Averaged over
The reference period, the rolling window, and why the figure moves when nothing changed.
The Week That Drops Off
A rolling average moves in two directions at once, and the week leaving the window matters as much as the week being added. Nobody is watching that end.
What a Reference Period Is
An averaged limit is two numbers, not one, and the second number does more work than the first. Most people working under one have never been told it exists.
Rolling or Fixed: Telling Which You Have
The two shapes produce opposite management behaviour, and a surprising number of organisations cannot say which one they are running.
Who Actually Computes It
The rolling average is a calculation somebody has to perform, and on most sites the honest answer to who performs it is nobody.
Leave, Sickness and the Denominator
What happens to a week somebody was absent is a technical question with a large effect on the figure, and getting it wrong in the generous direction hides real load.
Starters, Leavers and Short Service
Somebody who has been here five weeks has no seventeen-week history, and what the system does with the missing twelve decides whether they can be rostered at all.
Where the Number Should Live
A compliance figure in a monthly report changes nothing. The same figure beside a name in the rostering screen changes the rota, which is the point.
How Wrong the Figure Usually Is
Every organisation that produces an average produces one that is too low, and the amount it is too low by is estimable in a day.