Guides

Nine stages, from naming the question to keeping the model alive, in order.

Read them in order the first time. Each one ends with the next. They are written for the person who has been asked to get a model made and is not a modeller; the technical detail is one layer down, in the engines and data entries they link to. Not sure you need a model at all? So you want to make a digital twin? asks five questions first.

Name the question guide draft

Write down the one question the model must answer, who will act on the answer, and what they will do differently.
Talk to the people affected guide draft

Before the model, talk to the people the decision touches. They hold the data you do not have and the questions you did not think of.
Find the data guide draft

Every model of a place starts from the same few layers. Find them, check them, and write down where they came from and how old they are.
Choose the kind of model guide draft

There are a handful of kinds of model, and each answers a different shape of question. Picking the kind is most of the choice; the product comes after.
Build the smallest version guide draft

One place, one scenario, one output, made quickly and shown to the people who asked. Then grow it only where they push.
Check it against what happened guide draft

Run the model on a past event and compare it with what actually happened, before anyone decides on it.
Protect people's privacy guide draft

Models of places are models of the people in them. Decide what you will not collect, aggregate the rest, and say in public what you did.
Put it in front of its users guide draft

Make the output fit the meeting, the screen and the person who will use it, then watch them use it.
Keep it alive guide draft

Decide whether the model should live on after the decision. If it does, it needs an owner, a data feed, a check and a budget, in writing.