Metric Definition

A metric definition specifies what a reported quantity means and how it is calculated. It connects a business question with the counted unit, inclusion rules, scope, time treatment, and implementation. For a rate, the numerator and denominator also need explicit definitions.

Three correct counts need three names

In a fictional cohort, 70 orders are paid and unrefunded, 10 were paid then fully refunded, 15 await payment, and 5 were canceled unpaid. Created orders equal 100, ever-paid orders equal 80, and paid unrefunded orders equal 70 at the shared cutoff. These answer different questions.

A definition must state the cutoff and refund treatment, not merely name the source column. Partial refunds need an explicit rule; an unsupported state is not permission to discard an order silently.

Version meaning as well as code

Record the owner, examples, query version, and intended use. Test that the implementation matches the approved definition. A query can run successfully while answering a different question.

When meaning changes, identify affected consumers and decide whether historical periods will be restated. Keep enough version and data references to explain why two published values differ.

Reference: UK Government: Data Quality Framework.