incident management clarification

Hi all,

        I had configured INCIDENT MANAGEMENT in solman 7.1 sp03,

        I am able to create msg in my development and production systems and can be viewed in solman ITSM.

       but still need some clarification, as how exactly it will work.

       who is message processor, reporter, key user etc.

       and how does a user in the production system view the status of the issue raised by him. do i need to give access to the solman system ITSM.

       why we require to create a BP for user in the satellite system. even if we dont create any BP in the system we can still create a msg in the satellite

      system so what is the purpose of that.

looked around in the documents and forums but could not come to a conclusion.

thank you