The monthly business review

Every month, leadership sits down with one table: how much we sold, to how many people, how much came back, and how the site converted, next to last month and the same month last year. That table is the monthly business review, the MBR, and building it is one of the most common jobs an analyst has. It looks routine. It goes wrong when the month is not finished, when a definition changes quietly, or when the headline picks the flattering comparison.

This case is the whole job, the way you would do it at work:

1. Frame the review: which month, which KPIs with which definitions, compared with what, and for whom.
2. Check the data: make sure the month you report has settled, with no orders still pending.
3. Analyse in SQL, pandas or Excel, whichever you prefer: the KPI table for three months, then the drill-down that explains the biggest mover.
4. Recommend: pick the headline you would put at the top of the review, with the caveats.

The case opens when you finish any one of the chapters it builds on: SQL chapter 7, pandas chapter 10 or Excel chapter 12. It uses CTEs and conditional counts (or groupby on a month column in pandas, or XLOOKUP and INDEX/MATCH on a prepared monthly sheet in Excel).