The terms bottleneck and constraint are frequently mentioned in context of production delays. Companies are often apprehensive to having constraints in the production process. However, these con-straints could be opportunities to improve the throughput and punc-tual delivery with the help of suitable procedures. But what are suit-able production planning and control systems for constraints? And how can buffers be used to keep the constraint working? This book is supposed to give an overview of the current production planning and control systems and how they deal with constraints and buffers.