Ushima Chhabra

Major Types Of Software Testing

By Ushima Chhabra

Last updated cal_iconMarch 12, 2022

In this blog I’ll be explaining…

  1. The major types of software testing methods.
  2. And why should these testing should be performed.

There are wide number of software testing methods that are performed to ensure the quality and user experience of an application or software. And sometimes it’s get really hard to choose which software testing method best fits for an application or software. So, let’s discuss the major testing methods.

The software testing is mainly divided among two types:

  1. Functional Testing
  2. Non-functional Testing

What is functional testing?

Functional Testing is a process to verify that each function of the software application operates in conformance with the requirement specification. Functional testing is a quality assurance (QA) process that mainly involves Black Box Testing. It is mainly concerned about the results of processing and not about the source code of the application.

Definition: Functional Testing is a type of software testing whereby the system is tested against the functional requirements/specifications.

The features are tested by providing appropriate input and examining the outcome. The actual outcomes are then compared with expected outcomes. Functional testing ensures that the requirements are properly met by the application. The testing can be done either manually or using automation.

In functional testing, we verify each function/feature of the software. It is based on customer requirements. Each function should be operating according to the customer’s specifications and show off the best-desired execution. The functional testing requirement is to give a clear picture of the system’s behavior.

There are various types of functional testing and we will understand the widely practiced techniques and why these are required-

The functional testing types that we will discuss are-

  1. Integration testing
  2. Interface testing
  3. User interface testing
  4. Unit testing
  5. System testing
  6. Regression testing

Integration testing:

As the word “integration” itself suggests, integration testing is the testing of a subsystem which comprises two or more integrating components. It ensures that multiple components of systems work as expected when they are combined together to produce a result. It is performed once the individual components have been unit tested and are working as expected. It is carried out with the objective to find defects in the interfaces and the interactions between the integrated components.

Why integration testing should be performed ?

The objective of integration testing is to reduce the risk of finding defects in integrated components in the System testing phase. Integration defects can be complex to fix and they can take too much time as well. Finding them early in the cycle reduces the risk of making too many changes at the System testing phase. As each of the integrating components is already tested in the integration phase, the System testing can focus on end-to-end cycle and user-specific flows.

  • Reducing risk by testing integrating components as they become available.
  • To build reliance on the quality of the interfaces.
  • To find defects in the components, system, or in interfaces.
  • Prevents defects from escaping to higher test levels of testing i.e. System testing.

Interface testing:

Interface Testing is a type of testing process used to validate the interaction between the two systems or applications that are involved in the software application. In this testing, the interface of the application is verified for its behavior when other integrated applications are establishing connections or trying to transfer contents amongst one another.

So it is done to verify and test the communication between the two software or the components of the same software. It involves the testing interfaces like APIs and web services. It is one of the most important tests in order to ensure smooth and safe communication between the components in software. 

The connection which integrates and facilitates the communication between server, database, etc. is termed as an Interface. In simple terms, an interface is software consisting of a set of commands, messages, etc. An interface can be APIs, web services, etc. The communication between the different components of a software or an application or a website can affect the overall performance and hence the interface also needs to be tested and verified. It is performed only on the code and is almost automated.

Why interface testing should be performed ?

There are certain scenarios like an unauthorized user trying to steal or access the data, some server error while retrieving or manipulating data, etc. In order to ensure that such problems should not happen and the smooth flow of all the integrated components should work, it is performed.

  • In order to ensure the smooth functioning of the application for the end-user.
  • In order to check the security breach in an application while communication between the two or more interfaces.
  • To verify that the communication is capable enough to handle various situations like network failure, server restart, etc.
  • To verify error handling is done properly and the correct error message is displayed to the user for various situations.

User interface testing:

User interface testing or Graphical User Interface is the part of an application that is visible to users. An ideal GUI test may contain elements such as menus, buttons, text boxes, and images. UI testing includes two major checks: how the application handles user interaction and whether the visual components are displayed as needed.

We can think of UI as anything that an end-user will interact with when using a piece of software. Every action the user performs on the software is done on its user interface. This usually means testing the visual elements to verify that they are functioning according to requirements — in terms of functionality and performance. UI testing ensures that UI functions are bug-free.

Websites comprise web elements created with CSS, JavaScript, and numerous other programming languages. UI testing performs tests and assertions of these elements to validate their efficacy. It is focused on examining visual and structural parts of the software i.e. parts the user would be concerned with, rather than the internal logic of the software.

Why interface testing should be performed?

In software development, quality can be defined by delivering an application with the functionality and ease of use to meet a customer’s need and is as free of defects as possible. To improve quality, development teams seek to build it into their projects right from the start. It becomes very important to test each and every aspect of it.

