To plan and simulate maintenance transactions, SAP Support Portal offers the maintenance planner. It creates a high-level system landscape plan, based on your landscape information, including an impact analysis:
Overview of system landscape, including system dependencies, before planning a change.
Understand SAP-specific semantics of structuring systems.
Easily simulate product changes in your landscape to quickly understand the impact.
Create a maintenance transaction and a download basket with stack XMLs, which can be consumed by Software Update Manager (SUM).
You can start the maintenance planner with https://apps.support.sap.com/sap/support/mp.
for more information, see http://help.sap.com/maintenanceplanner.