A number on its own is trivia; a number against its past is management. So every headline measure carries its comparison family automatically — the family resemblance is called flux, short for fluctuation, and you will meet it on every KPI tile. For any measure and any period, the family is:
- the measure itself, for the period in view;
- the previous period — the same measure over the equivalent period before it (this fiscal period against the previous fiscal period, this quarter against the last);
- the variance — the simple difference between the two; and
- the variance % — that difference as a percentage of the previous period (reading 0 where the previous period was 0, rather than dividing by nothing);
- plus the trailing three periods — the measure summed over the current and two preceding periods, and its average — for smoothing a lumpy business into a trend.
Two rules keep flux honest. First, the comparison period is your fiscal period by default, matching how the business reports; a measure that is itself a percentage compares in points, not in percent-of-a-percent — margin moving from 20% to 23% is +3 points, and the tiles say so. Second, positions carry no flux: WIP value, open work orders, unbilled WIP, stock value, headcount. A position is a photograph of now, and last period's photograph is not a "previous value" of today's — comparing them would pretend a flow where there is only a state.