Tools for Monitoring the System 
Use
In the SAP System, you find a set of tools for displaying detailed information on user sessions, work processes, and on the servers in your SAP System.
If you want to work with these tools, choose in the SAP initial screen Administration ® System Administration, or enter transaction S002.The initial screen for system administration appears. The tools are available under Administration and Monitor.
There are also test programs that you can use at operating system level to monitor the message server or the gateway.
Features
The following functions are available:
Overview of SAP application servers
Monitoring and Testing the SAP Message Server
Displaying and Controlling Work Processes
Display and Manage User Sessions
Using SAP Gateway Monitor in SAP System
Monitoring RFC Resources on the Application Server