How to model comparible store sales for retail data

I am looking for suggestions for how to model comp store sales (vs. non-comp) in a retail data warehouse. One of the requirements is to be able to take any store status of comp (comp, just opened, temporary close, etc) at a point in time and use that value as the basis for comparison for this year vs. last year.

Any suggestions would be much appreciated.

If you collect sales information at its lowest level, doing comparative sales is a simple query problem, not a design problem. Building aggregates will help performance.

thanks for your reply. yes, we are collecting at the lowest level, but since comp status can change daily, i'm interested in a typical data model to handle reporting. how have you seen it modeled effectively?