Hi Wahida.
It is possible to set up usage logging in SSA. This is explained here
http://support.pb.com/help/analyst/12.1/admin_guide/en/index.html#concepts/configuring_usage_statistics.html#shared_properties
and here
http://support.pb.com/help/analyst/12.1/admin_guide/en/index.html#tasks/report_usage_statistics.html
They capture the user name, their session ID and also the maps they have viewed. The logs can be quite large as they capture the entire usage (e.g. every individual map render and feature request a user makes from SSA to the Spectrum Server) during their session. A single user may generate 100's of log entries during their session. However they can provide a wealth of information on how SSA is used.