Why individual results hide the trend
Any single inspection can be explained. The building was busy, an area was occupied, the cleaner was covering, it was the night after a public holiday. Each explanation is reasonable and each one is accepted. What is lost is that the same reasonable explanations have been offered four visits running and the underlying condition has been declining throughout that period. The trend is the finding; the individual visits are only the data points.
Comparing results is what surfaces it, and it does not require an elaborate scoring system. A supervisor who records the same items each visit and looks at the sequence will see a trend immediately. The important discipline is looking backwards at the previous records before writing the current one, which takes two minutes and is skipped more often than it should be. Reviewing the last three records before writing the fourth is the entire discipline.
