Writing this book would not have been possible without the encouragement and support I received from my family and colleagues. Their support gave me the energy and inspiration I needed to make the time to write this book after long days in the office and many business trips. I dedicate this book to my wife Marianne for her patience, support, and tolerance of my work and travel schedule, and to my children Suzanne and Adam, of whom I am very proud. The support I received from my colleagues at SAS has been invaluable. I would like to especially thank Michi Johnson, Christina Harvey, Cathy Traugot, and Stacey Hamilton for the contributions and support they provided.