Hoo boy...you know how when you start cleaning out the closet and you end up cleaning the garage, the bathroom, and even the refrigerator? That kind of happened here.

I don't know if you'll be able to use any of this, but here it is. I am kind of a stickler for proper design owing to my days doing database development. Setting up a workbook properly can help immensely down the line.

Some notes, pointers, etc...
* Keep tab names simple. Adding dashes or even spaces can make the equations that refer to the tabs ugly and thus less understandable. Thus I renamed your last two tabs Metrics and Performance without any loss of context in my opinion.
* Each large table of data should have its own sheet and the sheet should only have that table. Thus I moved the stats you had from Performance to Dashboard.
* Use the Format As Table button on your tables, especially any that have data that will be used in equations elsewhere. Also, use the [Formula]Name Manager to rename the table logically. I did so with the data on the Performance tab and renamed the table Performance.
* Keep the table field names (the column headers) simple. Like the Tabs, keep any superfluous characters to a minimum. By doing so, an equation might look for instance like =SUM(Performance[Barclay]) rather than =SUM('Performance-Data'!G:G) with obvious advantages in creating, editing, and debugging the equations. It is even more obvious as equations become more complex.

Having done that, I modified all the equations I could on your Tear tab. For instance, rather than tediously adding individual cells, your calculation for 2013 Barclay becomes....

=SUMPRODUCT((Performance[Month]>=J16)*(Performance[Month]<J16+365)*(Performance[Barclay]))

Much more could be done but I'm afraid I've done too much for you to digest already. But if you think this is valuable and you would like further assistance in making this a truly robust sheet, I will help you as much as I can. However, we should probably take it offline and work by email.

Attached Files

Performance SummaryFIXed.xlsx (54.5 KB, 11 views)