In the foreword to Supply Chain Structures, Professor Paul Zipkin notes three global changes that have enabled the recent vast developments in the field of supply chains. Moreover, these changes may be only the beginning and more change is likely in the fast-moving field of supply chain management. These global changes are: the explosive growth of the Internet; the growth in free-market economies with the corresponding political interest in global economic stability; and the emergence of a global managerial culture focused on performance, quality, and service. Professor Zipkin goes on to say "In Supply Chain Structures, the editors Jeannette Song and David Yao have collected a spectrum of approaches to these challenges from some of the leading scholars of supply chains, from both the academic and commercial worlds. Each of the articles offers an interesting and illuminating way to think about the key issues in supply chain management. Some also offer practical techniques to solve important problems. Together they provide an excellent survey of the current state of the art in research and practice."