Thanks, Steve! I talked about the options with my boss & he thinks it will be extremely rare. He said to go with the -1 for now, but I really like your idea about adding a - of the business key instead. That's a great way to handle the problem of having more than 1 unidentifiable dim. I hope my boss is right and this won't happen. As long as he's happy, I'm happy. Thanks so much for your response!