Check Whether PCB Inspectors Apply the Same Acceptance Decision

Two inspectors can use the same written criterion and still make different decisions on the same board feature. Before treating an inspection disagreement as a supplier quality difference, evaluate the consistency of the inspection method itself. Preserve independent judgments so that the study measures the real decision process.

Minitab’s attribute agreement documentation distinguishes agreement within and between appraisers. Those views answer different questions: whether one person repeats a decision and whether different people make the same decision.

Select representative assessment items

Include clear acceptable and unacceptable examples, plus conditions near the practical decision boundary. Identify the feature being rated and the applicable criterion. Avoid a study containing only obvious examples that do not resemble the disagreements occurring in production.

Use physical samples or images appropriate to the inspection task. An image study may evaluate interpretation of the image without capturing lighting, focus, access, or handling differences at the actual station. State that limitation rather than treating every form of assessment as equivalent.

Preserve independent ratings

Present repeated items in an order that reduces recognition and discussion effects. Inspectors should not see each other’s ratings before completing the independent assessment. Agreement produced by conversation is useful for training but answers a different question from independent inspection performance.

Investigate the disagreement pattern

1. Check consistency within each inspector.
2. Compare decisions between inspectors.
3. Compare with the justified reference where available.
4. Identify recurring boundary conditions.
5. Clarify the method and verify improvement with new assessments.

A high overall agreement percentage can conceal poor performance on a rare but important condition. Examine the actual decision categories and disagreement examples. Also distinguish false acceptance from false rejection instead of treating their practical consequences as identical.

Do not define the reference solely by majority vote when the requirement needs a technical interpretation. Resolve the acceptance basis with the appropriate engineering evidence and document it. Preserve the original ratings when conducting that review. Record the clarified rule separately so the before-and-after assessment remains interpretable and training effects are visible.

The useful output is a clearer inspection method, representative examples, and evidence that inspectors apply it consistently. It should explain which conditions remain difficult and how those conditions will be escalated, rather than reducing every inspection question to one agreement number.