Decisive potential in business is a question of process capability, rather than production capability. Process capability in business requires real-time systems for optimization. Business-IT needs to be developed from telecommunications and ERP to real-time services, which are not offered by the prevailing ERP systems. This book shows how modern information technology Manufacturing Execution Systems (MES) becomes the prerequisite for process capability of the company on the basis of many practical examples. It describes the requirements for optimized MES. It gives an overview of the efficiency potentials and different applications of MES.