Software Testing Tutorial #27 - Verification and Validation in Software Testing

Summary

This tutorial explains the key differences between verification and validation in software testing, a crucial concept often addressed in interviews. It highlights how verification (static testing) involves reviewing documents and code without execution, while validation (dynamic testing) involves executing the software to test its functionality. The tutorial emphasizes the importance of early defect detection in verification to reduce costs and effort. It also covers various testing techniques such as code reviews for verification and unit, integration, and system testing for validation, providing examples and tips for explaining these concepts confidently in interviews.

Takeaways

• 🔍 Verification is static testing, while validation is dynamic testing.
• 📄 Verification involves reviewing documents and code without execution (e.g., code review), focusing on identifying defects early in the development phase.
• 🚀 Validation includes executing the actual software or application to check for defects in the functional behavior (e.g., launching an e-commerce website).
• 📊 Verification checks if the software aligns with requirements and design documents, while validation ensures the final product meets user needs.
• ⚙️ Verification helps in identifying issues early in the development process, reducing the cost and effort of fixing defects.
• 🛠️ Code reviews, walkthroughs, and inspections are examples of verification techniques used to find issues before code execution.
• 🔧 Validation is performed during testing phases like unit testing, integration testing, system testing, and acceptance testing.
• 💡 In verification, defects are found by analyzing documents and code, whereas in validation, bugs are found during software execution.
• ⏳ Dynamic testing (validation) is conducted once the code is complete, while static testing (verification) happens throughout development.
• 💰 Identifying defects early through verification reduces the cost and complexity of fixing issues later in the software development lifecycle.

Q & A

What is the main difference between verification and validation in software testing?

Verification is static testing, where the code is not executed but documents and code are reviewed manually. Validation is dynamic testing, which involves executing the code to check if the software meets the required specifications.

What is static testing in the context of software verification?

Static testing refers to the process of manually checking documents, code, or designs without executing the software. It includes activities like code reviews, inspections, and walkthroughs.

What is dynamic testing in the context of software validation?

Dynamic testing involves executing the software to validate its functionality. It ensures that the software behaves as expected when running, such as testing an e-commerce website by launching and interacting with the application.

How is the V-model related to verification and validation?

In the V-model, verification activities are performed on the left side, where documents and designs are reviewed. Validation takes place on the right side after the code is ready and executed in various testing phases such as unit, integration, and system testing.

Why is it important to find defects early during verification?

Finding defects early in the verification phase saves time and cost. If issues are identified before coding, they can be corrected before they propagate to the design or code, reducing the complexity and cost of fixing them later in the development cycle.

What is an example of verification in software testing?

An example of verification is a code review, where developers manually inspect the code for adherence to coding standards without executing the program.

What is an example of validation in software testing?

An example of validation is launching an e-commerce website, navigating through it, and performing functional tests like adding items to the cart to ensure the site works as expected.

What types of defects are typically found during verification?

Verification helps identify defects in documentation, design flaws, or missing requirements. These issues can be caught early without executing the software.

What are some testing techniques used in verification?

Common testing techniques in verification include code reviews, walkthroughs, inspections, and technical reviews, which do not involve running the code but focus on reviewing the structure and design.

What testing techniques are used in validation?

Validation techniques include dynamic tests such as unit testing, integration testing, system testing, acceptance testing, and regression testing, all of which involve executing the software.