# What are Models?

Models are used to Forecast your rows for a given date range. You can apply as many Models per Row as you want, as long as they are assigned to different periods.

Each Model will be automatically assigned a color, which will used to highlight the Forecast months the model is calculating. In the above example, 2 Models are assigned to a Row:

`GROW 4% PM`

- assigned to dates`Apr 2020 - Jun 2020`

`GROW 8% PM`

- assigned to dates`Jul 2020 - Dec 2020`

You can see in the Forecasts to the right that the` Mar 2020`

value is being increased by 4% each month until` Jul 2020`

where it starts increasing by 8% each month. The corresponding Forecast values are also color coded to attribute the model used to calculate the values.

## Adding a Model

To add a Model to a Row, start by clicking in the Model Cell for the row, then clicking the` +`

button.

Next select the type of Model you wish to add from the menu that appears. See "**Model Types**" below for more a more detailed explanation of each model type.

Then enter the required information for the Model Type that was selected. Each model will have the following fields in common:

**Name**- Use the model name as a way to clearly identify your assumption. Good model names are descriptive and specific such as`"growth 3%am"`

or`"constant gross margin"`

**Start Date**- The first Forecast month to apply the model. Defaults to the current`Project Start Date`

if no models are assigned to the row, or the next unassigned month if there are already existing Models assigned to the row.**End Date**- The last Forecast month to apply the model. Defaults to the current`Project End Date`

**Interval**- The applicable months in the date range beginning with Start Month. Defaults to a value of 1

When completed, click the` Save`

button to assign the Model to a Row.

## Updating a Model

To edit an existing Model, simply click on the Model pill in the required Row to see the settings for that particular Model. Once required changes are made, click the` Save`

button to update a Model. Its applicable Forecast values will then be immediately recalculated.

## Removing a Model

To remove a Model from a row, click the Model pill as if you were going to update the Model. In the pop-up menu, click the` Delete`

icon and the Model will be removed from the Row and its Forecasts will be updated.

## Interfering Models

Two Models assigned to the same row are not able to have their date ranges overlap unless they have different interval values. If upon saving a models date ranges will overlap, you will be given an error similar to below which will inform you of the conflicting model and its dates.

Models can have the same date range if their intervals cause them to apply to different months. For example, in the image below both` GROW 4% PM`

and` GROW 8% PM`

have an overlapping range, but a different *start month* and *interval* to ensure they don't overlap.

`GROW 4% PM`

- applies to`4/2020 - 12/2020`

with interval of`1`

`GROW 8% PM`

- applies to`5/2020 - 12/2020`

with an interval of`1`

## Model Types

Models can be created with a variety of types, which are all based on the functions above, but can speed up the process of creating your models.

**Custom Formula **

Uses the formula builder interface, so you can type functions as in formulas.

**Growth**

Returns a result based on a % growth of the previous period. If you select growth per year, the % is adjusted as` (1 + growth) ^ (1/12) - 1`

**Ratio**

Returns the value that maintains the ratio of the assigned row to another selected row, based on the average of a certain number of periods.

**Constant**

Repeats a value from the past, you can use it for all constant rows or for seasonal rows, which repeat every certain number of months or years.

**Series**

Allows entry of manual values for a selected range of months.

**Moving Average**

Returns the moving average of a number of periods.