> For the complete documentation index, see [llms.txt](https://help.modelreef.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.modelreef.io/syntax/drivers-syntax/operational-driver-fields.md).

# Operational Driver Fields

This article explains **Operational Driver fields** in Model Reef.

You will learn:

* What operational drivers represent.
* Which fields matter most for operational drivers.
* How to set up unit and volume based driver series.

{% hint style="info" %}
Operational drivers are quantity- or activity-based inputs that underpin revenue and cost logic.
{% endhint %}

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{% step %}

### Examples of operational drivers

Examples of operational drivers include:

* Units sold per period.
* Active subscribers.
* Store traffic or visits.
* Headcount by team or role.
* Hours worked.
* Production volumes.

These series are often combined with prices or rates to generate revenue or costs.
{% endstep %}

{% step %}

### Key fields for operational drivers

When editing an operational driver you will see fields such as:

* **Name**\
  For example `Units - Product A` or `Headcount - Engineers`.
* **Type**\
  Set to Operational driver.
* **Units**\
  Units, people, hours or other quantity measures.
* **Time series grid**\
  Quantity per period, editable manually or via imports or presets.
* **Notes and tags**\
  To explain the origin, meaning and ownership of the driver.

These fields are edited in the Driver Editor or Data Library where applicable.
{% endstep %}

{% step %}

### Shaping operational driver series

You can shape operational drivers by:

* Typing volumes directly in the grid.
* Applying growth patterns (for example percentage growth each period).
* Using seasonality to reflect busy and quiet periods.
* Importing operational history and extending forward.

Often, operational drivers are the first layer in a bottom up model.
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{% step %}

### Using operational drivers in formulas

Operational drivers are commonly used in formulas such as:

* `Revenue = Units driver × Price driver`
* `Staff cost = Headcount driver × Salary driver`
* `Capacity utilisation = Actual units ÷ Capacity driver`

They provide the quantity side of most economic relationships in the model.
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{% step %}

### Scenario specific operational drivers

Operational driver series can differ by scenario model:

* You might have more aggressive volume ramps in an upside scenario.
* Or more conservative headcount growth in a downside scenario.

Adjusting operational drivers is often the cleanest way to explore different futures for the business.
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***

## Related articles

* [How Input Fields Work](/syntax/how-input-fields-work.md)
* [Data Library Viewer](/syntax/understanding-the-interface/data-library-viewer.md)
* [Driver Scenario Interactions](/help/drivers-variables-and-timing/driver-scenario-interactions.md)
* [Build a Rolling Forecast](/how-tos/scenarios-and-planning/build-a-rolling-forecast.md)