Frequently Asked Question

Process-risk structure

PFMEA examines how a process can create a defect or fail to detect it. Start with a complete process flow including transport, inspection, storage, rework, and setup. For each step, identify the function, failure mode, effect, cause, prevention control, detection control, reaction, and owner. Prevention is generally stronger than relying only on final inspection.

Worked example

If a hole is drilled off-location, the cause may be fixture mislocation, the prevention control may be a keyed fixture, and the detection control may be in-process gauging. The control plan should use the same operation and characteristic identifiers as the PFMEA.

Engineering check

For Process Flow, PFMEA, and Control Plan Linkage, maintain traceability from requirement to risk, design output, evidence, and approval. Record the configuration, acceptance criterion, test or analysis conditions, open actions, and residual risk. A method is not complete when the document is filled in; it is complete when the evidence supports the decision and affected controls are updated.

Planning detail

For each controlled characteristic, identify the operation, specification, measurement method, frequency, record, reaction, containment quantity, adjustment rule, and restart authorization. Link the characteristic to the process-flow step and PFMEA failure mode. A control plan is effective only when the operator can execute it, the gauge is available and calibrated, and abnormal results trigger a defined response.

Planning detail

For each controlled characteristic, identify the operation, specification, measurement method, frequency, record, reaction, containment quantity, adjustment rule, and restart authorization. Link the characteristic to the process-flow step and PFMEA failure mode. A control plan is effective only when the operator can execute it, the gauge is available and calibrated, and abnormal results trigger a defined response.