Most small business forecasts start as a list of totals typed into a spreadsheet, such as next year’s revenue, rent, and wages. When something changes, someone retypes the totals. A driver-based forecast instead calculates each line from the activity that causes it, so a change in one assumption flows through everything that depends on it.
What a driver is
A driver is an operational quantity that explains a financial line. Common examples:
| Business | Line | Driver |
|---|---|---|
| Contractor | Revenue | Jobs × average contract value, by start month |
| Farm | Input costs | Acres planted × cost per acre, by crop |
| Association | Dues revenue | Members by type × dues rate × retention |
| Professional firm | Revenue | Billable hours × rate × utilization |
| Any business | Wages | Headcount × loaded cost, by start date |
Choose few, meaningful drivers
The temptation is to model everything. Resist it. Pick the drivers that explain most of the movement in your results, usually volume, price, and headcount, and use simpler methods elsewhere:
- Run rate for stable costs such as software subscriptions.
- Growth rate for lines that move with general activity.
- Monthly values for known, irregular items such as an annual insurance premium.
- Percent of revenue for costs that genuinely scale with sales, such as card processing fees.
Every driver you add is an assumption someone has to maintain. Five good drivers beat fifty fragile ones.
Make assumptions visible
The point of drivers is that people can discuss them. “We expect 8 percent fewer acres of corn and a lower price” is a conversation management can have. “Revenue cell C14 is 1.2 million” is not. Put the driver values where everyone can see them, document where they came from, and date them.
Test with scenarios
Once a forecast is driver-based, scenarios become easy. Lower the price driver to test a weak market, push the start month of a big job to test a delay, or change retention to test a soft renewal season. Each change flows through revenue, costs, and, with timing inputs, cash.
Keep actuals and assumptions distinct
As the year progresses, closed months become actuals and the forecast continues from the drivers. Do not let the two blur. A good model makes it obvious which months are recorded results and which are projections, and it flags any driver that is missing rather than assuming zero.
PursuitBid supports run-rate, growth, monthly series, and volume-and-price revenue drivers, along with headcount-based costs, with the inputs visible beside the numbers they produce.
Written by the Syntonyl team. This article is general information, not legal, tax, or financial advice.