Introduction
Title 21 Part 820 of the Code of Federal Regulations (CFR) details the requirements for the design and production of medical devices. These strict, comprehensive requirements are in place for good reason; we want these devices to work. CFR Title 21 Part 820.10c points to ISO 13485 Clause 7.3 for medical product design constraints (GPO, 2026). Included in Clause 7.3 are requirements for the verification and validation of products and processes, two methodologies that help ensure the production of optimal-quality medical devices.
What exactly are verification and validation?
Verification and validation (sometimes called V&V) are key practices performed during product development that can identify deficiencies in the design or production process, enabling flaws to be corrected before market release. While ISO 9000:2015 (NIST, 2015) more formally defines these terms, basically, verification confirms that the design requirements have been met, answering the question “did we build the device correctly?”, while validation confirms that the product satisfies the intended use, addressing the concern, “did we build the correct device?”.
The verification process includes product inspection and testing to confirm that the design outputs (drawings, software, and final product) meet the design inputs (user needs and safety/regulatory specifications). Validation involves user acceptance testing (ensuring real users are happy with the product) and conducting clinical trials for new or modified devices.
ISO 13485:2016 Section 7.5.6 (NIST, 2016) says validation is required where “the resulting output cannot be or is not verified by subsequent monitoring or measurement…” (that is, if we are not conducting 100% inspection, for example) … “and, as a consequence, deficiencies become apparent only after the product is in use” (this can result in patient injury, product returns, complaints and worse). It is much more desirable, efficient, and far more frugal to validate a process than to perform 100% inspection of all products before shipment.
Sitting in on V&V
Let’s take a look at V&V concepts as if we were using them to build a ready-to-assemble chair. Verification would ensure that we included all the right parts in the right places on the completed chair (legs, back, seat, fasteners), while validation would involve sitting in the chair to confirm it doesn’t fall apart. If we diligently followed the instructions, but the chair still crumbles, this likely means that the directions are wrong or missing details (maybe they forgot to tell us to secure the bolts)! We would then update the instructions according to what we found. On the other hand, if we discover that we did not follow the instructions, that could mean we need to learn more about putting chairs together (do training) or potentially add visual aids to make the chair “production process” easier to understand.
Key types of validations
Two essential elements of product development are design and process validation (NIST, 2016). Design validation, conducted to ensure that the design meets user requirements, ideally should be performed as early as possible, starting with a prototype (sample product produced by engineers) and repeated as the product design matures. Timely validation helps identify and correct design deficiencies before final manufacturing begins, demonstrating that the early bird can indeed prevent the worm from ending up in a medical product. When the design is ready for production, process validation confirms that the manufacturing process consistently creates an appropriately designed product. If product inconsistencies are identified, updates to manufacturing process instructions, additional employee training, or the provision of tooling/fixtures can be implemented to achieve consistent, high-quality manufacturing.
Consequences of insufficient validation
In 2024, medical device recalls reached their highest ever (Dubinski, 2025), with two recent cases having particularly tragic consequences. Boston Scientific recalled its Watchman Access System (part of a stroke-prevention apparatus) when 17 deaths and 120 injuries occurred during procedures conducted without positive (forced air) ventilation (Wallace, 2025). In addition, Philips withdrew its bi-level positive airway pressure (BiPAP) machines, which are critical for patients with respiratory issues and sleep apnea, after an error causing machine shutdown resulted in 13 injuries and eight deaths (Reuter, 2025). These issues demonstrate why robust functional, system, and user testing during V&V is essential to ensure the safety of ourselves and our loved ones.
In addition to the tragedy of patient deaths and injuries, medical device recalls can have a severe impact on manufacturers. Lawsuits, as well as the cost of product refunds and repairs,s can be financially devastating to a business, and the resulting damage to a company’s image can squash future sales. Recalls also come with increased regulatory oversight, leading to heightened compliance requirements such as added inspections that require more people, costing the company even more money. Together, these factors can potentially put a company out of commission. Why risk these consequences when a robust verification and validation process could prevent them from happening?
Conclusion
Medical device regulatory standards continue to become more rigorous (Crawford, 2015) as field failures occur and lessons are learned. With technological advancesmakinge therapeutic devices even more intricate, scrutiny of product design and manufacturing is all the more vital. V&V leads to identification and correction of potential product failures before a device is released to the market, demonstrating why we need verification & validation of medical devices to ensure consistent, high-quality medical products are released to the public.
Discussion