The logic of Manufacturing Resource Planning (MRP II) is im­ plemented in most commercial production planning software tools and is commonly accepted by practitioners. However, these peo­ ple are not satisfied with production planning and complain about long lead times, high work-in-process, and backlogging. As many researchers have pointed out, the reason for these shortcomings is inherent to the methods that are used. The research community is thus eager to find more sophisticated approaches. This book is an attempt to compile some state-of-the-art work in the field of production planning research. It includes mate­ rial that somehow dominates the existing MRP II concept. 15 ar­ ticles written by 36 authors from 10 countries cover many aspects related to MRP II. All papers went through a single-blind refere­ eing process before they were selected for being published in this book. When we received papers for this issue, we discovered that MRP II is a topic about which not only management scientists show interest. As the list of authors proves, industrial engineers, computer scientists, and-operations researchers from academia as well as practitioners have contributed to this book. This, we hope, makes the book of value for a broad audience. We thank all authors who submitted papers. And, we are in­ debted to Dr. Werner Muller from Springer for his support in this book project.