Hi,
if your source system was in place then all your standard data sources you will find at source system t code - RSA5 under related application component.
SCM have lot of other concepts. You need to be specific which part of SCM is needed for you.
When you got requirement then you didn't receive any specs?
please Seek your functional help.
SCM data sources will start name with 0SCM*.
you can check at source system, Table - ROOSOURCE.
Use OLTP source - 0SCM* and execute it. it may shows all scm data sources.
Even you can use SCM as application component(APPLNM - *SCM*) and find all the data sources of SCM.
Some scm data sources:
0SCM_FRE_ANA_STCKEXC_1
0SCM_FRE_ANA_OP_STAT_1
0SCM_FRE_ANA_OP_MCHG_1
0SCM_FRE_REPL_EXC_1
Eh &S Service(assumed as ESS)also part of SCM module.if you explore more about SCM you will get all other basic details of your requirement from your source team.
Thanks