Combining numbers across business units is not a charting problem

A request for a combined dashboard usually arrives with a clear picture in the asker's head. One screen, every unit, one total.

What is not visible from outside: each unit already has its own definitions, and those definitions were never written down because they never had to be compared.

Take the one that comes up most often, when a transaction counts. When the order arrives, when goods leave, or when payment is received. Three answers that all make sense in their own context, and all three produce a different number for the same period.

Combine them without agreeing first and the result looks tidy on screen and misleads in decisions. This is the most dangerous kind of error, because it does not look like one.

So we reverse the order of work. Agreement on definitions first, technical work second. That part is not ours alone to do, and it cannot be. We can only show where the definitions differ; the decision stays with the company.

The technical work that follows is the easy part.