that may affect the performance, security, or other non-functional aspects of the application, and can help to ensure that the application is working correctly and meeting its intended requirements.

Types of Non-Functional Testing

There are several types of non-functional testing that can be performed on an application or system, including the following:

1. Performance testing. Performance testing is a type of non-functional testing that focuses on the performance of the application or system. 
2. Load testing. Load testing is a type of performance testing that focuses on the ability of the application or system to handle a large number of concurrent users or transactions. 
3. Stress testing. Stress testing is a type of performance testing that focuses on the ability of the application or system to handle extreme levels of workload or usage. 
4. Security testing. Security testing is a type of non-functional testing that focuses on the security of the application or system. 
5. Usability testing. Usability testing is a type of non-functional testing that focuses on the usability of the application or system. 

Non-Functional Testing: Advantages

There are several advantages to using non-functional testing, including the following:

1. It can identify issues that may not be apparent from the user’s perspective. Because non-functional testing focuses on the non-functional aspects of an application or system, it can identify issues that may not be apparent from the user’s perspective. For example, it can identify performance bottlenecks, security vulnerabilities, or other issues that may affect the overall quality of the application.
   
2. It can provide insight into the overall performance and behavior of the system. Because non-functional testing focuses on the non-functional aspects of the system, it can provide valuable insight into how the system performs and behaves in its intended environment.
    
3. It can be performed early in the development process. Because non-functional testing does not require any knowledge of the internal workings of the system, it can be performed as soon as the application’s non-functional requirements have been defined. 
4. It can be automated. Because non-functional testing is focused on the overall performance and behavior of the system, it can be automated using tools that can perform the tests without any human intervention. This can save time and resources, and can also ensure that the tests are performed consistently and accurately.
5. It can improve the overall quality of the software. Non-functional testing can help to identify defects and issues that may affect the performance, security, or other non-functional aspects of the application, and can provide valuable feedback on how to improve the quality of the software. This can lead to a better user experience, and can also save time and resources in the long run.

Non Functional Testing: Tools

There are many non-functional testing tools available in the market that can help testers automate and streamline non-functional testing processes. Here are some popular non-functional testing tools:

1. LoadRunner: LoadRunner is a popular load testing tool that simulates user loads on a software system and measures its response time, scalability, and reliability.
2. JMeter: JMeter is an open-source tool used for load testing, performance testing, and stress testing of web applications. It is widely used for testing web applications and services.
3. AppDynamics: AppDynamics is an application performance monitoring tool that helps testers and developers monitor and optimize the performance of web and mobile applications.
4. Selenium: Selenium is an open-source tool used for automating functional and non-functional testing of web applications. It can be used for performance testing, load testing, and stress testing of web applications.
5. Apache JMeter: Apache JMeter is an open-source tool used for load testing and performance testing of web applications. It simulates user loads and measures the software system’s response time, scalability, and reliability.
6. Gatling: Gatling is an open-source tool used for load testing, performance testing, and stress testing of web applications. It is widely used for testing web applications and services.
7. BlazeMeter: BlazeMeter is a cloud-based load testing tool that allows testers to simulate user loads on web applications and measure the software system’s response time, scalability, and reliability.

Non Functional Testing: Disadvantages

There are also some disadvantages to consider, including the following:

1. It can be time-consuming and resource-intensive. Non-functional testing requires the creation of test cases based on the non-functional requirements of the application, which can be time-consuming and require a significant investment of resources.
   
2. It may not provide adequate coverage. Because non-functional testing is based on the non-functional requirements of the application, it may not provide adequate coverage of all the possible scenarios in which the application may be used. This can result in missed defects or functional issues that only become apparent once the application is in use.
   
3. It is not always effective. Because non-functional testing is based on the non-functional requirements of the application, it may not be effective in identifying defects that arise from a lack of understanding or incorrect interpretation of those requirements. This can result in the creation of test cases that do not adequately reflect the intended behavior of the application.
4. It is not suitable for all types of testing. Non-functional testing is most effective for tests that are based on the non-functional requirements of the application, such as performance testing or security testing. However, it may not be suitable for tests that require a high degree of flexibility or creativity, such as exploratory testing or usability testing.
5. It can lead to over-reliance on the test results. Because non-functional testing is focused on the overall performance and behavior of the system, it can be tempting to rely too heavily on the test results. However, it is important to remember that non-functional testing is only one part of the overall testing process, and it should be used in combination with other testing methods to ensure the overall quality of the software.