Usually very well known indicators, and they require only very simple arithmetic:
- totals (total sales, total profit, …)
- averages (average sales value)
- counts (count of orders per month)
- ratios (profit ratio = profit / sales)
- highest / lowest amounts (highest / lowest sales amount)
Small data we can very comfortably process in Excel, using extension called “Pivot tables”. This extension helps us with most commonly used KPIs.
Bigger data need some database. See my text about databases for data science.