Cannot find any tcodes while creating the Function id in for risk analysis

Hi Friends,

the issues was appeared while I was practising the Risk analysis,

I went access maintainance , then to fuctions , I  had given the fuction name , business process , analytical scope

then when I tried to add the t-code , I couldn;t see any t-code to add to the function

is there any pre-requesties to do before this ?

Thanks and Reagrds,

Raghu