Track accepted lots, escapes, on-time delivery, response time to corrective action, and severity.
A practical route
Define the denominator before publishing a percentage. Add a severity override so one major escape cannot hide behind a green average. Use a tiered response: monitor, request action, audit, or qualify an alternate source.
What good looks like
The process is visible at the point of work. The person doing the task knows the current requirement, the person approving it can see objective evidence, and the owner can tell whether the control worked. Keep the record small enough to complete in the moment: requirement, result, exception, owner, date, and next decision.
The failure mode to avoid
Do not solve a recurring process problem with a longer form alone. Watch one real job, find the handoff that breaks, and change the workflow or responsibility. Then sample the next few records to confirm the change stuck. The output should be a record someone else can verify. Use the supplier evaluation template. to keep that chain together.