As Prof. Simon mentioned in his lecture, the validation process consists of design validation and process validation. In a design validation, you assess whether the product meets all of the user needs, and this validation is usually conducted by a selected group of end users. The key to a successful design validation is first of all getting good VOC feedback in the beginning of the project to create a user needs list, and second of all keeping users engaged throughout the development of the product, by showing them prototypes and having them assess these prototypes to ensure that the product is on the right track and meets all of their needs. If all the work was done thoroughly and correctly leading up a design validation, the design validation should really be just a final check confirming that all user needs were met, and the risk of failing the validation should be low. For a process validation, you assess whether the supplier is able to consistently and reliably produce the product that you have designed to the specifications you have set. The key to a successful process validation once again starts right at the beginning of the project. Assuming the company is using a supplier to manufacture their product, the supplier must be assessed for their capability to achieve the process validation that will be required by the company. It is also very important that the supplier and the design team collaborate and have DFM discussions throughout the design and manufacturing process to alleviate any process capability concerns before actually executing the process validation.

A successful validation program brings together engineering, manufacturing, regulatory compliance, and quality assurance to develop test solutions that are unique to each application. Developers of medical devices must validate the product design to ensure that it meets the user's requirements. Design validation should be more than bench testing. Ensure that animal models, simulated anatomical models, finite element analysis and human clinical studies are considered.

Also, manufacturers of medical devices must validate any process, including any associated equipment and software, whose entire output is not or cannot be fully verified by inspection. Examples of these type of processes are sterilization, packaging systems, soldering processes, and automated systems.Critical processes that may require validation include material handling, assembly, chemical or biological processing, purification, testing, cleaning, packaging, labeling, storage and distribution.

Process validation is defined as the collection and evaluation of data, from the process design stage through commercial production, which establishes scientific evidence that a process is capable of consistently delivering quality product. Process validation involves a series of activities taking place over the life cycle of the product and process. Process validation has 3 stages: Process Design, Process Qualification, and Continued Process Verification. In the Process Design, the commercial manufacturing process is defined during this stage based on knowledge gained through development and scale-up activities. In the Process Qualification, the process design is evaluated to determine if the process is capable of reproducible commercial manufacturing. In Continued Process Verification, Ongoing assurance is gained during routine production that the process remains in a state of control. A successful validation program depends upon information and knowledge from product and process development. This knowledge and understanding is the basis for establishing an approach to control of the manufacturing process that results in products with the desired quality attributes. Manufacturers should understand the sources of variation, detect the presence and degree of variation, understand the impact of variation on the process and ultimately on product attributes, and control the variation in a manner commensurate with the risk it represents to the process
and product.
Based on the FDA website, there are steps to make a design validation better. Each manufacturer shall establish and maintain procedures for validating the device design. Design validation shall be performed under defined operating conditions on initial production units, lots, or batches, or their equivalents. Design validation shall ensure that devices conform to defined user needs and intended uses and shall include testing of production units under actual or simulated use conditions. Design validation shall include software validation and risk analysis, where appropriate. The results of the design validation, including identification of the design, method(s), the date, and the individual(s) performing the validation, shall be documented in the Design History File.

I think a successful validation process involves repetition and numerous trials of testing. I haven't had experience in the industry with medical devices, but I have done research where we were required to do experiments and make sure that our results were real. We ended up repeating the experiment multiple times to make sure there is consistency. I think that the same idea would apply to testing medical devices. Repeating tests a couple of times will confirm a validation test. If the tests aren't the same every time, then you know something is wrong.

In my opinion, I don't agree with the previous comment If I understand correctly about numerous trials. Instead, a company/manufacturer should have an established procedures with a defined operating conditions (units, lots, time etc) like @markabdelshahed has mentioned. First of all, conducting too many trials could be a waste of time/money if you can conduct much less trial but still prove the efficacy. Secondly, having an inconsistent amount of trials can make the process seems "fishy" or makes others question "why do you have to add more trial for this products?" "Maybe it's not working as good as others" etc. A lot of time, there's not a "woring"/"not working" situation, it could be in scalar such as 80%, 90% efficiency unit etc so you would have to run stats and by adjusting the "n number", you can make a mistake of p-hacking and it would not be considered as reliable.

To make a successful validation process you need to clearly state your inputs and make sure they match your user's needs. You must think critically about what each input means so that you can design a test that covers that. You must also clearly define what is a pass or fail for each input. If you don't clearly state this in the validation process you could potentially miss something. I believe if you clearly define the inputs and the pass/fail requirements, it will be easy to determine if your inputs match your user's needs. A successful validation process would clearly define inputs and user needs to ensure that a product is properly validated.

