While the structure and organization of the text remains essentially the same as in the fifth edition, the current edition includes several new topics. The new material is aimed at enhancing the technical content of the book, and for that reason is more likely to appeal to engineering students and advanced business students. The biggest addition is a section in Chapter 2 on Box-Jenkins models. The Box-Jenkins methodology has proved itself to be a valuable forecasting tool in the right setting. I balked at including this material in past editions because of its complexity. In this edition, I tried to develop a self-contained discussion at a comparable technical level to the rest of the text. Hopefully, this 20 or so page addition has accomplished this goal. I would appreciate feedback from those of you that add this material to your coverage of forecasting.

Another addition suggested by current and past reviewers was to include Robin Roundy's power-of-two policies in Chapter 4. While this work has had a major impact on inventory modeling, again there was a question about whether the discussion could be at a level commensurate with the rest of the book. What I have done is to treat power-of-two policies in the context of the simple EOQ model only (as abstracted from one of Roundy's papers). In this way, the student can get a sense of why these policies are able to provide such effective approximations without getting into the details of the more advanced analysis.

In addition to these changes, I have added several new exercises in the early chapters. Much of the expository material has been updated, and many new Snapshot Applications included. My thanks go to all of the loyal users of earlier editions, to the editorial staff at McGraw-Hill, and to the reviewers of the fifth edition including Elif Akcali, University of Florida; Moshe Dror, University of Arizona; Michael Erickson, Albertson College; Serge Karalli, California State University at Sacramento; Reza Khorramshahgol, American University; Rakesh Nagi, University of Buffalo; and Kevin Taaffe, Clemson University.