Difference Between Functional Testing And Non-Functional Testing

Software organizations are striving not only for bug-free products, but also for products that perform well in this fast-paced world of technology development. Here, we will discuss the two main methods of automation testing quality and performance in this article: Functional testing and Non-Functional testing.

So, without any further wait, let’s get started.

Functional Testing: What is it?

As part of functional testing, a software or application under test is analyzed for its functionality. The software under test is also tested for its behavior. To test the application, a document called a software specification or Requirement Specification is used based on the client’s requirements.

The software is tested in a real environment to see whether it meets the expected results. Test data is sculpted based on it and test cases are prepared. In addition to being extremely effective in finding bugs, this technique is also called the Black Box Technique, which is mostly carried out manually.

Types Of Functional Testing

Let us now take a glance at this section where some of the types of functional testing are mentioned.

• To ensure important functionality is operational before undergoing more detailed testing, smoke testing is conducted prior to actual system testing. By doing so, you can save time and energy by installing the latest build once again and eliminate the need for further testing if important functionality is not working. This is a general approach to testing an application.
• To ensure that functionality is working correctly and that there are no additional issues caused by changes to the related components, sanity testing is a form of testing in which only a particular function or a defect that has been addressed is tested. A separate method of testing the program is used.
• A user acceptance test assesses the program’s ease of use, comfort, and acceptance by the user. In order to see if the program works in a real-world environment, the actual end users or clients are given a trial version to use in their office setup. It is also referred to as beta testing or end-user testing and takes place before the final launch.
• As a result of integration testing, two or more software functionalities or components are combined to form a single unit. This process tests the functionality of the combined system.
• During regression testing, the team checks to see if any of the bugs found during the initial testing of the software have been addressed, and if the adjustments made have put the software in working order.
• When software is localized into an application in another language as requested by the client, localization testing is performed.

Functional Testing: What are the Benefits?

For an enhanced understanding of the efficacy of functional testing, consider these benefits of this software quality assurance testing:

1. User Satisfaction

It is solely intended to ensure that the software performs satisfactorily for the end user or customers through functional testing. Using the application provides the easy way out for users. Software or applications with bugs and inappropriate features are not what users desire. 

2. No Defect Assurance

During this functional testing phase of software development, all subtle bugs and errors will be identified and eliminated in order to streamline the software’s functions. This way, you will get bug-free software. 

3. Enhanced Functionality

As a result of functional testing, application loopholes can also be easily detected. If the application’s code or attributes need to be improved, the developers will comply with the test results and take action accordingly. Consequently, the application’s functionality will eventually be improved. In addition, this test would allow us to know if the application is working as expected. 

4. Better Security

In addition to the functional testing attributes, security-related testing is also part of the testing process. It would eventually let us know if the application is secure for storing sensitive information. 

Non-functional Testing: What Is It?

Unlike functional testing, non-functional testing examines the application’s non-functional requirements. It determines whether the system’s behavior meets the requirements. It tests all aspects of the application that may not be covered by functional testing.

An evaluation of non-functional features of a software program is called non-functional testing. Non-functional testing is a method of assessing a system’s readiness based on nonfunctional criteria that functional testing never addresses. It is just as vital as functional testing.

Benefits Of Non-functional Testing

Suppose you develop an application and fully test it for functionality, but don’t test it for non-functional requirements. Now imagine a massive load is placed on it once it goes live.

As a result of non-functional testing, it would be very unclear if the application could handle massive traffic. The application may become slow or even crash in the worst case scenario. Imagine the embarrassment if this were the case! If the application is not secure, an unauthorized party would be able to easily crack the data entered by its users if it wasn’t tested for security.

Non-functional testing is just as imperative as functional testing. It ensures security and enhances the application’s reliability. It makes sure the application is robust enough to withstand extreme pressure. Non-functional testing determines and verifies the app’s compatibility with various devices, its ease of use, its endurance, and a host of other vital parameters.

Types of Non-functional Testing

In this section of the blog, we will have a look at some of the types of non-functional testing.

