ISO 9001: 2015 - Internal Audit Checklist for Quality Control Process in Manufacturing
Master ISO 9001 Quality Control audits with this comprehensive tabular QC checklist. This guide provides practical audit questions covering finished goods inspection, sampling methods, incoming material verification, measuring instrument calibration, nonconformity control, and corrective actions. Quick reference format for efficient on-site QC auditing with focus on inspection effectiveness and measurement traceability.
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✅ Finished Goods Inspection (Clause 8.6)
Verify that all finished products are inspected before release to customers. Check that inspection authority is defined and records are maintained for all released products.
| CLAUSE | AUDIT QUESTION | WHAT TO LOOK FOR |
|---|---|---|
| 8.6 | Are all finished products inspected before they are sent to customers? | 100% or sampling-based inspection procedures documented, inspection workstations, inspection equipment, records showing inspection before dispatch |
| 8.6 | Can you show me the inspection records for products released this week? | Dated inspection records, inspector signatures, product acceptance/rejection status, lot numbers, traceability to batch records |
| 8.6 | Who has authority to approve and give final release order for shipment? | Defined release authority, documented in QMS, sign-offs from authorized personnel, prevention of unauthorized releases |
📊 Sampling Methods and Inspection Plans (Clause 8.6)
Verify that sampling methods are defined, documented, and appropriate for the product type. Check that sampling plans meet customer requirements and are consistently applied.
| CLAUSE | AUDIT QUESTION | WHAT TO LOOK FOR |
|---|---|---|
| 8.6 | What sampling method is used to select samples from finished goods? (e.g., 5 samples/lot, 5%/lot, 100%?) | Documented sampling procedures, justified sampling percentages, AQL levels defined, customer requirements referenced, statistical basis |
| 8.2.3 | Are inspection plans reviewed before production begins for new or modified products? | Inspection plans approved and signed, sampling method defined, acceptance criteria clear, critical vs. major vs. minor characteristics identified |
⚠️ Key Point: Sampling plans must be justified and documented. Random or inconsistent sampling creates audit nonconformities.
📥 Incoming Material Inspection (Clause 8.4.3)
Verify that raw materials and purchased components are inspected before use in production. Check that acceptance criteria are defined and incoming inspection records are maintained.
| CLAUSE | AUDIT QUESTION | WHAT TO LOOK FOR |
|---|---|---|
| 8.4.3 | Is incoming inspection performed on raw materials and purchased components before use? | Receiving inspection station, visual inspection procedures, dimensional checks, material certificates verified, lot segregation until approved |
| 8.4.3 | What are the acceptance criteria for incoming materials? | Visual acceptance standards documented, dimensional tolerances defined, material certificates required, supplier certifications referenced |
| 8.4.3 | Are incoming inspection records maintained? | Receiving inspection reports, dated records, material batch numbers, supplier identification, pass/reject documentation, signatures |
| 8.4.3 | What is done with rejected incoming materials? | Returned to supplier, scrapped, reworked (with approval), documented disposition, nonconformity report filed, supplier notification |
📏 Measuring Instruments and Resources (Clause 7.1.5)
Verify that adequate measuring equipment is available for QC inspection. Check that instruments are suitable for the accuracy required and that an inventory is maintained.
| CLAUSE | AUDIT QUESTION | WHAT TO LOOK FOR |
|---|---|---|
| 7.1.5.1 | What measuring instruments (gauges, calipers, micrometers, CMM) are used in QC? | Documented instrument inventory, appropriate accuracy for product tolerances, suitable for critical characteristics, well-maintained equipment |
| 7.1.5.1 | Are measuring instruments appropriate for the product specifications? | Accuracy ratios acceptable (typically 4:1 or better), capability studies documented, instruments meet customer requirements |
🔧 Calibration and Measurement Traceability (Clause 7.1.5.2)
Verify that all measuring instruments are calibrated at regular intervals to ensure measurement validity. Check for traceability to national standards and out-of-calibration procedures.
| CLAUSE | AUDIT QUESTION | WHAT TO LOOK FOR |
|---|---|---|
| 7.1.5.2 | Are measuring instruments calibrated at regular intervals? | Calibration schedule maintained, calendar intervals or usage-based schedules, service contracts with accredited labs, internal calibration with standards |
| 7.1.5.2 | Can you show calibration certificate or sticker on this gauge showing it is within calibration? | Current calibration labels with expiration dates, color-coded tags (green=OK, red=out), certificates with traceability to NIST or equivalent |
| 7.1.5.2 | What happens when a measuring instrument is found to be out of calibration? | Instrument removed from service immediately, potential affected products identified, records checked for recent use, corrective action initiated if needed |
Audit Tip: Randomly select 5-10 measuring instruments and verify calibration status. Check at least 2 calibration certificates for traceability.
❌ Control of Nonconforming Outputs (Clause 8.7)
Verify that rejected or defective products are clearly identified and controlled to prevent accidental use. Check that nonconformity reports are completed and dispositions documented.
| CLAUSE | AUDIT QUESTION | WHAT TO LOOK FOR |
|---|---|---|
| 8.7 | How do you identify and mark rejected or defective products? | Red tags or labels, rejection boxes clearly marked, quarantine areas segregated, visual indicators preventing shipment to customers |
| 8.7 | Is a Non-Conformity Report (NCR) or rejection form filled out for each defective item? | NCR forms completed with date, product ID, defect description, quantity affected, authorized signature, disposition (scrap/rework/return) |
| 8.7 | If customer returns a defective product, how is it handled and documented? | Returned goods receiving inspection, NCR completed with "customer return" noted, root cause investigation, corrective action triggered if systemic issue |
⚠️ Red Flag: Defective products must never be shipped. Ensure clear identification and immediate isolation procedures.
