The IBMi is a very reliable system.  That does not mean that you can ignore it.  Have you thought about doing a systems analysis and health check ?  When was the last time you did a technology refresh ? Still on unsupported releases like V5R4 ?
For more details,  contact us at info@mapconsult.com
System Analysis and Health Check:

Work Management
DB2 Indexing
Startup & Shutdown
Backup and Recovery
OS Maintenance Levels
Exception Management
Incident Management
Operational Practices
Network Interfaces
Root Cause Analysis
End User Client Connectivity
Overall Health Assessment Report
Overall Risk Assessment Report

System Improvement:

Performance Tuning
Capacity Planning
DB2 Index Optimization
Security Remediation
Unattended Backup
OS Upgrades
Operational Automation
Single Sign On (Kerberos)
Secure Connectivity (SSL & SSH)
Password Synchronization