As per my assumption UPDSRVPGM doesn't require UPDPGM once you made any changes to any particular module attached to service program(having Binder language).
But it seems i am wrong. Everytime i make any changes to child module(containing PI of the procedure), along with UPDSRVPGM, i also need to execute UPDPGM to reflect those changes. Am i correct pls elaborate if no? If it require UPDPGM too, then i need to issue UPDPGM command to all those programs using this changed module which seems not good.