# 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 %}

{% stepper %}
{% 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.
{% endstep %}

{% 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.
{% endstep %}

{% 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.
{% endstep %}
{% endstepper %}

***

## 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)


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://help.modelreef.io/syntax/drivers-syntax/operational-driver-fields.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.