How to get a single source of truth for finance

A single source of truth for finance is one agreed definition of each metric, used by every report, model and tool. It is rarely one database. Many teams get there in four stages: scattered spreadsheets, a central data store, shared definitions, and governed definitions with owners. The jump that matters most is from storing data in one place to agreeing what it means.

Teams often assume a warehouse or a new ERP will give them a single source of truth. It gives them a single place to look. The numbers still disagree if each report defines them its own way.

The four stages

Each stage below shows what it looks like day to day and what moves a team to the next one.

1. Scattered. Each team keeps its own spreadsheets and exports. To move forward, agree which systems are the sources.
2. Centralized storage. Data sits in a warehouse or lake, but each report defines metrics its own way. To move forward, write shared definitions for key metrics.
3. Shared definitions. Key metrics are defined once and reused. To move forward, assign owners and an approval process.
4. Governed. Definitions have owners, history and lineage, and every tool reads them. To stay here, keep definitions current as the business changes.

How to tell where you are

1. Count the versions. Ask three teams for last quarter's revenue. If you get three numbers, you're at stage 1 or 2.
2. Look for the definition. Ask where the definition of a key metric is written down. If the answer is "in the SQL" or "in Sam's head," you're not at stage 3 yet.
3. Ask who approved it. If nobody can say who approved the current definition, you're not at stage 4.

How to move forward

1. Pick the ten or so metrics leadership uses most.
2. Write a plain definition for each, with its source and calculation.
3. Name one owner per metric.
4. Point every report and tool at those definitions instead of rebuilding them.
5. Review definitions when systems, products or the business change.

How Preql helps

Preql maps metric definitions across your existing systems and keeps them with their owners and approval history. The source of truth becomes the approved definition, wherever the data lives.

FAQ

Do we need a data warehouse first?

It helps, but definitions can be agreed and mapped across systems before a warehouse project finishes.

How long does it take?

Defining the first ten metrics is usually the quick part, especially with owners named up front. The longer work is getting every report to use them.