Changing or retooling is often seen as a necessary nuisance. However, this is precisely where the key to flexible production lies. Large production runs are rarely as advantageous as they may seem at first glance, as they often lead to high inventory levels and long lead times. Quick retooling or changing is the focus of this book. The authors present SMED, a proven method that drastically reduces changeover times. The emphasis is not on cost savings or higher machine utilization. Instead, optimizations in the setup process are leveraged to allow for more frequent changeovers, smaller batch sizes, and ultimately lower inventory levels. The authors deliberately use the term "changing" rather than "retooling," as SMED also helps to reduce changeover times in areas outside of production.