First of all, in internal auditing I recommend not using either term. A nonconformance is a nonconformance and must be dealt with. I’ve seen too many arguments over the classification of a nonconformance when the emphasis should have been on fixing the problem.
Otherwise, a minor is an insignificant discrepancy. Perhaps a missing signature on a single document, or something like that. Minors will not impact the delivery of quality product, nor result in customer dissatisfaction.
A major is a breakdown in a system. Nonconforming product (including late delivery) will more than likely happen. Customer dissatisfaction is certain. I also do not believe that a certain number of minors result in a major unless, they indicate a breakdown in the system.
I worked with a company with over 10,000 controlled documents. Having three minors in document control would probably hailed as a victory. However, I also worked with a company that had less than 30 controlled documents. Three minors could be a disaster.
Thanks Dave B. Your first statement is strong and I think that is the same idea that troubles me if I use the two classifications. Although I have always used them in the past, I think it is time for an improvement!