If you combine all your monthly sheets onto a single one, I believe Pivots could give you more information than you have now. I'm positive it would be much faster.

You can Group Dates and have filters by department or by type or category much easier with a Pivot.

Look at
http://chandoo.org/wp/2009/11/17/gro...-pivot-tables/ or
http://fiveminutelessons.com/learn-m...el-pivot-table

You didn't really give us enough data to show what Pivots can do..