Top questions with answers asked in MNC on Quality Assurance (QA) Testing

Interview questions on Quality Assurance (QA) asked in multinational corporations (MNCs), along with explanations:

1. What is the difference between black box testing and white box testing? Can you provide examples of when each might be used?
   • Black box testing:
     • Black box testing focuses on testing the functionality of a software application without knowing its internal code structure or implementation details.
     • Testers approach the software from an external perspective, treating it as a black box where inputs are provided, and outputs are observed based on predefined specifications or requirements.
     • Examples of black box testing techniques include equivalence partitioning, boundary value analysis, and use case testing.
     • Use black box testing when:
       • Testing user interfaces, where the internal logic is irrelevant.
       • Conducting acceptance testing to ensure the software meets customer requirements.
   • White box testing:
     • White box testing, also known as structural or glass box testing, involves testing the internal logic, code structure, and implementation details of a software application.
     • Testers have knowledge of the internal workings of the software, including source code, algorithms, and data structures.
     • Techniques such as code coverage analysis, path testing, and branch testing are commonly used in white box testing.
     • Use white box testing when:
       • Verifying code coverage to ensure that all statements, branches, and paths are tested.
       • Conducting unit testing to validate individual components or modules of the software.
2. Describe the various phases of the software testing life cycle (STLC). How do they contribute to ensuring product quality?The Software Testing Life Cycle (STLC) consists of several phases, each contributing to ensuring the quality of the software product:
   • Requirement Analysis: Understanding and analyzing the requirements to identify testable features and define test objectives and scope.
   • Test Planning: Developing a test plan that outlines the testing approach, strategies, resources, schedule, and deliverables.
   • Test Case Development: Writing test cases based on requirements, covering positive and negative scenarios, and ensuring test coverage.
   • Test Environment Setup: Setting up the test environment, including hardware, software, tools, and test data required for testing.
   • Test Execution: Running test cases, recording test results, identifying defects, and reporting them to the development team for resolution.
   • Defect Tracking and Management: Logging defects in a defect tracking system, prioritizing them based on severity and impact, and tracking their resolution.
   • Regression Testing: Re-executing previously executed test cases to ensure that recent changes or fixes have not adversely affected existing functionality.
   • Test Closure: Evaluating the test cycle, analyzing test metrics, preparing test summary reports, and obtaining stakeholders’ approval for product release.

   Each phase contributes to product quality by ensuring that requirements are met, defects are identified and addressed, and the software functions as intended under various conditions.

3. Can you explain the difference between regression testing and retesting? How do you prioritize test cases for regression testing?
   • Regression Testing:
     • Regression testing involves re-running previously executed test cases to ensure that new code changes or modifications haven’t adversely affected existing functionality.
     • It aims to detect defects introduced by recent modifications or fixes and ensure that the software remains stable and reliable.
     • Regression testing is typically automated to save time and effort, especially in large and complex projects.
   • Retesting:
     • Retesting focuses on verifying that a previously identified defect has been fixed correctly after the development team has made the necessary changes.
     • Test cases related to the specific defect are re-executed to ensure that the issue has been resolved and that no regression has occurred.
     • Retesting is often performed manually and is part of the defect verification process.
   • Prioritizing Test Cases for Regression Testing:
     • Prioritize test cases for regression testing based on factors such as:
       • Impact: Prioritize test cases covering critical or frequently used functionalities.
       • Risk: Prioritize test cases related to areas with a higher likelihood of regression.
       • Dependency: Prioritize test cases that cover modules or functionalities affected by recent changes.
       • Coverage: Ensure that a representative set of test cases covering different functionalities and scenarios is included.
     • Use techniques such as risk-based testing, impact analysis, and traceability matrix to prioritize test cases effectively.

These detailed explanations should provide a comprehensive understanding of Quality Assurance (QA) Testing concepts and help in preparation for QA Testing interviews.