LADEINDEX
How the index calculates
It does not calculate yet — the time series is missing. What follows is the method it is committed to. It is fixed in advance, so that nobody later has to ask whether the rules were invented to fit the result.
The underlying problem
A charging point with twelve charging sessions and no failures is not a hundred percent reliable. It is unknown. Putting such values into a ranking puts the charging points with the least data at the top.
The method therefore pulls every value towards the fleet mean, and the more so the fewer observations it rests on. An operator with a thousand charging points moves far from the middle, one with three barely moves at all.
How quickly the past fades
A failure from two years ago says less about today than one from last week. How much less is not estimated but measured: the method determines from the data itself after how many months the informative value falls by half.
That half-life gives every figure its expiry date. A value that holds today visibly carries how long it holds — and after that it is no longer a value but a memory.
When we say nothing
Before every publication there is a counter-test: the assignment between charging points and their failures is shuffled at random and the method applied again. If the result on the shuffled data looks as good as on the real data, then the method is measuring noise.
In that case there is no figure. Not a cautious one, not one with an asterisk — “not assessable” is a valid answer, and often the most honest one.
Reproducible
Every published figure carries three things: the state of the data, the version of the method, and the checksum of the code that produced it. With those, any figure can be reproduced from the archived raw data.
If a recalculation differs, that is our mistake — and it is published as a dated correction, not quietly fixed.
Before an operator is named
No operator appears by name in an analysis without having been informed beforehand and given the opportunity to respond. That response is published verbatim if the operator wishes.