Referee

Pick two departments. The referee walks from one number to the other, step by step, and every step links to its rows. Everything is computed in SQL; nothing is estimated.

Marketing counts 1'102 leads created in September 2026. Operations counts 459 appointments. Both are right; they count different things. Step by step:

  • โˆ’429 leads have no appointment yet
  • โˆ’220 leads have their appointment in a later month
  • โˆ’100 leads had their appointment cancelled or missed (no-show)
  • +106 appointments are for leads created in an earlier month

= 459 appointments (Operations).

Step What Leads Rows
Start Marketing: leads created 1'102
minus Leads with no appointment yet 429

Show rows

minus Leads with their appointment in a later month 220

Show rows

minus Appointment cancelled or no-show 100

Show rows

plus Appointments for leads created in an earlier month 106

Show rows

End Operations: appointments 459