A drilling programme is often the largest single cost in exploration. Its real output is not metres drilled but reliable data - and reliability has to be demonstrated.
A robust QA/QC programme inserts certified reference materials to test laboratory accuracy, blanks to detect contamination, and field, coarse and pulp duplicates to measure precision at each stage of sample preparation. Results are tracked on control charts so that failures are identified and resolved while the rig is still on site.
Good practice also covers what happens before the laboratory: core recovery measurement, consistent logging, core photography, secure chain-of-custody and density determinations on representative samples.
When QA/QC is weak, resource estimates are downgraded, confidence categories are limited and re-drilling may be required. When it is strong, the same data can support higher resource classification, faster studies and smoother technical due diligence.