Can Characterization Substitute for Design Verification?

Q: We have characterized a material change to our medical device and have confirmed there’s no impact to any of our design inputs or outputs. Do we still have to formally perform Verification and Validation (V&V)?

In other words, is the evidence of no impact from characterization acceptable to justify not doing V&V?

A: Yes — but let’s back up a bit and put this answer in context.

Design verification proves the appropriateness of a design output specification relative to a design input. It answers the question — is this the correct output specification?

Most design verification is done by analysis, but some of it is done by inspection, measurement or testing.

In your case, you’ve decided to make a material change; therefore you are changing a design output specification. As part of your characterization, you’ve determined that the output specification for the new material is consistent with applicable design inputs.

Your analysis also has determined that the new material output specifications have no adverse impact on the other design inputs or outputs associated with the device. If you have documented your characterization studies and your impact analysis, you have performed design verification. And based on that data, it appears you believe that design validation (performance and functionality and usability, etc. testing) is not required.

[pullquote align=”right” cite=”” link=”” color=”” class=”” size=””]All design changes must be verified and validated, unless you can document that verification alone is appropriate.[/pullquote]

All design changes must be verified and validated, unless you can document that verification alone is appropriate — which it appears you’ve done in this case. You should always do design verification for every change, as well as an impact analysis. You also should always demonstrate the correctness or appropriateness of every design output specification.

What’s not always required is performance and functionality testing to prove that — with the new output specification — the new finished device will perform and function as intended and meet your user’s needs.

So, based on what you’ve told me, you have performed design verification and have a scientific justification as to why you don’t believe you need to do design validation. Just make sure your characterization and analysis are well documented, even if done via some sort of design or peer review process.

Answered by Denise Dion, Vice President of Regulatory and Quality Services for EduQuest, who served 18 years at the U.S. FDA as an expert field investigator, helped to develop FDA’s Quality System Inspection Technique (QSIT), and was a member of FDA’s Design Control Inspection Strategy Team. Denise also is the lead instructor of EduQuest’s two-day training class on Design Control for Medical Devices: Meeting FDA’s 21 CFR Part 820.30 Rules for Quality Design and Manufacturing.


Leave a Reply

Your email address will not be published. Required fields are marked *