Hi,
Technical monitoring PIMOn do monitor the business systems messages also, have you checked under message monitor,
check the demo here Central PI Monitoring with SAP Solution Manager
Other cases we do have some Pi message Monitoring keyfigures available on BPMon , check the ppt attached in the doc New key figures for BPMon & BP Analytics - new exception and automation rate key figures for ERP plus new content for FSCM, APO and CRM
Thanks
Jansi