As we all know specifications are essential for any product and not only affect the validation and verification of a product but everything that is the product. We saw in the minisim this week one of the set backs of the high specificity in a requirement. Should specifications reflect the limits to which any individual component can be to function properly, with buffers of course, giving more room for certain variations but increasing the risk? Do specifications have to be the guidelines for validation or testing in QC or are they the outer limit? Is it okay for specification to have a one sided bound as opposed to double bound, such as in the case with the better coefficient of friction? (assuming it doesn't affect the product in a negative way)
As you mentioned, specifications are very essential to the product but only that it is essential to the DSD as well. To submit the DSD to the FDA, the DSD has to be detailed and have the components of the product with its specifications. Wide or no accurate upper and Lower limit of the critical component of the product will rise questions and more verifications and validation testing will be required to answer the FDA questions.
In my experience, when formulating brand-new specifications, many individuals draft a document, then send it to the supplier to see if it is feasible for them. If yes, then a contract can be made. If not, then they set up a meeting and discuss if it is possible to address certain items on the specification or in the supplier's processes. Additionally, the supplier and the company both share their inspection methods as both should align. If both parties are inspecting with different tools or in different ways, this can yield to nonconformances, where there weren't any to begin with. Additionally, I've seen one-sided bounds do exist but they are usually part of non-critical measurements and are only used as references. Sometimes the supplier requests these one-sided bounds in order for them to comply with the specification at hand. In certain instances, one-sided bounds cannot exist within the product; it all depends on the situation.
If you are creating specifications for a product, I think you should still take into account a range for the product that will be incorporated with your project. If you make the specifications too general, it can create confusion and increase the risks especially if the product will be used on human patients. Unfortunately, I think specifications need to be have a small range as to have a clear and concise idea for the project. If an issue arises, the specifications can always be adjusted with additional testing to ensure there are no additional risks. As long as the product is still proven to be safe and efficient, I don't see a problem with having more concise specifications and then altering them later in the case an additional material is needed to be included to the product.
