Software testing lifecycle


Software testing plays a critical role in ensuring the quality, reliability, and usability of software applications. It involves systematically uncovering defects and errors, to enhance the overall user experience. In this comprehensive guide, we will explore the lifecycle of software testing. From planning and designing test cases to executing tests and reporting defects, each phase of the testing process contributes to delivering high-quality software. Whether you are a software developer, tester, or simply interested in understanding the testing process, this article will provide valuable insights into the intricate world of software testing.

What is the Software Testing Life Cycle?

The Software Testing Lifecycle (STLC) is a systematic approach to testing software applications. It consists of a series of well-defined phases that help ensure the quality and reliability of the software being developed. Each phase in the STLC has specific objectives, tasks, and deliverables, and it helps in identifying defects and ensuring that the software meets the specified requirements. In this article, we will explore the various phases of the Software Testing Lifecycle in detail.

All About Software Testing: Life Cycle Phases And Different Stages

Software testing is a critical process that ensures the quality, reliability, and functionality of software applications. It involves systematically evaluating a software system or component to identify any defects, bugs, or errors that may affect its performance. Software testing typically follows a set of well-defined phases to facilitate thorough and structured testing. Let’s explore the common phases of software testing:

Requirement Analysis: In this initial phase, testers collaborate with stakeholders to understand the software requirements and identify the scope of testing. They analyze the functional and non-functional requirements to gain a clear understanding of the expected behavior and performance of the software.

Test Planning: Test planning involves creating a comprehensive test strategy and test plan. Testers define test objectives, select appropriate testing techniques, determine the test environment, and allocate resources. They also identify the test deliverables and establish timelines and milestones.

Test Design: In this phase, testers develop test cases and test scenarios based on the requirements and design documents. Test cases outline the steps to be executed, the expected outcomes, and the test data required. Testers may also create test scripts or automate test cases for efficient execution.

Test Environment Setup: A suitable test environment is prepared to replicate the production environment where the software will be deployed. This includes setting up hardware, software, networks, databases, and other dependencies necessary for testing. Testers ensure that the test environment closely resembles the real-world conditions.

Test Execution: Testers execute the test cases according to the test plan and record the actual results. They compare the actual outcomes with the expected outcomes and document any discrepancies as defects. Test execution may involve manual testing, automated testing, or a combination of both, depending on the testing approach and available tools.

Defect Tracking: Detected defects are logged into a defect tracking system, which captures essential information such as the defect description, severity, priority, and the steps to reproduce it. Testers communicate the defects to the development team for resolution, and the defect tracking system is used to track the progress and status of each defect.

Test Reporting: Testers compile and document the test results, including the number of test cases executed, the number of defects found, and other relevant metrics. Test reports provide stakeholders with valuable insights into the quality of the software and help in decision-making regarding its release readiness.

Test Closure: In the final phase, a test closure report is prepared to summarize the overall testing activities, achievements, and lessons learned during the testing process. Testers evaluate the effectiveness of the testing process and identify areas for improvement. Test closure ensures that all necessary testing activities are completed, and the software is ready for release or further development iterations.

These phases may vary depending on the software development methodology employed, such as waterfall, agile, or DevOps. However, the fundamental objective of software testing remains consistent: to validate the software against specified requirements and deliver a reliable and high-quality product to end-users.

Planning Phase 

The planning phase sets the foundation for successful software testing. It involves defining the scope, objectives, and strategies for testing. The testing team collaborates with stakeholders to understand requirements, identify risks, and prioritize test cases. Test plans are created, outlining the testing approach, test environment, resources required, and timelines. This phase also involves establishing communication channels, setting up test environments, and defining roles and responsibilities.

Design Phase 

In the design phase, the testing team focuses on developing effective test cases and test scenarios. Test cases are created based on requirements and functional specifications. The team identifies test data, outlines preconditions and expected outcomes, and determines the testing techniques to be employed. The test cases are organized into test suites and prioritized based on risk analysis. Additionally, test environments and test data are prepared to simulate real-world scenarios. The design phase ensures comprehensive test coverage and enables efficient execution in the subsequent phases.

Execution Phase:

The execution phase involves the actual execution of test cases and the evaluation of software functionality. The testing team executes both manual and automated tests based on the defined test cases. They record test results, compare actual outcomes with expected results, and identify deviations. Defects and issues are logged into a defect-tracking system for further analysis and resolution. The execution phase may require multiple iterations to ensure adequate test coverage and identify as many defects as possible. Test logs and execution reports are generated to document the progress and provide insights for further improvement.

