Thanks for your answer:
- we did it with JSPM, and it seems to work for this ADD-ON installation.
I also know about that sapnote and there are some more sapnotes:
http://service.sap.com/sap/support/notes/1589311 and attachement .pdf
http://service.sap.com/sap/support/notes/1147119
but my question is not answered yet:
is it possible to run a SPS-Update (in NW-7.31 Doublestack-PI-System)
and at the same time installation of additional ADD-ONs (e.g. SFTP) in one SUM-run ?