I have worked under number of "point" systems which allows you to document employee attendance. This is a safety net to prevent someone saying they got fired for missing X amount of time while someone else missed twice as much and is still working.
Last one, many years ago, was 7 frequencies, 50 hours. Example: Taking a day off sick was one frequency and 8 hours. Taking 3 consecutive days off was one frequency and twenty-four hours. Leaving two hours early was one frequency and 2 hours.
Frequencies and hours came off a year after earning them.
Reaching 32 hours OR 4 frequencies was verbal warning. 40 hours OR 5 frequencies was written warning. 48 hours OR 6 frequencies was 3 days off without pay. 50 hours OR 6 frequencies was termination.
Seemed a little strict, but it worked.
All the Best,