Lots of EBS users ask same question in OTN forum: How we can Monitor our EBS’s System Health.

Actually this question already answered in Steven Chan blog, for details please click here

You can find many usefull artcile on upper links.  By the way for your System Health you can also check&follow below metalink notes:

Oracle E-Business Suite Diagnostics Test Catalog for 12.1.1 [ID 783319.1]
Best Practices for Securing the E-Business Suite [ID 189367.1]
E-Business Suite Diagnostics Installation Guide [ID 167000.1]
E-Business Suite Diagnostic Tools FAQ and Troubleshooting Guide for Release 11i and R12 [ID 235307.1]
Applications 11i Health Check After Maintenance [ID  283976.1 ]