# Metric definition card

One card per metric. Keep it on one page. The owner decides when two reports disagree.

| Field | Entry |
| --- | --- |
| Name | |
| Plain-language definition | One or two sentences a non-analyst would agree with. |
| Formula | The calculation, written so a second person could rebuild it. |
| Owner | A named person, and a backup. |
| Source of record | The system and table or view the number comes from. |
| Grain | One row per what? (for example, per customer per day) |
| Known exclusions | What is deliberately left out, and why. |
| Where the calculation lives | The one shared model, data source or measure that holds it. |
| Last reviewed | Date, and who reviewed it. |

## Worked example (illustration only, not a recommended definition)

| Field | Entry |
| --- | --- |
| Name | Active customers |
| Plain-language definition | The number of distinct customers who placed at least one completed order in the 90 days up to and including the reporting date. |
| Formula | COUNT DISTINCT customer_id WHERE order_status = 'Completed' AND order_date is between (reporting_date - 89 days) and reporting_date |
| Owner | Example Head of Customer Operations. Backup: Example BI Lead. |
| Source of record | EXAMPLE orders table in the sales warehouse (one row per order line). |
| Grain | One value per reporting date. |
| Known exclusions | Internal test accounts. Orders later fully refunded. Wholesale customers (reported separately). |
| Where the calculation lives | The EXAMPLE shared sales model, measure "Active Customers". Reports must not recalculate it. |
| Last reviewed | 2026-09-30 by Example BI Lead. |