Layers in uCMDB Service Model

Hi Experts Need your advise on the below query. we are building new service model in ucmdb. kindly confirm which layers is correct 1 Business 2 App 3Software 4Infra 5 Network or 1 Business 2 App 3Infra 4Software 5 Network we have confusion between Software and Infra.Kindly help on this. Regards, Pyneni