It's a good question...

Labor spending (in its own table, and database...) is key-entered.
Material spending comes from two sources, one key-entered (a small inventory
system), and an excel extract from mainframe-type sources (no SQL access).
Internal labor is key-entered into a mainframe-type app, then excel
downloaded.
Miscellaneous spending is extracted from SAP purchasing (again, excel).
Budgets are key-entered into a small Access app on this db.

To show composite spending, I develop (sub)queries that summarize the data
by category, then a final query  that shows all the summaries as columns, and
is exported to excel.

This works fine for the final report and to some extent for management
review. It does not help so much for detailed analysis, both at the
management level, and at the level of data validation.

Since much of the data entry is out of our control, descrepencies are
common, stupid, and result from lack of discipline, training, and automated
controls on systems that are being used in ways not contemplated by the IT
folks who bought or developed them. We ought to be using SAP for this work.
IT is focused on ongoing operations. We are responsible for renovations and
construction projects that cost millions, but can't get in the way of
production.

The issue I'm workin' on here is data validation. So you have a download
from SAP of all the POs written for miscellaneous expenses. I match it to the
application's internal table of such transactions (yes, I know we're
replicating the SAP system... I don't like it, but it's work, and the client
needs it....) Due to allocations in our system that vary (reasonably) from
those in SAP, I need to juxtapose the data. I did this on a form, and it
dramatically improved their productivity. Now, I'd like to do the same thing
on a report.

I've never done a "subreport", though I've done scores of "subforms". I
tried a subreport yesterday, but I struggle a little with it. I'll keep at
it.

From you, I was looking for strategy. How would you plan it out? Can I put
two subreports side-by-side and get decent-looking results, etc? How will
Access compensate for differing report depths, etc.

Thanks for reading my rant. I appreciate your questions!