Removing unused resources from an Ideal environment is one of the tasks of an Ideal Administrator. Moreover sometimes the Destinations member in ADROUT cannot be ported during upgrades, so it must be manually rebuilt.
Is there an easy way to find out if the Output Destinations defined in ADROUT are actually used by Ideal applications and users?
CA Ideal and CA IPC do not keep statistics on output destinations.
However you can use CICS statistics or a CICS monitor (if installed) to check if a printer (terminal) has been used.
Note that if ADROUT is shared among several CICS regions, all regions could print to the same device.