Out of 99 Warning Letters issued to Medical Device companies in 2013 (up to July 3rd, 2013), 50 have contained observations relating to Design Control (21 CFR 820.30) deficiencies, with a total of 85 observations. The three subcategories that received the most attention are (f)Design Verification (12 observations, or 24% of the Medical Device related Warning Letters), (g) Design Validation (19, 38%), and (i) Design Changes (24, 48%).
Design Verification1 is the exercise of verifying that the final design meets the requirements for the product. In other words, “did we engineer something that does what we originally asked for?” This is done through formal review of the final design, specifications, calculations, and simulations that trace back to the requirements. Design Verification can be thought of as a final sanity check at the end of the engineering design cycle. A traceability matrix is a highly effective tool for this purpose.
Design Validation2 may sometimes be confused with Design Verification and it is important to understand the distinction. Design Validation involves taking actual products and testing them in actual-use environments to verify that they can actually perform as required. This testing is performed as a formal, thoroughly documented study to ensure that nothing was overlooked during the verification stage, and that acceptable operational environments do not cause any performance issues.
Design Changes3 , or change control, is an art unto itself. At any point, if there are any changes to the raw materials used, components of the products, or manufacturing process changes, then change control actions are required “…for the identification, documentation, validation or where appropriate verification, review, and approval of design changes before their implementation4.” This particular subsection may receive the highest number of observations because the regulation is somewhat open ended with regards to the level of effort required in these actions. In general, change control can leverage a significant amount of previous verification and validation efforts by conducting risk assessments for the changes to be made, and comprehensive studies of how changes can potentially affect the product as a whole.
All of these aspects of Design Controls require thorough documentation, which should be included in the Device History File (DHF). These are several of the major phases in Medical Device design and production. All these phases feed into one another and build off of previous efforts, and so it is important to understand what can be leveraged from previous phases and what efforts are unique and required in each subsequent phase. If you would like to discuss Design Control efforts - particularly verification, validation, and change control programs - then please contact us.
121 CFR 820.30(f)
221 CFR 820.30(g)
321 CFR 820.30(i)
421 CFR 820.30(i)