accounts with many locations

accounts with many locations

what are best practices for managing Accounts with many locations, e.g. franchises?   Some customers are billed at headquarters and others are billed individually.  
- the Account Parent field  supports the Parent Child Hierarchical Relationship.
What is the best way to  generate a drill down report of Account and their locations.

Some users I noticed created a Custom Module, e.g. establishments.   Is there a good business case for creating duplicate data  and structures  which could complicate Creator functionality. 
 
Thank You for your input.