Supervising producer Calvin Clements Jr. left the show after season 10, and was replaced for seasons 11 and 12 by the returning Arthur Bernard Lewis, who remained a writer on the show until its end. Lewis was thus reuniting with Leonard Katzman and David Paulsen. However, Paulsen left "Dallas" at the end of the 11th season (to join rival soap " Dynasty"), and was replaced as the show's producer first by Howard Lakin for season 12, and then by longtime associate producer Cliff Fenneman for the final two years. Lakin spent seasons 13 and 14 as supervising producer.