It is very clear that both of these processes are done after the product design is nearly complete. These processes are there to make sure the needs for a customer are filled and that the product works as intended to. When you would do that is pretty self explanatory; constantly as and after you make a design, and before you finalize it.
Any project within the medical device industry requires some sort of design verification and validation work in order to ensure that the product is safe and effective. Timing can be very critical to the project since launching date is directly dependent on when DV is executed. The team starts of by performing a couple of studies in order to understand where does their project stand and how is it compared to other products in the market in order to determine what performance aspects are subject to improvement. Once those performance aspects are highlighted, the team researches what can be done to the current product to improve it and starts doing some undocumented preliminary testing to try out different solutions to get to the desired goal. The next step would be documented Pre-DV to prepare the product for DV testing that is going to be used in the FDA 510(k) to prove that the product is safe and effective for its intended use. After the team performs everything prior to DV and feels confident that the DV samples that are going to be manufactured represent a representative of the final finished product and that the team is confident that it is going to pass all functional testing based on previous data then Design Verification and Validation can be executed. The reason behind it is that any failures would have to be documented at this point for the FDA so the team confidence has to be really high before going into DV.
Verification and validation is the process of investigating that a medical device satisfies and meets specifications and standards and it fulfills the required purpose. That being said, verification takes place while the product is still under development. At every stage while the device is under development you question if the device is built right by verifying that the device meets all its requirements. Validation involves assessment of the device to make sure that are its operational needs in the device can function under realistic environmental conditions.
In a nutshell, verification should begin at the development stage of the device and continue throughout the life cycle of the project, making sure that each output matches the input or specification. While validation is performed upon completion of the device if using the product in living people that requires clinical study.
Some companies start the verification and validation at the beginning of the project depending on the device and continue to address verification and validation activities throughout the product life cycle in order to reduce the risk associated with medical devices.
I agree that there should be a thought on verification in the early stages of development, but I don't agree that products should be verified too early on in the project itself. Issues such as scope creep and design changes occur frequently where it would be best to characterize the product prior to saying that you are verifying performance. Characterization would be a good idea to understand the prototype from for a proof of concept and generation of acceptance criterion in verification/validation, but it does not limit you to use process equivalent products to perform user/mechanical testing. Also, you do not need (generally) a statistically driven sample size that is required by regulatory bodies to prove the product performs as intended.
All that being said, verification should be completed once the product is characterized and there will be no further design changes until the product launches in the market where sustaining activities or line extensions can occur. Both V&V stages can be completed in conjuncture since they are usually independent from one another unless there is a need to verify performance of a finicky system or a shared sample size is used to reduce cost of process equivalent parts.
Looking up the definition of validation and verification, the FDA describes validation as proving that “specifications conform with user needs and intended use(s).” and verification as proving that “design output meets design input.” (Source: https://www.fda.gov/media/116762/download ) My understanding of this is that verification is making sure that the design process and is sound and that validation is testing the device to make sure it works. Thus, I think verification and validation should act as phase gates at the end of the design phase and implementation phase, respectively. My reasoning is that meeting FDA requirements is a criterion which needs to be met in both phases.
Validation and verification are independent procedures. The project manager uses them to make sure that they have made the right project in the correct way. Verification is about confirmation to its specifications which is an internal process. Validation is about customer expectation and it is often an external, subjective process. Verification comes before validation. Both validation and verification are performed at the end of the project where everything is put into place.
In the context project management I think that validation and subsequent verification have to be carried out by the project management team throughout the total project and not at a particular time. Validation and verification essentially make sure that the project deliverables are met at a correct and timely manner. Each stage of the project has to be evaluated and the techniques involved are more or less what validation is about. PMs and supervisors verify that validation is carried out properly. But in the context of the design stage these concepts seem to be different in meaning.
Design verification always comes before design validation. Using the PDCA acronym, verification would fall under C (check), whereas validation would fall more under A (act). Verification is a way to check that all inputs = outputs, meaning the current project design meets all of the needs and requirements for the device. In order to verify that all outputs, or requirements, are successfully met, a verification protocol must be created. A verification protocol consists of making a test for each output and ensuring that each test passes. If a certain test fails, the project team may have to redo the test, come up with a different test, or take a few steps backward and adjust the design of the device. If all tests pass, this is where validation can come into play. Validation is not always needed following verification, but it is essential for products that underwent any significant changes after verification or for products that require a clinical trial. Validation protocol is nearly the same as verification protocol, requiring tests for each output. The main difference is that these tests are more specific to the user's needs and are therefore conducted using living people or cadavers.
