Eliyahu M. Goldratt was an educator, author, physicist, philosopher and business leader, but fi rst and foremost, he was a thinker who provoked others to think. Oft en characterized as unconventional, stimulating, and "a slayer of sacred cows," he urged his audience to examine and reassess their business practices with a fresh, new vision. Dr. Goldratt is best known as the father of the Theory of Constraints (TOC), a process of ongoing improvement that identifies and leverages a system's constraints in order to achieve the system's goals. He introduced TOC's underlying concepts in his business novel, The Goal: A Process of Ongoing Improvement, which has been recognized as one of the best-selling business books of all time. First published in 1984, Th e Goal has been updated three times and sold more than 10 million copies worldwide. It has been translated into 40 languages.