Even if the two terms are often used interchangeably, they refer to two different types of analysis.
The main objective of verification is to check and ensure that each element of a device / system meets the appropriate specifications and standards. The tests are often done at a sub-system level.
On the contrary validation is concerned with the end product and – according to a FDA’s definition - it intends “to check that the device / system and its specifications conform with the user needs and the intended use(s)”
In the simplest terms, verification determines whether the product was built right (i.e. according to the defined specifications), while validation determines whether the right product was built[1].
In this respect several phases of the validation process involve making subjective assessments of how well the proposed system addresses real-world needs. Validation includes activities such as requirements modelling, prototyping and user evaluation.
Both, verification and validation, are important in medical devices, they complement each other, and regulatory bodies require well-documented verification and validation plans, test protocols and results to ensure the device meets requirements and is fit for the intended use. In addition, since the validation process tests the product in the real world and in the context of the application, it can find issues that the verification process was unable to identify.
[1] John Campbell – “Do you know the difference between verification and validation?” - https://sterlingmedicaldevices.com/