What Is an Overlay?
An overlay is a user-defined adjustment to your forecast. Think of it as a "what-if" layer that sits on top of the model's baseline predictions without changing the underlying historical data.
Overlays let you express business judgment in quantitative form — for example, "revenue will grow 15% in Q3 due to a new product launch" or "we expect to hire 10 additional engineers in H2." Each overlay targets a specific Measure, applies a specific operation (Scale, Override, or Offset), and is scoped to a date range and optional dimensional filters.
Overlays are the primary way FP&A teams encode assumptions into Galdera:
- They are versioned and auditable
- They can be grouped into Scenarios for comparison
- They do not affect historical actuals — only forecast periods