Verification and validation are critical components of the software development life cycle (SDLC) that ensure the quality and reliability of the software being developed. Here’s a detailed explanation of both processes:

Verification

• Definition: Verification is the process of providing objective evidence that the design outputs of a specific phase in the SDLC meet the established requirements for that phase. It ensures that the product is being built correctly according to the design specifications.
• Purpose: The primary goal of verification is to confirm that the product’s design and development are on the right track before moving to the next phase. This process is typically focused on checking documents, design, code, and other artifacts.
• Method:
  • Reviewing and Inspections: Involves detailed reviews of design documents, code inspections, and walkthroughs to ensure that the outputs align with the specified requirements.
  • Third-Party Involvement: Sometimes, an independent third party may be involved in the verification process to provide an unbiased assessment. This can enhance the credibility of the verification process.
• Example Activities:
  • Code reviews
  • Design reviews
  • Requirements inspections
  • Test case reviews

Validation

• Definition: Validation is the process of evaluating the final product to ensure it meets the business needs and expectations of the stakeholders. It focuses on confirming that the software fulfills its intended purpose and functions correctly in the real-world environment.
• Purpose: The goal of validation is to develop a “level of confidence” that the software meets all requirements and user expectations. It often involves testing the software in environments that simulate real-world conditions.
• Method:
  • Testing: Various testing methods (e.g., functional testing, system testing, user acceptance testing) are employed to validate that the software behaves as expected under normal and exceptional conditions.
  • Iterative Improvement: Validation often reveals issues or areas for improvement, leading to software enhancements over time. This process helps refine the software and ensure it continues to meet evolving requirements.
• Example Activities:
  • System testing
  • User acceptance testing (UAT)
  • Performance testing
  • Field testing

Finding Backdoors through Structured Walkthroughs

• Structured Walkthroughs: This is a formal review process where developers and other stakeholders go through the design, code, or other artifacts to identify potential issues, including security vulnerabilities such as backdoors.
• Purpose: These walkthroughs help uncover hidden issues early in the development process, including unintentional or malicious backdoors that could compromise the software’s security.
• Participants: Typically involves developers, testers, security experts, and sometimes external auditors, to ensure a thorough examination of the software.

Summary

• Verification is about ensuring the product is being built correctly according to the specifications, while Validation is about ensuring the right product is being built, one that meets the user’s needs and expectations.
• Verification focuses on processes and artifacts during the development phase, whereas Validation focuses on the final product’s performance in the intended operational environment.
• Both processes are essential for producing high-quality software that is both secure and fit for purpose.