Solution : https://service.sap.com/sap/support/notes/1171916 (SAP Service marketplace login required)
Key words :
sap reference img -> supplier relationship management -> srm server -> master data -> define external web services, open standard call structuree, srm spro customization, improve system performance, correction instruction attached, srm reason, srm codebase, spro customization, prerequisites correction, transaction spro