Modem information technology has created new possibilities for more sophisticated and efficient control of supply chains. Most organizations can reduce their material flow costs substantially. Inventory control techniques are very important components in this development process. A thorough understanding of relevant inventory models is a prerequisite for successful implementation. I hope that this book will be a useful tool in acquiring such an understanding. Nearly ten years ago I wrote a Swedish book on inventory control. This previous book has been used in courses in production and inventory control at several Swed­ ish engineering schools and has also been appreciated by many practitioners in the field. Positive reactions from many readers have occasionally made me contemplate writing a new book in English on the same subject. Encouraging support of this idea from the Kluwer Editors Fred Hillier and Gary Folven finally convinced me to go ahead with the project. The result is this new book, which in many ways differs from its Swedish prede­ cessor. Some differences are due to recent developments in inventory control. Fur­ thermore, this new book is in a sense more theoretical. In particular, it is to a larger extent focused on creating a good basic understanding of different possible ap­ proaches when analyzing inventory models.