Oracle E-Business Suite 12.2 has several technology stack components.  Each component has its own ORACLE_HOME:

• Oracle Fusion Middleware
  • Oracle WebLogic Server (WLS) 10.3.6
  • OHS (WebTier) 11.1.1 and Oracle Common (Common Modules)
• Application Server (OracleAS)
  • Forms and Reports 10.1.2
• Oracle Database
  • Oracle Database Server 11.2 or 12.0

Each of these technology stack components can be patched individually.  But what do you use to patch them?  For a quick cheatsheet, see:

• Oracle E-Business Suite 12.2 Patching Technology Components Guide (Note 1355068.1)

References

• Oracle E-Business Suite 12.2 Concepts Guide
• Oracle E-Business Suite 12.2 Maintenance Guide

Related Articles

• Enabling an EBS Global Diagnostics Trace
• Creating a Maintenance Strategy for Oracle E-Business Suite
• May 2017 Update to E-Business Suite Technology Codelevel Checker (ETCC)

Source: https://blogs.oracle.com/stevenchan/what-tools-do-you-use-to-patch-ebs-122-oracle_homes