KPI definition

Turn a fuzzy goal into measurable success. Be ruthless about picking few, good metrics over many vanity ones.

Method:

1. Name the outcome — the real behavior change or business result you want (not an output like "ship feature X").
2. Pick the North Star for this work — the single metric that best captures the value delivered to users. Define it precisely (numerator, denominator, time window, population).
3. Add input metrics — 1–3 leading indicators you can move week to week that should drive the North Star. These are what the team actually steers on.
4. Set guardrails — metrics that must NOT get worse (latency, churn, support tickets, cost). A win that breaks a guardrail isn't a win.
5. Baseline & target — current value, the target, and the timeframe. State the assumption behind the target.
6. Instrumentation — what events/data are needed to measure this, and whether they exist yet. Flag gaps as prove-stage work.

Output a small table:

Sanity checks:

• Could someone game this metric without helping users? If yes, fix it or pair it with a guardrail.
• Is it measurable now, or is building the measurement itself a task to log?

Record the chosen KPIs as a note on the ledger item (and in the PRD's metrics section).