Here's the KPI definition. The key part for me is:
"The formula incorporates Opponent’s Winning Percentage, Opponent’s Strength of Schedule, the Game Result, Scoring Margin, Pace of Game, Location of Game (Home/Away/Neutral) and the Opponent’s KPI Ranking. The value for each game is divided by games played for the overall KPI Ranking.
"The rankings can be made to include only a certain subset of games as well. Home KPI, KPI vs Top 100, November KPI, and any combination one can dream up are possible."
http://www.kpisports.net/about/definitions/
I like it because each season starts with a blank slate, and because it's kind of a hybrid between the old RPI (results) and some of the other notable rankings (KenPom, Sagarain, ESPN's BPI), but is based more on actual game results, not on how a team looks or how efficient they are. I prefer judging teams on wins and losses, not how good they look, or how many stars their recruits had (BPI).