Reverse engineering (reverse engineering = development, mechanical engineering, technology) is about obtaining information about the design of existing complete systems and processes by closely examining their structures, states and behavior. In this way, the usual design process is turned around and now starts with the finished product in order to enable (re)design at the end. Thus, usually for verification purposes, a true-to-scale copy of the object is made from the data obtained, which can then be used for further work if necessary. The principle of reverse engineering is used for both hardware and software, and is actually also the idea behind many sociological considerations. The variety of applications is really enormous, and it also finds many uses in mechanical engineering. For example, the technical requirements of historical systems can be analyzed and checked for compliance before commissioning, which may be risky due to unknown operating parameters. Numerous metrological methods are used for reverse engineering procedures, including laser scans and stylus instruments.