Agree with this in terms of having an established amount of lots, units, and time for running the validation. If you are conducting a validation you would want to prove that a set amount of lots or units is sufficient in proving the output equals the input. You run these trials during the Operational Qualification and Performance Qualification of the validation. The Performance Qualification is key just because you need to prove that production lots or units are producing the intended outputs. Most of the time these lots and units will actually be shipped to customers. Therefore, it is highly important to ensure that you are validation is indeed sufficient in terms of the # of lots or units you are testing and that these products meet the criteria.

A successful validation process contributes significantly to assuring the medical device quality and proves that the product produced is fit for its intended use. Quality, safety, and efficacy are all built into the product. I believe from the design stage through commercial production, validation process should establishes scientific evidence that the medical device is capable of consistently delivering.

A successful validation process will ensure that each requirement for a use is fulfilled, essentially end user needs are met. An important aspect of a validation plan is knowing your target customer/end user so that you can confirm that the needs they have are met. In addition to this there are multi functional teams that are responsible for the validation process as package integrity tests are conducted ranging from temperature excursion, humidity, shock/vibration, corrosive environments, shipping lane validations, and altitude. These factors can all influence the final product and therefore need to be characterized and documented for validating product.

A successful validation process will make sure to follow all the company and the FDA rules and will ensure that the user needs and the company needs are met. The user needs are to make sure that user has everything they expect in the product, while the comapny needs are to make sure that the company makes profit. A good validation plan to target your customer knowing who they are and what they need.

Validation in a way is an abbreviated version of the verification. It will allow the user to guarantee that the device or fixture is still functioning at its necessary caliber. It can begin with something as simple as checking the plug socket for correct voltage and become as detailed as making sure that ever FDA process is guaranteed to be completed and also that gauges and calibrations are checked. This will ensure that old products are not being used. This will also decrease that a audit will find anything permanently damaging to the company.

At my company, I work in Integration. Our job is to conduct validation tests for software and scanner updates. From what I've experienced, I noticed that to conduct and produce a successful and sufficient validation, being as extensive and critical as appropriately possible is key. This means conducting extreme and a wide variety of trials that are repeatable is essential. In addition, noting all details that may be important to note throughout the process is equally important. Of course, conducting such trials would take a good amount of time which is why excluding steps that are not necessary for the purpose of the validation is almost as important as determining the necessary steps. It is also important to note that validation does not necessarily end at the end of the testing. Keeping track of bugs and findings that were not noticed during validation is crucial. Not only does it provide developers to make alterations to fix them, but it also helps improve on future validation protocols and tests so that not as many issues arise later on.

One of the task I had to work on as an intern was validation. The first step for a successful validation is that everyone on the team does their part in a timely manner. For example, the team ensures the IQ and ect is complicated so the validation can be done as soon as possible. Another step to be successful is to look at previous validations or find validations from other sites on the same machine. A lot of times, another site has done the validation on the machine you are about to validate. It will allow you to use their validation as a template. The next step is to pre-determine the statistical aspect of the validation. How many samples will be used? Is it enough to ensure the quality of the machine is good? Utilize statistical programs such as Minitab.

A proper validation process should revolve around the patient by ensuring that the medical device under development meets the user's needs. An important aspect of design validation, as mentioned in lecture, is the application of clinical human studies in order to analyze how a demographic of patients respond to the applied medical device. An important point mentioned in the MDDI Campbell article posted this week is that a validation process must include the manufacturing controls and conditions (which explains why validation is often confused with verification). Injection molding a medical device for example requires distinct parameters such as temperature and pressure which can only be applied across a specific range throughout processing. It is overall necessary to include these factors in validation simply because they determine the outcome/performance of the product, which in turn is decided by the patient.

If the patient is not satisfied with the performance of a clinical device, then validation will have to re-examine the specifications of the device, which can include going back to the input-output relationship (the verification). This explains why the validation process can take several years to fulfill and even result in preventing a product from being launched to market. Are there any scenarios in which design validation can be avoided, such as in the case of a low-medium risk device? The Campbell article also specifies the importance of including the equipment and the facility at which manufacturing takes place, known as installation qualification (IQ). What type of controls or environmental maintenance needs to be accounted for to satisfy the IQ requirements?

Reference:
Campbell, Bryan "Validation Can Make a Product Launch a Sure Thing" (2011) Product Development Insight