SA XT for web access : System Architect XT : System information for Administrators : Session and execution timeouts
  
Session and execution timeouts
There are two timeouts that may be set for users working in the System Architect XT environment. A session timeout automatically logs out users if they do not perform any activities or read new pages in a System Architect XT session for a certain period of time: see Setting session timeout.
An session timeout will cause a page to timeout if the ASP.NET script being used to get information from the repository does not return anything by a certain amount of time. You may change both of these timeout settings in the web.config file, found in the System Architect XT directory on the server. You can also adjust the timeouts with the IIS console or the ASP.NET Configuration option in Visual Studio.