  • As the website/apps deal with increasing numbers of competitors in their field, the standards for user experience should keep on rising.
  • UI testing is necessary to meet these standards by ensuring that every feature works as expected.
  • UI testing is also necessary to ascertain if the visual and auditory aspects of the website/apps are satisfying and capable of keeping the user interested.

Unit testing:

A unit is the smallest testable part of an application like a feature or a function. Unit Testing is a software testing method by which individual units of source code, sets of one or more program modules are tested to determine whether they are fit for use. These tests are basically written and executed by software developers to make sure that code meets its design and requirements and behaves as supposed.

Primarily, a unit test verifies different behavioral aspects of the system under test and can be broadly classified into state-based and interaction-based unit testing.

Why unit testing should be performed?

Unit testing effectively helps in validating the accuracy of a section of code by considering stubs, mock objects, drivers, and unit testing frameworks. It is practiced at the initial testing phase, and this testing technique assures to identify and fix the bugs at the early stage of SDLC leading to save the expenses by reducing the chance of being identified at later stage.

  • Segregates a section of code and validates its correctness.
  • Helps in identifying and fixing the bugs at the early stage of the SDLC process.
  • Assures to reduce the cost as bugs are resolved at the earliest stage.
  • Helps the developers to improve the design by allowing refactoring of the code.
  • Assures in simplifying the debugging process.

System testing:

System testing is a process of testing the entire system that is fully functional, in order to ensure the system is bound to all the requirements in the form of the functional specification or system specification documentation as provided by the client. In most cases, it is done next to the Integration testing, as this testing should be covering the end-to-end system’s functioning.

This type of testing requires a committed Test Plan and test documentation derived from the system specification document that should cover both software and hardware requirements. This type of testing does not require knowledge of internal design or structure or code. By this test, we detect errors. It ensures that all the system works as expected. We check System performance and functionality to get a quality product. System testing is nothing but testing the system as a whole. This testing checks complete end-to-end scenarios as per the customer’s point of view.

Why system testing should be performed?

It is very important to complete a full test cycle and system testing is the stage where it is done. It is performed in an environment that is similar to the production environment and hence stakeholders can get a good idea of the user’s reaction. 

System testing helps in minimizing after-deployment troubleshooting and support calls. This testing is very important and it plays a significant role in delivering a quality product to the customer.

  • In Software Development Life Cycle the system testing is performed as the first level of testing where the System is tested as a whole.
  • We check if the system meets functional requirements or not.
  • To test, validate and verify both the application architecture and business requirements.
  • The application is tested in an environment that particularly resembles the production environment where the application will be lastly deployed.


Regression testing:

In a software application, when new changes are made in the existing system or a new feature is added to the application, it is crucial to test the application modules that are impacted by this new requirement. This type of testing is known as Regression Testing. 

For regression testing, there is no need to design new test cases. Instead, a cluster of test cases is picked from the prior test execution, which is applicable for testing the affected application modules. Most of the time, this is carried out using an Automation Testing tool. 

Regression testing can also be understood as re-executing test cases that have been cleared in the past against the new version to ensure that the application’s functionalities are working as required. It is a series of tests performed whenever you add a new code.

Why regression testing should be performed?

It is required to be performed to detect any issue after a new deployment, or any issue has been fixed. There is defect fixing or bug fix, change in requirement, modification of code, and newly added features to the product or software. 

The regression testing has to be done for the last-minute deployments and changes done to software or application in production or any other environment.

  • Check the functioning of the core features of the product like new, edit, and view.
  • Verify test cases, which have logged the defects more frequently.
  • Covers types of cases like a boundary test case, integration test case, and complex test case.
  • The functionalities on which the changes are done or bugs have been fixed.
  • Verify all types of successful test cases and failed test cases.

So, we have covered the major types of functionality testing methods. Now let’s move to know about non-functional testing and it’s types:

What is non-functional testing?

Non-functional testing includes totally different types of system/application testing. It deals with non-functional software parameters, such as usability, security, reliability, scalability, and other features. It is about checking the program’s behavior and performance, but not its functions. Non-functional testing is performed to make sure the customers will have the best user experience when using the service. The app should be understandable, convenient, stable, and user-friendly.

Definition: Non Functional testing is a type of testing that emphasizes the behavior of the product and not the functionality.

Non-functional testing ensures the high maintainability and efficiency of the product. It optimizes the program’s installation and configuration and reduces the risks that are connected with the non-functional areas of the software. It is as important as functional testing.