Defect Tracking and Management Phase:

In this phase, the testing team focuses on managing and resolving defects found during the execution phase. Defects are tracked using a defect tracking system, which helps prioritize, assign, and monitor their resolution. The team collaborates with developers to provide detailed defect reports, including steps to reproduce and expected results. The developers investigate the reported defects, fix them, and provide updated software versions for retesting. The defect tracking and management phase involves a continuous feedback loop between the testing and development teams to ensure timely resolution and closure of defects.

Retesting And Regression Testing Phase :

After defects are fixed, the testing team performs retesting to validate that the fixes are effective and have not introduced new defects. Regression testing is also conducted to ensure that existing functionalities have not been affected by the changes. Test cases are selected strategically to focus on the modified areas and critical functionalities. Automated testing tools are often used to streamline the process and improve efficiency. The retesting and regression testing phase helps maintain software stability and ensures that defects are not reintroduced into the system.

Test Closure And Reporting Phase 

In the final phase, the testing team wraps up the testing process and prepares a comprehensive test closure report. The report includes a summary of the testing activities, test coverage, defect metrics, and an overall assessment of the software’s quality. The stakeholders review the report, and based on the findings, make decisions regarding software readiness for release. The test closure phase also involves knowledge transfer sessions.

Entry And Exit Criteria For Software Testing:

Entry and exit criteria are essential components of software testing. They define the conditions that must be met before testing can begin (entry criteria) and the conditions that must be fulfilled for testing to be considered complete (exit criteria). These criteria ensure that the testing process is systematic, well-defined, and effective. In this article, we will discuss the entry and exit criteria for software testing.

Entry Criteria For Software Testing:

Test Plan Approval: The test plan, which outlines the scope, objectives, and approach of testing, should be reviewed and approved by relevant stakeholders before testing can begin.

Test Environment Readiness: The test environment, including hardware, software, network configurations, and test tools, should be set up and ready for testing. It should closely resemble the production environment to ensure accurate testing.

Test Data Availability: Sufficient and representative test data should be available for testing. The test data should cover a wide range of scenarios, including positive, negative, and boundary cases.

Test Case Preparation: Test cases should be designed, documented, and reviewed. Test cases define the specific conditions to be tested and the expected results. They should cover all aspects of the software under test.

Test Scripts/Tools Readiness: If test automation is involved, the test scripts or test automation tools should be prepared and validated. The scripts should be able to execute the test cases accurately.

Unit Testing Completion: Unit testing, performed by developers, should be completed successfully. Unit testing helps identify and resolve defects at the code level, reducing the number of issues encountered during system-level testing.

Functional Requirements Specification: The functional requirements specification, describing the desired behavior and functionality of the software, should be available and understood by the testing team.

Defect Management System: A defect management system, such as a bug tracking tool, should be set up and ready to capture and track defects identified during testing.

Exit Criteria For Software Testing:

Test Execution Completion: All planned test cases should be executed, including functional, integration, performance, security, and other types of tests. The test execution should cover a significant portion of the software functionality.

Defect Closure: All identified defects should be fixed, retested, and closed. Defect closure involves verifying that the fixes are effective and do not introduce new issues.

Test Coverage: The planned test coverage should be achieved, ensuring that all critical functionality and business scenarios have been adequately tested.

Test Execution Results: Test execution results, including test logs, test reports, and defect reports, should be reviewed and analyzed. The reports should provide insights into the quality and stability of the software.

Exit Criteria Metrics: Specific metrics, such as defect density, test coverage, and pass/fail rates, should meet the predefined thresholds or targets.

System Stability: The software should demonstrate stability, with no critical issues or showstoppers affecting its functionality or performance.

Customer/Client Acceptance: The software should be reviewed and accepted by the customer or client, indicating their satisfaction with the software’s quality and meeting their requirements.

Regression Testing: Regression testing, which ensures that changes or fixes do not introduce new defects, should be conducted and passed successfully.

It is important to note that entry and exit criteria may vary depending on project requirements, organizational processes, and industry standards. Defining and adhering to these criteria help ensure that testing is conducted in a structured and controlled manner, leading to higher-quality software and increased confidence in its reliability.


The Software Testing Life Cycle (STLC) is an integral part of software development, ensuring the quality and reliability of software applications. By following a structured and systematic approach, software testing helps identify and rectify defects and issues early in the development process. This results in higher-quality software, reduced costs, and increased customer satisfaction. STLC is an essential practice for delivering software that meets and exceeds user expectations.