In BMC PATROL, a PATROL Agent procedure carried out at preset intervals on each monitored computer to discover application instances. When an instance is discovered, an icon appears on the BMC PATROL interface. The application class includes rules for discovering processes and files by using simple process and file matching or PSL commands. Application definition information is checked against the information in the PATROL Agent process cache, which is periodically updated. Each time the PATROL Agent process cache is refreshed, application discovery is triggered.