核查与验证

The distinction between verification and validation is fundamental to quality assurance in any complex engineering discipline, particularly software and systems engineering. Verification is an internal quality process focused on compliance with specifications. It involves activities like reviews, inspections, and walkthroughs of design documents, code, and requirements. The goal is to find defects early in the development lifecycle. For example, a code review verifies that the software adheres to coding standards and correctly implements a specific algorithm as described in a design document.

Validation, on the other hand, is an external quality process focused on fitness for purpose. It assesses whether the final product is effective in the operational environment for which it was intended. This typically involves testing the product with actual users or in a simulated real-world environment. For instance, user acceptance testing (UAT) is a validation activity where end-users test the software to see if it helps them perform their tasks efficiently and effectively. A system can be perfectly verified—meaning it has no bugs and meets all documented specifications—but still fail validation if those specifications were flawed or did not accurately capture the user’s true needs.

Barry Boehm’s work emphasized that these two activities answer different questions and are crucial for delivering a successful product. Neglecting verification leads to a buggy, unreliable product, while neglecting validation leads to a product that, while technically sound, is ultimately useless to its intended audience. The two processes work in tandem to ensure both correctness and usefulness.