> ## Documentation Index
> Fetch the complete documentation index at: https://docs.meerietechnology.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Build or change a model with Claude

> Edit estimates, options and the diagram. Every accepted change becomes a new version.

Claude changes a model with one tool, `propose_model_update`. You need the **editor** role for the user you connected as.

> [!WARNING]
>
> Try this on a **copy** of your data first. Every accepted change is saved as a new version. Nothing is edited in place, and earlier runs keep pointing at the version that produced them, but they are marked out of date.

## What can change

* Inputs and their estimates
* Options and the decision framing
* Declared dependencies between estimates (correlations)
* The influence diagram: add inputs, calculations and modules, draw or remove arrows, set formulas and outcomes
* Objectives and risk attitude

Every formula is checked before it is accepted.

## Examples to ask

* "Change the adoption estimate to a lowest of 50%, most likely 70% and highest 85%, and say why." This is a three-point (bounded) estimate.
* "Add an input called support cost, uncertain, between $20k and $60k, and use it in the cost calculation."
* "Set the risk tolerance to 50,000 and rank options by certainty equivalent."
* "Generate a decision tree from the diagram using the three biggest events."

Claude includes a short **change note** with each update, which you can see in the version history.

## Correlations

Ask "How will the dependencies in this model be simulated?" and Claude uses `review_correlations`. It shows each pair's correlation, whether the whole set is consistent, and the nearest consistent values if it is not. To work out a correlation from data, ask it to use `calculate_correlation` with paired observations or a connected data source. See [Correlation](https://docs.meerietechnology.com/estimate/correlation.md).

## Check your work

After any change ask Claude to **validate the model** and **list what changed since the previous version**. Then open the decision in the browser. It is the same record.

> [!TIP]
>
> Be specific about shapes: say "likely range" (a 1 in 10 chance outside each end) or "hard limits" (nothing beyond them). They mean different things. See [Choosing how to describe an estimate](https://docs.meerietechnology.com/estimate/describe-estimates.md).

**Next:** [Run and compare simulations](https://docs.meerietechnology.com/mcp/run-simulations.md)


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