Validation vs Verification in Medical Device Quality Systems

Two terms appear throughout any medical device quality management system, often used loosely in casual conversation but defined with precision in the applicable standards: verification and validation. For a distributor or institutional buyer reviewing a supplier's technical file, understanding what each term actually confirms, and what it does not, is a practical skill, not a pedantic distinction.

Verification: Did We Build It to Specification?

Verification asks a narrow, objective question: does the output of a given stage meet the documented requirements that were specified for it? A component's dimensions are checked against a drawing tolerance, a software function is tested against its written requirement, a packaging seal strength is measured against a defined minimum. Verification is typically carried out through inspection, test or analysis, and it compares a result against a specification that someone already wrote down. It does not, on its own, say anything about whether that specification was the right one to write.

Validation: Does It Meet the Actual Need?

Validation asks a broader question: does the finished device, used as intended, actually meet the user's needs and its intended use? Design validation is performed under actual or simulated use conditions, often involving representative users or clinical evaluation, and it closes the loop back to the original user requirements rather than to an intermediate specification. A device can pass every verification test in its design history file and still fail validation if the underlying requirements did not capture how clinicians actually use the product.

Why Process Validation Exists at All

The same split applies to manufacturing processes, and this is where the distinction becomes concrete for procurement. For many processes, such as machining a rigid part, every unit can be inspected afterward, so verification by inspection is sufficient. For others, such as sterilization, aseptic filling or certain welding and bonding steps, the critical attribute cannot be fully measured in the finished unit without destroying or compromising it. In those cases, process validation establishes, through documented testing under defined and challenged conditions, that the process reliably and reproducibly produces output meeting requirements, so that routine production can rely on monitoring the process parameters rather than testing every unit.

What a Buyer's Due Diligence Should Look For

When reviewing a supplier's quality documentation, the two terms point to different kinds of evidence, and a dossier that only offers one where both are expected is incomplete:

| Question | Evidence to expect | |---|---| | Does the product meet its written specifications? | Verification records: test reports, inspection data, measurement results | | Does the product meet the actual clinical or user need? | Validation records: design validation studies, usability or simulated-use data | | Can the manufacturing process be trusted without inspecting every unit? | Process validation protocols and reports (IQ/OQ/PQ or equivalent), revalidation triggers |

• A certificate of conformity or inspection report is evidence of verification, not validation.
• A change to a validated process (new equipment, a new material lot source, a relocated line) should trigger a documented revalidation assessment, not a silent assumption that prior validation still applies.
• Supplier documentation that uses "validated" and "verified" interchangeably, without specifying which activity and which objective evidence backs the claim, is a signal to ask clarifying questions before relying on it.

A Common Confusion Worth Avoiding

It is easy to read a strong verification result, such as a component passing every dimensional check, as if it already proves the device works for its intended purpose. It does not. The two activities are complementary and both are required in a mature quality system; neither substitutes for the other, and a dossier that is strong on one and silent on the other has not actually closed the loop.

The Takeaway

Verification confirms that a specification was met; validation confirms that the specification itself, and the resulting product or process, actually serves the intended use. For buyers and distributors, asking a supplier to show which type of evidence supports a given claim, rather than accepting the word "validated" at face value, is a small habit that meaningfully improves the quality of due diligence.

This is general educational information, not legal or regulatory advice; consult the current official texts and your competent authority.