With careful attention to diet, primarly meaning avoiding fats, your dog can live a normal life span. My aunt and uncle had a mini schnauzer
with chronic pancreatitis for half of her 18 years. Yes, that's eighteen; it's not a typo. :-)
Pancreatitis is also one of the most painful conditions a dog (or person) can have. I hope that your dog's pain is well treated when he has a flare up. How many times has he been hospitalized, and how many years has he had this problem?