Functional verification requires more than executing test cases and collecting pass or fail results. Reliable verification depends on measurable evidence that the design has been exercised, observed, checked, and evaluated across the intended functional space. Verification metrics provide that evidence by quantifying coverage, granularity, manual effort, effectiveness, completeness, and reusability. These measurements help clarify whether verification activity is producing real confidence or simply generating simulation volume. Granularity defines how deeply design behavior is observed and measured. A transaction-level view may confirm that high-level operations complete correctly, while detailed coverage at the interface, state, protocol, or signal level can expose corner cases that broader observation may miss. Manual effort measures the engineering cost required to create tests, inspect results, maintain infrastructure, and debug failures. Reducing manual effort through automation, reusable components, and structured checking improves scalability without weakening technical quality. Effectiveness and completeness determine whether a verification strategy is strong enough to ex...