What to Start Doing.

• Activate Statistics (ST03N) if it is not Active.
• Taking an Inventory:
  • Identify all Z Code.  Use ST03N Statistics.  Link here  What is Used, What is Obsolete, What needs Enhancement.
  • Identify all Interfaces, what are the End Points, Where is the Test Data.
  • Number of Users in the System (any Users that do NOT have Expiration Dates but have Departed).
• Get an S/4 Readiness Check Completed.  This takes up to Eight (8) Weeks to get all the OSS Notes (For Older ECC Systems).
• Install ABAP Custom Code Check
  • Good Blog 
  • OSS Note
• Determine Cloud Strategy (Additional Entries Coming).