Epics
When we conceive a new product idea, we start with the epics. Epics are very high level requirements. For example, while designing the web site for a bank some of the epics could be;
User management
Personal banking
Private banking
Corporate banking
Auto finance
Credit cards
Debit cards
Security
ATM and branch locator etc
Epics cannot be estimated. In order to estimate epics, the first step is to study the features associated with the epic. Once the features are known, then their stories can be developed.