Everything You Need to Know About Software Testing Methods

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Before software is shipped for public or commercial use, programmers spend hours ironing out every bug, and the product remains in limbo until all stakeholders are satisfied.

Silicon Valley software giants like Google and Facebook will often ship popular products to market despite the low-priority bugs in their software. Investors and millions of loyal users will tolerate software updates and temporary kinks with the free products these companies offer, even when these bugs lead to data breaches and bad publicity.

The majority of software companies don’t have this luxury. Customers expect products to do what they claim on the sales page, and are rightfully alarmed about the vulnerability of their business' intellectual property and sensitive data. With so many software development options available, customers don't think twice about jumping ship if the product stinks of wasted time and money. Software businesses must therefore perform rigorous testing on their products before releasing to customers. These tests will offer the following insights:

  • Highlight differences between the original concept and final output.
  • Verify the software works as the designers planned.
  • Assess features and quality.
  • Validate the end product meets customer requirements.

Testing follows a strict blueprint to optimize workload, time, and money while providing stakeholders with essential information to move the product forward. The goal is to facilitate a positive end-user experience by keeping a thorough quality assurance (QA) program. Given the high stakes for developers, QA managers are some of the top earners in the technology industry. Testing usually follows the these steps:

  1. Requirement analysis, where managers outline a plan to put a suitable test strategy in place.
  2. Tests begin and results undergo analysis.
  3. Any defects are corrected, and the software goes through regression testing (a system to check that the program still works after modifications).
  4. A test closure report which details process and outcomes.

Individuals can become certified software testers through organizations such as BCS, The Chartered Institute for IT, ISTQB® (International Software Testing Qualifications Board), and ASQ (formerly the American Society for Quality).

Software Testing Methods

Black and white box testing are two fundamental methods for judging product behavior and performance, but there are other methods as well:

  • Black box testing: Also called functional or specification-based testing, this method focuses on output. Testers aren’t concerned with the internal mechanisms. They only check that the software does what it’s supposed to do. Knowledge of coding isn’t necessary, and testers work at the user-interface level.
  • White box testing: This method uses coding experience as part of the test procedure. When a product fails, testers go deep into the code to find the cause. Software developers will do this themselves, as they're entrusted to determine how the product should work. White box testing is also referred to as "structure-based" or "glass box" testing.
  • Static testing: Testers examine the source code and any accompanying documentation but don’t execute the program. Static tests start early in the product’s development during the verification process.
  • Dynamic testing: The software is executed with various inputs, and testers compare outputs with expected behavior.
  • Graphical user interface (GUI) testing: Testing characteristics such as text formatting, text boxes, buttons, lists, layout, colors, fonts, font sizes, and so on. GUI testing is time-consuming, and third-party companies often take on the task instead of developers.

Test Levels

Different levels of testing are used to identify areas of weakness and overlap in each phase of the software development lifecycle.

  • Unit testing: Developers test the most basic parts of code like classes, interfaces, and functions/procedures. They know how their code should respond and can make adjustments depending on output.
  • Component testing: This step is also known as "module" or "program" testing. It’s similar to unit testing but contains a higher level of integration. Modules of the software are tested for defects to verify their individual function.
  • Integration testing: This identifies errors when the modules are integrated. Different methods for integration tests include "bottom-up", "top down", and "functional incremental".
  • System testing: Components of a project are tested as a whole in different environments. System testing falls under the black box method and is one of the final tests in the process. It will determine if the system is prepared to meet business and user needs.
  • Alpha testing: Internal staff test the software at the developer’s site in a simulated or actual environment. After that, developers rectify bugs and other issues.
  • Beta testing: Also known as field testing, clients test the product on their own sites in real conditions. Clients may offer a group of end-users the opportunity to test the software via prerelease or beta versions. Feedback on possible improvements is then sent to the developer.
  • Acceptance testing: Also under the scope of black box testing, clients test software to find out if the developer has fully developed the program to fit desired specifications.

Test Types

Different types of software tests are designed to focus on specific objectives:

  • Installation testing: The test engineer and the configuration manager conduct this test to ensure the end user can install and run the program. It covers areas like installation files, installation locations, and administrative privileges.
  • Development testing: This implements a range of synchronized strategies to detect and prevent defects. It includes static code analysis, peer code reviews, traceability, and metrics analysis. The aim is to reduce risks and save costs.
  • Usability testing: User experience comes under the spotlight with this test. It measures how well the GUI's ease of use. The test checks accuracy and efficiency of functions and the emotional responses of test subjects.
  • Sanity testing: This indicates if the software is worth the time and cost to continue further tests. If there are too many flaws, more aggressive tests won’t follow.
  • Smoke testing: Smoke testing reveals basic failures that are serious enough to prevent release. When this is carried out on a new build, it is called a "build verification" test.
  • Regression testing: When the system undergoes modification, regression testing monitors unexpected behavior. It points out adverse effects on modules or components.
  • Destructive testing: Testers input abnormal entries and discern the software’s ability to manage unexpected input. This shows developers how robust the program is at error management.
  • Recovery testing: When hardware or other functions fail, this test shows how well the software can recover and continue operation.
  • Automated testing: This performs functions difficult to implement manually. It uses specific software to run tests and provide data on actual versus expected outcomes.
  • Compatibility testing: Software must run in different computing environments, so this checks compatibility with different systems. For example, testing the software with various operating systems and web browsers.
  • Performance testing: This is an in-depth test that examines software performance in different scenarios. Information about responsiveness, stability, resource allocation, and speed is gathered. Subtests such as volume, capacity, and spike testing play a part in this process.
  • Security testing: This measures the software’s ability to protect users’ security. This means authorization functions, authentication, confidentiality, integrity, availability, and nonrepudiation.
  • Accessibility testing: This is not the same as usability testing. This determines the extent to which users of differing abilities, learning and physical disabilities included, can use the software.
  • Internationalization and localization testing: Results show how the software can adapt to different languages and regional demands. This includes adding components for specific locations and text translation.