Calculating repetative data & presenting it via a (Venn)diagram

Hi there,

I am trying to measure data flow through my department. For example we have
Queries we execute in my department and have been made recently aware that
other department are doing the same activities. (complete other story! )

I want to be able to present via a venn diagram (if possible) the overlap
of activites between the departments and indicate the waste.

Im not quite sure which application best suits this request, so looking for
ideas!

Thanks for the help
Cheers
Sar*