The book "DigiTwin: An Approach for Production Process Optimization in a Built Environment" offers a comprehensive analysis of the Digital Twin concept and its application for optimizing production processes in a built environment. It is aimed at professionals and students in the fields of engineering and IT, providing in-depth knowledge about the digital representation of physical production systems. The methodology for creating and utilizing Digital Twins is described in detail, with a focus on improving factory processes such as factory planning, investment planning, bottleneck analysis, and internal material transport. The book also addresses the challenges of process planning and provides insights into future developments in this area. With a transdisciplinary approach, the technology of Digital Twin is presented as modern and forward-looking in both research and practical application.