Joining Factless Fact tables

I am new to BI/Warehousing but have been asked to develop a better reporting system for our software. I am designing a warehouse and seem to have a lot of factless fact tables. There are also many situations where these "fact" tables should be joined together.

One instance is Appointments with Episodes. I have appointments set up as a fact table with about 12 dimensions and have an Episode fact with about 15 dimension. Neither of these tables have any true "facts" other than a simple count. Appointments can have episodes attached, how to I link these and use them for reporting? Do I use a Degenerate Dimension or create an actual "Episode" key? Do I need to set up an entirely new fact table that is a combinaion of episodes and appointments?

Thanks in advance.

Stefanie

Joining to facts basically involves indiviual aggregate queries (summarized to the same grain) against each fact table with the results joined along common dimensions.

I would not suggest another fact table, but you may want to consider carrying an episode count on your appointments fact table.