We're all well aware about SUM (Software Update Manager), the program that was made to make the life of BASIS consultants engaged in an upgrade or update project much easier.
SUM was created to be "THE ONE TOOL" regarding upgrades and updates of SAP systems, replacing the swarm of different programs that were used to perform the maintenance of different SAP system types.
There are two points that I think are important to be checked regarding SUM:
1 - What specific tools/programs were fully replaced by SUM
This topic is very important, as it can happen that someone uses an unsupported tool to perform maintenance tasks in the system, and some issue happens in the process that will not be corrected, since the tools are no longer supported.
- All JSPM versions are currently on "Limited Support" status, which means they will no longer receive any updates of fixes.
- SOLMANUP is no longer supported.
I suggest to check the PDF attached to SAP note 1589311 - Replacements of outdated tools via SL Toolset for an official documentation from SAP regarding this point.
2 - Is there some scenario where SUM cannot not be used?
The answer to this question is on the PDF attached to SAP note 1843776 - Central Note - Software Update Manager 1.0 SP09, SUM_SP09_paths.pdf. There we'll find that almost all upgrades to the latest release of SAP systems are fully supported by SUM from any source release (as of Netweaver 2004).
The problem lies on the intermediate upgrades, like going from an ERP 4.6c to ECC 6.04. Such cases should be checked in the path list PDF in note 1790828. Also, some dual-stack configurations are not accepted by some version targets, which would demmand a dual-stack split.
If the upgrade path you are trying to follow is not listed, then you must check the specific upgrade guide to the target release, available at http://service.sap.com/instguides
So, do you have any specific question about SUM usage and replaced tools?
Let's hear in the comments 