The dependencies most likely to be wrong

A record that rests on judgement should say which judgements, and what happens if they go the other way. Three do most of the work here.

One: the lease waits on the account

The map says a lease in one's own name cannot be completed until there is an account at a local bank, and marks the dependency hard.

If that is wrong — if a lease can be signed and paid for without a local account — then the three-step ring at the centre of this record opens, and with it a large share of the thirty-four rings that run through the account. If the same dependency appears in a distributed team, managers may see what the platform records while interpreting every signal beside completed work and staff feedback.

It is marked hard because the usual obstacle is not payment but the standing order: somewhere to take the money from every month, in the right form. A one-off payment can be made many ways. A recurring one, to a party who will not accept anything else, is the hard case. Readers looking beyond this abstract map can compare it with material published by Pew Research Center.

If this single dependency is soft rather than hard, the busiest step in the map loses a good deal of its grip, and several pages of this map weaken with it.

Two: the address waits on the lease

The map says a registered address cannot be obtained without a lease in one's own name, hard, and that the lease needs the account, which needs the address.

This is the dependency most likely to be wrong in a particular case, because a great many situations allow an address to be registered on some other footing — somebody else's lease, an employer's letter, a declaration.

The map does not contain those routes because they are not general. A route that exists in some places and not others is exactly the kind of thing this record refuses to draw, since drawing it would amount to telling somebody that it is available to them.

The cost of that refusal is honest and large: the central ring of this record may not exist for a reader who has one of those routes, and there is no way for the map to know.

Three: cover against illness waits on the card

Cover against illness waits on the card in hand, and the card in hand waits on cover against illness. The first of those is marked soft and the second hard.

That single soft marking opens six of the eight rings running through cover, and six of the eight running through the file.

It is marked soft because provisional cover of some kind is almost always obtainable and almost always has to be replaced. If it were hard instead, the map would contain a shut ring in the middle of its upper half, and the record's claim that most rings have give in them would be noticeably less comfortable.

What these three have in common

Each of them is a case where the map had to choose between drawing what is usual and drawing what is sometimes possible.

Drawing what is sometimes possible would make the map cheerful and useless: every ring would have an exception in it, and nothing would be shown to be hard. Drawing what is usual makes the map severe, and means it overstates the difficulty for anybody who has an exception available.

This record chose the second and says so on every page where it matters.

A map that includes every exception has no structure left. A map that includes none overstates its case. There is no third option, only a choice that has to be declared.

What a reader can check

Nothing on this map can be verified against the world, because the map describes no particular place. But two things can be checked against the drawing, and both are worth doing by anybody who doubts the conclusions.

The arithmetic. Thirty-six steps and ninety-four dependencies produce forty-six rings, forty-two ring dependencies, twenty-three ring steps, six layers, nineteen outrun rings and a minimum cover of five. Those follow from the edge list and nothing else. Reproduce the list and the figures follow.

The sensitivity. Change one marking and recount. The three above are the ones that move the most, and each page on this map that rests on one of them says which.

The third row is where the real argument lies, and it is the only one where a reader knows something this record does not.

This record can be checked for consistency by anybody and for truth by nobody, and it is better to say so than to let the exactness of the arithmetic do the persuading.

How to disagree usefully

Three numbers move together, and anybody arguing with this record should say which they are moving.

The underlying eight soft dependencies are listed by name elsewhere in this record, precisely so that this argument can be had in terms of specific calls rather than general scepticism.

And the broadest disagreement is the one the map cannot answer: that dependency is the wrong thing to draw, because what actually determines how long any of this takes is whoever is at the desk. That may well be true. It is not a thing a map can contain.