Since the beginning of 2011, mergers and acquisitions have reached a total value of $309.6 billion. In other words, 69% more than in 2010 at the same time. Mergers and acquisitions are a major source of name changes for companies. Total-Elf, Adecco, EADS, Hewlett Packard-EDS... Many large companies have been created through mergers and acquisitions or are growing through this process. Because the merger and acquisition process has a psychological impact on the members of the original entity, it is undeniable that this process requires specific management that takes into account the importance of relationships, which are largely underestimated in favor of economic considerations.