Model-driven development (MDD) has been promoted as a natural progression in the development of software systems, but the hype has significantly outweighed the available evidence of its successful use in practice. This book finally reveals the truth about MDD, explaining how it works in practice. Based on interviews with thirty successful MDD adopters and hundreds of responses to an in-depth survey, the text offers concrete, practical lessons and guidelines. Helping readers avoid the trap of starting a costly adoption process without first knowing the truth, the authors provide hard facts based on industry evidence that shows where, how, and why MDD works.