No worries. This is a 14-sheet workbook with 8 source reports all in different tabs (those source reports will be periodically re-imported), and a set of "analysis" sheets that cross-reference data among the source files (e.g look column A in source file 1, return column D....take that data, look it up in source file 2, return column E...if E is x, then look it up in source file 3 and return col G, but if E is y, then look it up in source file 4 and return col H....and so forth....). The underlying structure of the data is, of course, the root problem here, as is the fact that we're doing this in Excel versus a proper Business Analytics tool, but I can't change either of those variables. If I could come up with an easy way to demonstrate with a sample file, I'd try to load it here, but this isn't about getting a formula to work ... it's about structuring the whole thing to optimize performance ... oh, yea, and to be able to hand this whole workboook off to less sophisticated users who, with some basic instruction, should be able to generate the output each successive time the source data is updated .... ugh. In essence, I'm building a program here, but one that doesn't require Excel to take 22 minutes to calculate...