Dashbox

Chapter 5

It crosses a line you set

The colour asks whether a number moved. Sometimes the question is a different one: has it crossed a line I care about?

A balance that falls to a new levelA second example: a balance at 300 falls over a week to 60 and stays there, while its orange 7-day normal catches up. A dashed line marks a low trigger at 100. Three rows of squares underneath show each day: the colour row is rose while the balance falls and empty once the 7-day normal has caught up; the trigger row is amber from the day the balance passes 100; the card row shows amber from that day on.low 100normalcolourtriggercard
Another example: a balance, higher is better, with a low line at 100. The colour row goes empty once the normal has caught up with the new level; the line does not move, so the card stays amber.

The colour asks: has this number moved, compared with its own normal? It needs no setting beyond the direction, and it follows the normal as the normal changes.

A trigger asks: has it crossed a line I care about? It is your own fixed numbers on the card - a low line and a critical line, either below or above - judged on the headline value. Past the low line the card turns amber, past the critical line red.

Both are there because they catch different things. A balance that drops to a new level and stays there is rose while it falls. A week later its 7-day normal has caught up, yesterday is no longer below both averages, and the colour goes. The balance is still low. A line at 100 does not follow the normal, so it still says so.

And a number can leave its normal without coming anywhere near a line you would set.

When several things are true at once, the card shows one state, the most important: error, critical, low, stale, then bad, then good. A problem with the data comes before what the data says.

In the example month

An example, not real data.

Day 22
A release breaks the sign-up form. 9: below the low line of 12, and the card turns amber.
Day 23
4: below the critical line of 6. Red.
Day 24
The form is fixed during the day. 19: above both lines again, so no amber or red. Still rose: 19 is below both averages (19.6 and 22.7).