Calculate ABC Codes

It is taking over 2+ hrs to run the Calculate ABC Codes even when I do a print preview only. I am running it for only 3 days but would like to run it for 1 year. Does it become a performance issue with the number of parts or the date range selected? Seems like it is calculating all of our parts even for three days which is still taking a long time. Any recommendations if we have over 100,000 parts?