1. Performance Testing – Performace testing can be further sub-divided into these categories:

• Application load testing is the process of testing an application’s response time in a real-world scenario simulating a specific workload. A load test assesses the application’s ability to manage a load and perform correctly.
• A stress test is performed on an application to test its ability to handle additional workload while performing efficiently. Suppose a website is being tested to see how it performs when accessed at its peak. There is a possibility that the workload will exceed the specification. The website may stop functioning, slow down, or even crash under these circumstances. Using automation techniques, stress testing replicates a real-time workload environment and identifies errors.
• Volume testing evaluates an application’s capabilities to manage data in a volume by using real-time environments. The application is tested for correctness and dependability under severe conditions.
• A software endurance test assesses how long it can last using a predictable pattern of load flows that arise over time. It evaluates how long it can withstand consistent workloads over time. In order to provide a high-quality product, these testing methods are used to ensure that a product is bug-free and crashes-free in real-world conditions.

2. The purpose of usability testing is to assess how easy it is to use and how usable the User Interface is.

3. A program’s safety is determined by its ability to protect data from hostile attacks during transmission over a network. During this test, permissions, authentication, and user access will be tested according to the roles of admin, moderator, composer, and user.

The Primary Distinction Between Functional and Non-Functional Testing

The distinction between functional and nonfunctional testing can be better understood, by reading the following:

• Software functional testing validates features and functions, while non-functional testing verifies performance, usability, dependability, and other non-functional characteristics.
• It is possible to perform manual functional testing, but it is difficult to perform manual non-functional testing.
• The intent of non-functional testing is to understand what customers expect, while the intent of functional testing is to understand what the customer wants.
• Software functional testing validates features and functions, while non-functional testing verifies performance, usability, dependability, and other non-functional characteristics.
• It is possible to perform manual functional testing, but it is difficult to perform manual non-functional testing.
• The intent of non-functional testing is to understand what customers expect, while the intent of functional testing is to understand what the customer wants.
• Software activity testing is aimed at validating software activities; non-functional testing is aimed at validating software performance.
• Software activity testing is aimed at validating software activities; non-functional testing is aimed at validating software performance.
• An example of Functional Testing would be to ensure that the login capability is working, while an example of Non Functional Testing would be to ensure that the dashboard loads quickly.
• Functionality describes what the product can do, while non-functionality describes how it operates.
• In order to perform functional testing, non-functional testing must first be conducted.

We will now compare both functional and non-functional testing based on a few other parameters

1. Area of focus
2. Objective
3. Functionality
4. Execution
5. Ease of use

In order to get a healthier understanding of how these types of software testing differ, let’s take a closer look at these parameters

1. Area of focus: Functional testing looks at the requirements of the system, how it should behave under certain circumstances, and the processes involved, whereas Non-functional testing looks at the expectations of the user, such as how the system works, how it interacts with the user.
2. Objective: Functional testing focuses on evaluating and validating software actions like the login function, while non-functional testing focuses on evaluating and validating the software’s performance.
3. Functionality: It is important to designate what the system should do in functional testing, and how it should function in non-functional testing. In other words, functional testing provides answers to every question about the system’s functions, while non-functional testing answers every question about the system’s hows.
4. Execution: It is important to carry out functional testing before non-functional testing. This is because Functional testing describes all processes and is executed first, whereas Non-functional testing executes only after Functional testing has been executed because you can only proceed and customize the system if the system is defined.
5. Ease of use: Functional testing is easy to perform, while black box testing is difficult because the user cannot see the internal implementation. As opposed to functional testing, which can be carried out easily using white box testing where the internal structure and implementation process are known to the user, and transparent operations are being carried out.

This is what differentiates Functional Testing from Non-functional Testing.

Conclusion

As part of the software development process, functional testing has always been an essential component. Without it, the software cannot perform correctly once it is launched. Functional testing is the best way to ensure the application is error-free before it is launched. 

In software testing, non-functional testing is a critical component. Without it, a product or application would not be considered complete, since it ensures the behavior and needs are met.

It is important to strategize and plan for non-functional testing. In any case, the ultimate goal is to cover all non-functional aspects of the concerned software comprehensively, whether it is included in the test plan or created as a separate strategy.

Testing can also be done manually, but testers prefer automated tools for speed. There are multiple tools available for functional testing as well as non-functional. Choosing amongst them is a bit difficult. LambdaTest is a cloud-based platform for automating Selenium and Cypress testing across multiple platforms for your web application. Additionally, it offers a number of features, such as video recording, screenshots, and interactive testing.