1. Detection of Non-Conformance

Objective:
Identify any non-conformance at various inspection points during the manufacturing process.

Actions:

• Inspecting components during the assembly process (SMT, THT, manual soldering).

• Using Automated Optical Inspection (AOI), X-ray inspection, and manual visual inspection to spot defects.

• Common types of non-conformance can include:

  • Soldering defects (cold joints, bridging, tombstoning)

  • Component misplacement or incorrect orientation

  • Missing components

  • Incorrect solder paste application

  • Component damage or bent leads

  • Surface contamination or flux residue

2. Immediate Segregation of Non-Conforming Units

Objective:
Prevent defective units from proceeding further down the production line.

Actions:

• Segregate defective units immediately from the production line.

• Use visual tags or bins clearly marked for non-conforming units (Red bins for rejected items).

• Label the non-conforming products with a Non-Conformance Report (NCR) or identification tags that include:

  • Date and time of detection

  • Defect type

  • Inspection point (e.g., post-soldering, post-placement)

  • Operator ID

  • Serial number or lot number

• Keep these units in a designated quarantine area.

3. Root Cause Analysis (RCA)

Objective:
Identify the underlying cause of the non-conformance to prevent recurrence.

Actions:

• Perform a root cause analysis to determine why the defect occurred. This is typically done using techniques like:

  • 5 Whys: Ask “why” iteratively to trace back to the source of the problem.

  • Fishbone Diagram (Ishikawa): Identify potential root causes by analyzing the process, materials, people, equipment, environment, and methods.

  • Failure Mode and Effect Analysis (FMEA): Prioritize the severity and likelihood of various defects and their potential effects on the product.

• Review production data logs, machine parameters, and operator actions during the process to spot any abnormalities.

• Engage cross-functional teams (quality control, production, design engineers) to contribute their insights.

4. Corrective Actions (CAPA)

Objective:
Develop and implement corrective actions to eliminate the root cause and prevent recurrence of non-conformances.

Actions:

• Corrective Action: Implement immediate actions to fix the specific non-conformance detected (e.g., rework the defective unit).

  • Examples: Replace defective components, rework solder joints, adjust machine settings.

• Preventive Action: Implement long-term measures to prevent similar defects in the future (e.g., process changes, training, equipment maintenance).

  • Examples: Improve training programs, update work instructions, calibrate machines, upgrade equipment.

• Maintain documentation of all corrective and preventive actions taken, including results, timelines, and responsibilities.

5. Documentation and Non-Conformance Report (NCR)

Objective:
Ensure traceability and proper documentation for auditing, analysis, and future reference.

Actions:

• Fill out a Non-Conformance Report (NCR) for each non-conformance detected, including:

  • Description of the defect

  • Root cause analysis

  • Corrective and preventive actions (CAPA)

  • Responsible personnel

  • Date of issue and closure

  • Status of rework or rejection

• The NCR should be stored electronically in an ERP system or quality management system for easy retrieval during audits and reviews.

6. Rework Process

Objective:
Fix the non-conforming units that can be reworked and bring them back to compliance with the quality standards.

Actions:

• Determine if the unit can be reworked or needs to be scrapped.

• If rework is possible, ensure it is done under strict supervision and with detailed documentation.

• Common rework activities can include:

  • Soldering rework: Fixing cold joints, removing solder bridges, etc.

  • Component replacement: Changing faulty or incorrect components.

  • Component realignment: Correcting misplacements and ensuring proper orientation.

• After rework, conduct thorough testing and inspection to verify the unit meets all quality standards.

7. Approval and Clearance

Objective:
Once reworked or adjusted, ensure that non-conforming units are validated and cleared for further processing.

Actions:

• After rework or correction, the unit should be inspected and tested again to ensure compliance with the quality standards.

• The unit should go through another round of final inspection and functional testing.

• A quality engineer or designated authority must review the NCR and rework outcomes and approve or reject the product for final shipment.

8. Monitoring and Trend Analysis

Objective:
Track and monitor the frequency and types of non-conformance to identify patterns and prevent systemic issues.

Actions:

• Track non-conformance metrics, such as:

  • Defects per million opportunities (DPMO)

  • First pass yield (FPY)

  • Rework rate

  • Non-conformance frequency

• Use statistical process control (SPC) tools to monitor production trends and identify deviations.

• Regularly review NCR data to identify recurring issues and refine preventive actions.

9. Continuous Improvement

Objective:
Drive continuous improvement in the manufacturing process to reduce the occurrence of non-conformances.

Actions:

• Conduct Kaizen events (continuous improvement) to engage employees and engineers in identifying opportunities to improve processes.

• Analyze non-conformance trends, customer complaints, and production data to spot areas for improvement.

• Regularly update standard operating procedures (SOPs), work instructions, and training programs based on lessons learned from non-conformance incidents.

• Review and update quality control checklists and inspection protocols to ensure that defects are detected at earlier stages.

10. Final Disposition of Non-Conforming Units

Objective:
Ensure proper disposition of units that cannot be reworked and meet quality standards.

Actions:

• For units that cannot be reworked or fixed, they should be scrapped or returned to the supplier if the issue is related to material defects.

• The decision to scrap should be made based on the severity of the non-conformance and the potential impact on product functionality, safety, or customer satisfaction.

• Non-conforming scrap should be disposed of in an environmentally responsible manner and documented for traceability.

✅ Key Performance Indicators (KPIs) for Non-Conformance Management