Linking Drivers to Variables

This article explains how to link drivers to variables in Model Reef.

You will learn:

• The different ways drivers can feed variables.

• How to configure links in presets and formulas.

• How changes in drivers propagate to financial outputs.

Drivers only affect financial statements when they are linked to variables.

1

Linking via presets

Many variable presets allow you to link drivers directly, for example:

• Selecting a volume driver to determine units sold.

• Selecting a price driver to determine revenue per unit.

• Selecting an inflation driver to escalate costs over time.

In these cases you choose the driver from a picker within the preset configuration. The preset then reads the driver values each period.

2

Linking via formulas

You can also link drivers using explicit formulas, for example:

• Revenue variable = Units driver × Price driver

• Cost variable = Base cost driver × Modifier driver

Here you enter the relationship in the Formula modal, and the variable's time series is entirely determined by the formula.

3

Linking via Data Library entries

Sometimes a Data Library entry encapsulates both:

• An imported series.

• Driver based forecasts.

Variables that reference the entry implicitly link to whatever driver logic is defined there. Editing the entry updates all linked variables at once.

4

Propagation of driver changes

When you change a driver that is linked to variables:

• The driver time series updates.

• All variables that use that driver recalculate.

• P&L, Balance Sheet, Cashflow and Cash Waterfall update in the active scenario.

• Dashboards, charts and valuation outputs update automatically.

This is the core advantage of driver based modelling: a single assumption change can update many parts of the model coherently.

5

Traceability

To understand how a variable is driven:

• Open the Variable Editor.

• Review preset and formula sections for driver references.

• Use notes to document key driver relationships.

This makes it easier for reviewers to see which assumptions are central and where they live.

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Related articles

• Overriding Variables

• Selecting Drivers in Sidebar

• COGS Variables: what is, rules, what it affects

• Build a Stress Test / Downside Case