The 5 phases of testing software (plus Agile testing)

By Indeed Editorial Team

Published 11 July 2022

The Indeed Editorial Team comprises a diverse and talented team of writers, researchers and subject matter experts equipped with Indeed's data and insights to deliver useful tips to help guide your career journey.

Creating and delivering sophisticated computer programs and mobile applications is a complex and layered process. Before developers release digital products to market, the products undergo many phases of testing to ensure they fulfil their intended function and meet the expectations of clients and consumers. It's important that software development professionals know the stages of program testing and understand why each phase is necessary. In this article, we explain the phases of testing, the life cycle of testing and the reasons to apply the testing process.

What are the phases of testing software?

At each phase of testing, testers and inspectors evaluate even the tiniest details to ensure they function correctly. The iterative, cyclical nature of the testing procedures means the process can become repetitious. To break up this pattern, testers divide the process into phases, which allows examinations, workflow and documentation to operate more effectively. There are typically five main phases of testing a software build, including static tests, unit tests, integration tests, system tests and acceptance tests.

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What is the software testing life cycle?

The software testing life cycle refers to the examinations testers and developers perform to determine the quality and functionality of a computer program or application. It's a defined, methodical practice that software developers can follow to ensure a product reaches quality standards before bringing it to market, although some companies may implement slight variations on the standard format. The life cycle is a sequence, layered into several focused phases. Each phase is important in establishing specific goals and results. The phases follow a sequential order since the objectives of each phase directly affect the effectiveness of the next.

5 main phases of software testing

Testing begins with the static phase. To simplify the testing process, the four latter phases of software testing are sometimes split into secondary phases, known as the verification stage and the validation phase. The verification phase encompasses the unit and integration tests, while the validation stage includes the system and acceptance tests. The verification stage involves white-box testing, which means the central components are visible and require the attention of professional testers. Validation requires that black-box testers examine central systems where processes aren't visible. Within these parameters, testers conduct detailed phases of inspection.

Here are the five main testing phases:

1. Static testing

Testers perform the static testing method to identify defects or potential issues in a software application without executing the code. To reduce or avoid making early errors, they use the software's supporting documentation to perform manual and automated reviews of the code. They look through the requirement specifications for potential problems, such as redundancies or ambiguities. The purpose of static testing is to foresee issues before developing the software system.

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2. Unit testing as part of the verification phase

Unit testing is the primary test phase for all software applications. This process examines all of a system's modules separately to check that they function correctly and perform at maximum capacity. This stage of testing requires experienced testers to examine the most minute details of the program, as unit evaluations may vary substantially from one another. If there are any modifications in the software code, unit testing is important to help identify any resulting issues and resolve them quickly and efficiently.

3. Integration testing as part of the verification phase

This phase of testing involves the verification of modules and examination of how they operate collectively. To ensure modules are functioning cooperatively, examiners typically test them separately and then as a group. This method of testing allows examiners to identify any problems that may arise when multiple components operate simultaneously to complete functions. In cases where individual components seem to be performing properly, developers can conclude the entire software is functional only when examiners successfully complete the integration phase.

4. System testing as part of the validation phase

During the validation process, the system testing phase uses simulations to create real-world operational environments that examine how applications perform when testers subject them to full-function tests. Under close observation, each software build undergoes a series of rigorous tests to ensure it's performing optimally as testing reaches its final phase. Examiners use client requirements to benchmark their results and verify that the product meets expected performance standards. System testing is important because it ensures that the software meets all of the client's requirements.

5. Acceptance testing as part of the validation phase

Sometimes testing groups may enlist the help of nonprofessionals such as software consumers and novices to use newly developed software. The acceptance phase asks these testers to examine the product in the same way an end-user might experience the product in a real-world environment. These tests can sometimes identify requirements that have yet to become implemented and misunderstood during the development process but don't affect the normal function of the software when examiners test it to its maximum tolerance. When examiners complete and mark this phase as passed, the quality assurance team can proceed past testing to launch the product.

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Why are software testing phases important?

The different phases of software testing are important for helping developers evaluate the various characteristics of a program and determine if the application is ready for release. They allow developers to address flaws in software design and functionality and security as soon as they discover them, which can prevent costly changes later. The battery of targeted examinations can help identify issues or defects in an application before developers approve them for mass production. Identifying problems early can streamline the quality of production, avoid releasing and recalling defective products and preserve an organisation's reputation.

Other types of software testing

Companies sometimes require additional testing phases or methods to ensure optimal performance throughout a product's life cycle. These testing phases include the following:

  • Performance testing: Testers subject software to performance testing to evaluate how it copes under different conditions and workloads. This method has several subcategories, including load testing, which examines a software's functionality in simulated real-life user scenarios, and stress testing, which subjects software to strenuous performance levels to see how well it handles these demands before failing.

  • Regression testing: To help ensure consistent functionality, developers apply regression testing to the software. When developers add an update or modification to a program, testers check that all previous systems remain functional.

  • Usability testing: This test examines the software from the end user's perspective and evaluates the ease of use of its interface and design. Usability looks at navigation and simplicity to ensure the application presents the consumer with a rewarding or enjoyable experience.

  • Compatibility testing: Software requires different specifications to run on various operating systems and platforms. Compatibility testing runs the software in different operating systems, mobile platforms and web browsers to see how well it performs in those environments.

  • Security testing: Security testing evaluates how well software copes with threats from hackers, viruses and malware. Testers look for weakness in the code that could jeopardise a user's privacy, then secure any flaws using extra code.

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What is Agile testing?

Agile testing has become the preferred model for some testers in software development and quality assurance. The flexibility of Agile testing in comparison to other testing structures helps keep the process on track even when developers introduce adjustments or modifications into the testing cycle. This method can also contribute to speedier results in terms of project feedback and completion. Agile testing involves the following stages and principles:

  • Requirement assessment: This is the primary inception stage where testers assess a project's requirements for feasibility. During this phase, stakeholders may evaluate the project, submit queries and offer input about the project's vision and outcome.

  • Planning: The testing plan requires an experienced team of testers to conduct a detailed analysis of the project from inception to completion. In this phase, the team carefully scrutinises and documents all considerations, including the financial budget, person-hours and other required resources.

  • Test case development: Testers use requirements as building blocks for test cases to ensure authenticity and achieve results based on the client's expectations. Developers and testers work closely to generate an accurate memorandum of data.

  • Release readiness: Testers often use automated tools to test the software's readiness for real-world use. By simulating the end user's interaction with the product, testers can evaluate a product's performance and readiness for release.

  • Execution: In this phase, the testing team executes the test cases under careful conditions to verify the program's health. If testers detect any bugs, issues or errors at this stage, the testers report them back to the development team for further analysis.

  • Cycle closure: During this final stage of testing, all members of the testing teams gather for a general evaluation of the completed operation to debrief their experience of the entire project. Team members share insights on difficulties they encountered and propose ways to overcome challenges in future endeavours.

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