4C is what I use for analyzing complaints that are due my behaviour, errors or lack in knowledge.
C1: Complaint / “You forgot what I’ve ordered”
C2: Cause / “I was busy with another guest while confirming his order”
C3: Consequence / The guest had to wait a long time
C4: Correction / Going to the kitchen and request the plate with urgence
C4: aCtion / Going to look for a notepad so I write the orders down
Very easy to remember and use 😀