Re: Difference between Non-Conformance & Deviation-definitions please
What you're describing as a "concession" is in fact synonymous with "deviation" or "waiver" in many instances. These things are defined locally, and there is no universal definition for any of them. They can apply to products or processes.
I just don't see how "conceding" and "deviating" could be synonymous, and I didn't mean to use the words synonymously in my previous post.
The word "concession" is used throughout the ISO 9001 and 13485 standards (the two quality systems standards I work with) relative to nonconforming product. Neither standard discusses deviation. The FDA Quality System Regulation discusses deviation relative to process, however.
I define "concession" as a granting waiver, while "deviation" is the departure from a process or standard. In other words, the specification tells me that the part is nonconforming, but I concede and accept the nonconformity. The nonconforming material procedures should define the requirements for acceptance of materials on concession.
Like I said earlier, I agree with your definition of nonconformity - a failure to meet a specification. A nonconformity could exist in a product or a process. In either case, nonconformities result from the failure of an existing system. You could say that the definitions for nonconformity and deviation are very similar, but deviation doesn't always result from or even relate to a nonconformity.
I've seen "acceptance on concession" called, "Use As Is", "Conditional Approval", "Waiver" and the list goes on. So, I agree that some companies will call this "Accept on Deviation". My point was that once any of these are executed, the parts in question are no longer nonconforming, but I don't believe that this is the type of "deviation" that the OP is trying to address in a deviation procedure.
In my industry, medical device manufacturing, a "Deviation Procedure" typically addresses how the company will handle planned deviations from procedures - or specifications.
There could be a need for a temporary deviation from a specification for a raw component. Or, there could be a need for a temporary deviation from a procedure like I described earlier.
In either case, the deviation procedure should provide for an adequate review and approval of the deviation and include a review of the possible impact the deviation could have on the product as well as any validation requirements.