monitoring control for privileged/administrator activities in Oracle EBS R12.2

We have an audit requirement to establish a formal monitoring control for privileged/administrator activities in Oracle EBS R12.2.15 We need to monitor activities such as privileged/generic account access, responsibility/access changes, security/configuration changes, critical application changes, and changes to auditing settings.

What is Oracle's recommended approach for implementing this? Should this be accomplished using Sign-On Audit, EBS AuditTrail, database auditing, or a combination of these features? We are particularly interested in Oracle supported reports/scripts or best practices that can be used for a weekly privileged activity and configuration-change review.