| March 1998 | Formation of "Atena Gesellschaft für Engineering Services mbH" (Joint-Venture of MTU Aero Engines and Brunel International) |
| January 2002 | MTU Aero Engines takes over ATENA shares from Brunel |
| July 2003 | Formation of Atena India Private Limited |
| April 2004 | Named into "Atena Engineering GmbH " |
| July 2005 | Assystem became Shareholder of Atena |
| June 2008 | BU Technology & Systems renamed to "Silver Atena Electronic Systems Engineering GmbH" |
| April 2012 | SILVER ATENA became 100% subsidiary of Assystem |
| February 2019 | Assystem Germany rebrands as Expleo |
| Oktober2019 | "Silver Atena Electronic Systems Engineering GmbH" renamed to "Silver Atena GmbH" |
