# Assumptions Wizard

## Setup

<figure><img src="https://2847533834-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FVy65sax6FVoNo2UTlJ0x%2Fuploads%2FBzBoVW7JFERMzBOG5RGQ%2Fimage.png?alt=media&#x26;token=6650e519-410b-4fb3-8851-e9bcd94bb2e5" alt=""><figcaption><p>Setup page of the Assumptions wizard</p></figcaption></figure>

### Name

Enter a name for your Assumption. There are no restrictions to how you name your Assumptions, as long as the name isn't blank.

{% hint style="info" %}
Bear in mind that if you will be generating Excel from your Model, Assumption names will be written in the spreadsheet, meaning you should avoid choosing a name that Excel will interpret as a formula, otherwise you will run into problems.
{% endhint %}

### Value Source

Assumptions can take their value from 3 sources:

<table><thead><tr><th width="237">Value source</th><th>Description</th></tr></thead><tbody><tr><td><code>Local Input</code></td><td>Manually entered values which are stored within the Model, and cannot be shared between Models</td></tr><tr><td><code>External Data</code></td><td>Values which are stored in a separate <a href="../data"><strong>Data</strong> </a>application; These values can be used by multiple Models</td></tr><tr><td><code>Link to Plug-In</code></td><td>Values stored in an Excel spreadsheet, which are added to the Model when generating Excel</td></tr></tbody></table>

The Assumptions wizard will update with the relevant steps according to the option chosen here. Instructions for entering data for each type of source can be found at the following locations:

* [**Local Input**](https://help.taglo.io/assumptions/assumptions-wizard/assumption-values-step)
* [**External Data**](https://help.taglo.io/assumptions/assumptions-wizard/linking-to-external-data)
* [**Link to Plug-In**](https://help.taglo.io/assumptions/assumptions-wizard/linking-to-excel-inserts)

{% hint style="info" %}
An Assumption can use different sources for each [**Scenario**](#scenarios) in the Model. e.g. you might link to External Data for the Base Scenario, and then enter Local Input values for alternative Scenarios
{% endhint %}

### Dimensions

Choose any [**Dimensions**](#dimensions) that you want to apply to your Assumptions.

{% hint style="info" %}
When editing multiple existing Assumptions, any Dimensions will be automatically detected and cannot be changed
{% endhint %}

### Number Format

Choose the [**Number Format**](#number-format) to apply to your Assumptions.

### Scenarios

You can enter values for Assumptions for multiple [**Scenarios**](#scenarios) simultaneously. By default, the wizard will prompt you to enter values for the `Base` Scenario only, but you can select multiple Scenarios here, in which case you will need to enter values for all selected Scenarios.

{% hint style="warning" %}
For [**External Data**](https://help.taglo.io/assumptions/assumptions-wizard/linking-to-external-data), you can only select values for one Scenario at a time. If you want to use External Data for multiple Scenarios for the same Assumption, you will need to select Data for each Scenario separately.
{% endhint %}

### Data Type

Choose the [**Data Type**](#data-type) for your Assumptions.

## Unit

You will need to enter a [**Unit**](#unit) for your Assumptions.

[**See here**](https://help.taglo.io/units/defining-a-unit) for more details on how to use the Unit step of the wizard.