Result of several years of research and development, the software COMPARE of 1A3i is able to identify all differences between 2 versions of a schema. It brings an innovation that no other software offers today: the software COMPARE of 1A3i analyses the differences including parts of the schematic that have been moved, turned, resized. It allows to validate or ignore each difference and to associate comments. The software COMPARE of 1A3i automatically produces a report of differences showing images and comments. This software is available in 3 editions: “Standard”, “Professional” and “Expert.