Designing a functional test for a supplier sample

A functional test is useful only if another reviewer can repeat it. Define the intended use, setup, input conditions, duration or cycles, and pass criteria before the sample is tested. Product-specific safety tests may require an accredited or qualified laboratory.

Make the test repeatable

Record sample ID, equipment, operator, date, and environment where it can affect performance. State the expected output and what would count as failure. Capture observations such as noise, heat, response time, or leakage in units where possible. Keep photographs or raw files rather than a bare “works fine” note.

Handle a failure

Describe the failure mode and the conditions that produced it. Ask the supplier for a cause and corrective proposal, but retest the corrected revision against the same agreed method. Do not approve the original sample because the failure seems minor without checking its effect on the intended use and acceptance limits.

Worked repeatable test

For an illustrative valve sample V-2, agree to hold a specified pressure for five minutes and record any leakage using the project's test method. Enter V-2 and revision 3 in the sample review tool; put the actual pressure, duration, result, equipment ID, and file path in notes. Mark function “Deviation” if the agreed limit is exceeded. Common error: reporting “works well” after one informal trial without the conditions needed to reproduce it. Retest the corrected revision the same way.

Source context: ISO — ISO 9001 quality management systems supports this limited point: ISO 9001 specifies quality-management-system requirements, not a product-specific inspection result. The buyer procedure above is Suppliers Help editorial guidance. Source checked 2026-09-27.