Meaning
Formal procedures define the conditions under which a product may be tested a second time after an initial failure during certification. Reliable sample re-test protocols prevent manufacturers from simply repeating a test until a passing result is achieved by chance. These rules ensure that any second attempt is based on a genuine correction or an identified error in the test setup.
Root Analysis
Investigation into the cause of the failure must be completed before any additional testing is allowed. This process identifies whether the issue was a design flaw, a manufacturing defect or an error in the laboratory configuration. The findings must be documented and submitted to the certification body for review.
This documentation provides the justification for continuing the approval process after a negative result.
Batch Selection
Testing the same physical unit that failed is often forbidden unless a specific repair was made. Instead, the laboratory may require a new set of samples from a different production lot to ensure the pass is representative of the whole line.
Verification Cycle
Successful results from a re-test must be supported by evidence that the underlying issue is resolved. This often involves repeating not just the failed test but also related measurements that might be affected by the change.
