How to audit CIP (Clean-in-Place) cleaning records in food processing?

CIP records in food processing may look like just a few items—temperature, time, concentration, and flow rate—but if you really want to investigate issues on the floor, checking if the boxes are ticked isn't enough. I've seen records that looked perfect, only to find residue in dead zones when the piping was dismantled. It turned out that the valve switching for that section was based on…