Short presentation of the ITM architecture
You can use a ITM to collect data and monitor the system. Learn more about the type of agents through the information provided here.
At its core, the browser provided by ITM presents data that is gathered by agents.
ITM agents are characterized by the following definition:
"The agents (referred to as managed systems) are installed on the system or subsystem requiring data collection and monitoring. The agents are responsible for data gathering and distribution of attributes to the monitoring servers, including initiating the heartbeat status." (Extract from the ITM documentation)
There can be various kinds of agents: agents to monitor operating systems or specific applications, or specifically tuned agents (that is, using the Universal Agent interface). The following diagram, taken from the ITM documentation, describes both the architecture and the deployment process of agents:

TEMS = Tivoli® Enterprise Monitoring Services
TEP = Tivoli Enterprise portal