Software Testing 101: Types of Software Testing

Every engineer knows the importance of using diverse types of testing in software development. Here, we’ll mention some of the most important testing strategies you should know.

The Importance of Quality Assurance, Control, and Testing

We can say that QA focuses on providing continuous and consistent improvement of software products so that Quality Control (QC) can monitor whether the product behaves as expected. QA focuses on preventing any omissions that could affect the software’s functionality.

A graphic illustrates how Quality Assurance, Quality Control, and Testing work in tandem to resolve errors in software development.
QA, QC, and testing all go hand-in-hand to create a superior software product.

Types of Testing Strategies in Software Engineering

What is Software Testing?

Software testing is a process used to evaluate the functionality of a software application. It is performed with the intent of producing a quality product that meets specified requirements and is defect free.

Test Strategies

A good test strategy is a key factor that often determines a product’s quality. Testers and test team leaders decide on the approach according to product requirements and potential problems that a certain software type might have.

  • Analytical
  • Model-based
  • Methodical
  • Process
  • Dynamic
  • Consultative or Directive
  • Regression-averse

Choosing the Right Strategy

Because there are many areas to consider, it is not always easy to decide on the best testing approach. A QA team must consider the risks involved in the process, as it is not the same to develop an update for a well-established app versus build a new product.

Distinct Types of Software Testing

Mistakes are a common thing for every software engineer. However, some errors might come with a high cost. And with specific types of software testing, they could be eradicated. Since every software product should meet particular requirements, all its functions and features should deliver.

  • Testing by Aims
  • Testing by Execution Method
  • Testing-by-Testing Level

Types of Testing by Aims

Functional Testing

Every development project is unique due to its prioritization and testing activities. If you want to deliver quality software in a timely manner, QA teams ought to combine various approaches and testing types.

  1. Outlining the functions that software has to perform
  2. Data input
  3. Definition of the expected outputs
  4. Execution of the test
  5. Comparison of expected and received outputs

Confirmation Testing

When a QA team spots a bug and reports it, developers need to fix it so the software will get an updated version. Then, it’s time to re-execute the test case that failed. That way, the QA team can confirm that everything works well. Confirmation testing should be performed on all testing levels since it is one of the best ways to validate software functionality. It is important to ensure such testing is executed in exactly the same way as it was the first time, using the same inputs, data, and environment to not introduce any new variables.

Regression Testing

Another useful functional testing type is regression testing. Once new changes have been implemented, the testing team uses a regression test to check what effect the change had on the software. A QA specialist can select some test cases and partially or fully re-execute the core software functionality units. Test cases that show any defects deserve the most attention.

Smoke Testing

QA teams conduct smoke testing between development and full-scale testing. Some call it build verification testing since the development team sends the project build to QA to check whether the code is crash-proof. One way to do this is to thoroughly analyze the basic functions to discover potential problems. Smoke testing results are used to decide if a build is stable enough to continue with other testing phases and whether to announce a production release.

Sanity Testing

QA performs sanity testing only when they don’t have enough time to run all test cases. When you need to check all crucial elements of your code and deliver it fast, sanity testing is shallow but can give you a basic overview of the product’s functionality. Sanity testing should not be used regularly. It is useful in scenarios where only minor changes are done or if something needs to be delivered urgently.

Exploratory Testing

One of the most commonly used testing models in Agile methodology is exploratory testing. It allows QA engineers to create individual tests and simultaneously test design and execution. When it is time to discover what software can do and if it can perform functions without bugs, unscripted tests are among the best solutions.

Nonfunctional Testing

Different software testing methodologies are necessary to ensure a software product’s quality. That’s why both functional and nonfunctional tests are essential for product development. Proper testing will guide your team toward the best solution, and keep them in compliance with product documentation and requirements.

Performance Group (Performance Testing, Stress Testing, Stability Testing)

All types of performance testing aim to verify the responsiveness as well as the stability of the system under a heavy load. Depending on the number of processes happening, the QA team can run a number of performance tests.

UI/UX Testing

When a product gets its design, a UI/UX expert should check the efficiency and user-friendliness of the software. Since this is one of the nonfunctional types of testing, its focus is on functionality from an average user’s perspective. This type of testing is quite different from others as it analyses interaction between a software product and its users.

Usability Testing

The goals of any usability test are to identify any issues, uncover opportunities for improvement, and learn more about user behavior. That’s why users are a key component of the process. They’re given the app while developers assess how it performs. Users also need to give their feedback on the interface, design, features, and ease of use.

Security Testing

Security testing is one of the types of testing in software engineering that inspects software security features. If the app is prone to attacks, hacks, or data leakage, a QA team can alert developers to secure it better.

Compatibility Testing

Another useful nonfunctional test conducted by the testing team is compatibility testing. Usually, the best time to do compatibility testing is during full-scale testing as it ensures that the app will work on diverse types of devices.

Localization Testing

The process of adapting a product to a different language or region is known as localization. Localization testing is customizing several important aspects of your software to work well in other parts of the world.

  • Time and date formats
  • Keyboard layout
  • Currency
  • Color schemes, symbols, and icons

Balancing Functional Testing and Nonfunctional Testing

While functional testing types check whether all functions and features are operating properly, nonfunctional testing checks other aspects of the software like reliability, design, security, and performance.

Types of Testing by Execution Method

Manual Testing

Manual tests are useful for validating the functionality and usability of a product without using any tools for automation. This type of software engineering testing can determine whether your software follows requirements and specifications. Every test scenario comes with detailed test cases that assess the software’s execution and test whether it delivers. It is recommended that a new application must be manually tested before implementing automated testing methods.

A pie chart depicts different manual testing concepts.
Any type of software testing can be executed both manually and through automation.

Automated Testing

Automated testing is an approach when automated testing software is used to execute test cases.

Automated Testing vs. Manual Testing

Every time you encounter software with a lot of test sessions and just a few iterations, it might be a strong candidate for automated testing. Also, automated testing is a better solution if you’re working on various user interface scenarios. When you’re working with complex functions, automated testing might take up a lot of your time and project resources.

Types of Testing-by-Testing Level

Every software, from basic to a multilayer solution, is complex as it is made from a number of functional components. That’s why it is so important to test every component or integration to get the best results. Diverse types of testing in the software department cover four elements of software:

  • Unit testing
  • Integration testing
  • System testing
  • Acceptance testing

Unit Testing (Code Level)

Units are the smallest functional parts of any software system. That’s why this type of software testing checks every single unit to make sure they meet all requirements. These tests have to be performed by engineers in the earliest development stages, as they can show any problems or malfunctions while the code is still in the making.

Integration Level Testing

Among the diverse types of testing in software development, integration testing is important as they are verifying the combined functionality of the individual units and their group interactions.

System Testing

Once the software functions as a whole, system testing is necessary to verify its functions and quality. System testing must be performed by a skilled testing team who use it in an environment that resembles real situations. Using various methods of testing is pivotal so that potential faults within a software product can be revealed with enough time for the development team to address them before the product is delivered to clients.

Acceptance Testing

The last stage of the testing process is acceptance testing. This ultimate step allows the development team to check whether the software complies with all user requirements. What’s more, the team can assess whether the software is ready to be shipped to the client at this stage. In this type of testing, the testing team is checking the overall system, not its components. It is of immense importance to examine the overall system’s quality, content, UI, and see whether there are any performance issues.


Testing methodologies sometimes sound easy to create and execute, but most are quite complex. QA teams must demonstrate not just technical knowledge and experience, but also business and industry insight that will help evolve the end product. Proper testing is instrumental in developing a new product.



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