There are various types of non-functional testing and we will understand the widely practiced techniques and why these are required-

The non-functional testing types that we will discuss are-

  1. Installation testing
  2. Reliability testing
  3. Performance testing
  4. Security testing

Installation testing:

Installation testing is performed to check if the software is correctly installed with all the inherent features and that the product is working as per requirements. Also known as implementation testing, it is done in the last phase of testing before the end-user has the first interaction with the product.

With the assistance of installation testing, the testers are able to validate the quality as well as the correctness of the installation process and ensure that the users receive the best user experience.

In cases when the installation is dependent on other components such as a database or a server, test cases should be written specifically to address this. Along with the positive test cases, negative scenarios such as insufficient memory, insufficient space, and an aborted installation should also be covered within installation testing.

It should be ensured that clear messages are given to the user in cases of failure and that the installation can be continued after increasing memory, space, or anything else which forced the install to abort.

Why installation testing should be performed?

The importance of installation testing is because it is the very first point of interaction between the user and application. And to provide the optimum user experience it becomes necessary to detect any defect or failure from the installation process.

  • Installation testing identifies and detects bugs and issues during software installation.
  • It helps to deliver an optimal user experience.
  • It helps to verify the ease of installation over the internet.
  • To verify that the instructions of installation are displayed correctly.

Reliability testing:

Reliability Testing is a software testing process that checks if the software can perform a failure-free operation for a specified time period in a particular environment. The purpose of this testing is to assure that the software or application is bug-free and reliable enough for its expected purpose.

The implementation of reliability testing makes sure that the software product is defect-free and reliable for its planned objective.

In general terms, Reliability signifies yielding the same; in other words, reliable means something is dependable, and both will provide the same outcome each time. And the same is true in the case of Reliability testing.

Why reliability testing should be performed?

Reliability testing is done to test the software performance under the given conditions. To test the working of software under a specific condition is the significant purpose of Reliability testing.

  • Determine the number of defects in a specific period.
  • Determine the perceptual structure of monotonous breakdown.
  • Find the nasty presence of the software.
  • Identify the leading cause of failure.


Performance testing:

Performance Testing is carried out to evaluate the performance of components of a particular system under a particular workload. During this testing, system components are monitored to verify the stability of the system under test.

It strives to build performance standards into the implementation, design, and architecture of a system. It is done to provide stakeholders with information about their application regarding speed, stability, and scalability. And it uncovers what needs to be improved before the product goes to end user. 

The software is likely to suffer from issues such as: running slow while several users use it simultaneously, inconsistencies across different operating systems and poor usability without performance testing With the help of performance testing we can determine whether the software meets speed, scalability and stability requirements under expected workloads.

Performance testing includes various types of testing methods, such as:

a.) Load testing: it checks the application’s ability to perform under justified user loads. The objective is to identify performance bottlenecks before the software application goes live.

b.) Stress testing: involves testing an application under extreme workloads to see how it handles high traffic or data processing. The objective is to identify the breaking point of an application.

c.) Endurance testing: it is done to make sure the application can handle the expected load over a long duration.

d.) Spike testing: it tests the application’s reaction to sudden large spikes in the load generated by users.

Why performance testing should be performed?

We need performance testing in order to establish the benchmark behavior of the system. It does not aim to find defects in the application rather this focuses on measuring characteristics, such as response times, throughput or the meantime. This can be done in different ways depending on the tool, such as different user profiles, different types of activity, timing delays and other parameters.

  • Eliminates performance congestion.
  • Uncovers what is needed to be improved before the product is set to go live.
  • Makes application rapid.
  • Makes software stable and reliable.

Security testing:

Security testing determines that the security mechanism of an information system protects data and maintains functionality as needed. It is done to check whether the application or the software is secured or not. It checks whether there is any information leakage in encrypting the application or using a vast range of software, hardware, and firewall, etc. 

It ensures that no one can hack the system and login to the application without any authorization. This testing is used to verify if the users with only proper authentication are allowed to access the application, while those that fail the authentication are restricted from using the application.

Why security testing should be performed?

Security is a very important aspect in software/application development. The main purpose of Security Testing is to identify the threats in the system and measure its potential vulnerabilities, so the threats can be tackled and the system does not stop functioning or can not be exploited. 

It helps in detecting all possible security risks in the application and helps developers to fix the problems. Also to gain the client’s trust and provide a secure application it becomes mandatory to perform the security testing.

  • Disturbance to your online system can lead to revenue impact.
  • Website downtime can lead to time loss and expenditures in recovering from damage.
  • It saves cost associated with securing web applications against future attacks.
  • Related legal implications and fees for having lax security measures in place.

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