🔍 Nonconformity and Corrective Action (Clause 10.2.1)
Verify that quality problems trigger corrective action investigations to identify root causes and implement preventive measures. Check that effectiveness is verified.
| CLAUSE | AUDIT QUESTION | WHAT TO LOOK FOR |
|---|---|---|
| 10.2.1 | When a quality problem is found, is a corrective action form filled out? | Corrective action forms for all significant defects, documented problem description, date initiated, assignment to responsible person |
| 10.2.1 | Who investigates the root cause of quality problems? | Designated quality/engineering personnel, root cause analysis methodology documented, evidence investigation conducted before solution |
| 10.2.1 | Are corrective actions defined and implemented to prevent problems recurring? | Specific corrective actions documented, responsible person assigned, target completion date set, implementation evidence collected |
| 10.2.1 | Is the effectiveness of corrective action verified after implementation? | Follow-up inspection after corrective action, repeat defects monitored, effectiveness check documented, actions closed with verification |
| 10.2.1 | Can you show nonconformity reports and corrective action records from last 3 months? | Complete NCR history, open and closed actions tracked, timely closure, corrective action effectiveness evident from reduced repeat defects |
📈 Monitoring, Measurement and Analysis (Clause 9.1.1)
Verify that QC data is analyzed to identify trends and quality patterns. Check that acceptance criteria are clearly communicated to inspectors.
| CLAUSE | AUDIT QUESTION | WHAT TO LOOK FOR |
|---|---|---|
| 9.1.1 | What quality characteristics or parameters does the QC team monitor and measure? | Defined critical-to-quality (CTQ) characteristics, documented specification limits, measurement frequency established, data collection consistent |
| 9.1.1 | Are acceptance criteria or specifications clearly defined and available to QC inspectors? | Visual standards available, specification sheets at inspection stations, tolerance limits clearly marked, defect classification documented |
| 9.1.1 | How are inspection results analyzed (charts, trends, statistics)? | Control charts maintained, trend analysis performed, defect data tracked, management reports generated, data used for decision-making |
👥 QC Inspector Competence and Training (Clause 7.2)
Verify that QC inspectors are trained and competent on inspection methods and equipment. Check that training records are maintained and new inspectors are qualified before independent work.
| CLAUSE | AUDIT QUESTION | WHAT TO LOOK FOR |
|---|---|---|
| 7.2 | Are QC inspectors trained on inspection methods and equipment? | Training records for all inspectors, training on measurement techniques, equipment operation, specification understanding, defect identification |
| 7.2 | Can you show training certificates or records for QC staff? | Training attendance records, training dates documented, competency assessments completed, certificates on file, refresher training scheduled |
| 7.2 | Are new inspectors trained before conducting independent inspections? | Formal training period documented, supervised inspection practice, competency verified before independent authorization, training sign-off by supervisor |
Interview Question: Ask a random QC inspector to explain acceptance criteria for a characteristic and show how they perform a specific measurement. Verify competence through demonstration.
📋 QC Documentation and Records (Clause 7.5)
Verify that inspection procedures are documented and QC records are properly maintained. Check that external documents are controlled and current.
| CLAUSE | AUDIT QUESTION | WHAT TO LOOK FOR |
|---|---|---|
| 7.5 | Are inspection procedures documented and available to all QC staff? | Inspection procedures accessible (printed or digital), step-by-step instructions clear, sampling methods defined, acceptance criteria included |
| 7.5 | Are inspection records properly filed and easily retrievable? | Organized inspection records by date or lot, systematic filing system, records retention policy documented, easy access for audits or inquiries |
| 7.5 | How are external documents (standards, specifications, customer requirements) controlled and kept current? | Latest versions used, obsolete versions removed, customer specification updates implemented, external standard references current |
📌 QC Audit Best Practices & Common Findings
Before the Audit
| 📋 Review QC Procedures | Study inspection plans, sampling methods, and acceptance criteria to understand baseline compliance |
| 📊 Analyze Defect Data | Review recent QC records, defect patterns, and corrective actions to focus audit on risk areas |
| 🔍 Prepare Audit Tools | Bring this checklist, measuring instruments for verification, camera for documentation |
| 📢 Notify QC Team | Schedule audit time with QC manager to ensure key personnel availability |
During the Audit
| 👀 Observe Active Inspection | Watch inspectors performing work; verify procedures match actual practice |
| ✅ Verify Calibration | Check 5+ random instruments for calibration labels and current certificates |
| 🔄 Test Traceability | Select recent products from inspection records and verify traceability to inspection documentation |
| 💬 Interview Inspectors | Ask inspectors to explain specifications, measurement techniques, and defect criteria |
| 📸 Document Evidence | Photograph inspection setups, calibration labels, records, and storage areas |
| 🎯 Check Recent Records | Review inspection records from past 2 weeks to verify completion and authority signatures |
After the Audit
| 📝 Compile Findings | Document all observations with evidence; distinguish conformities vs. nonconformities |
| 🏆 Classify Severity | Major nonconformities = systemic inspection failures; Minor = isolated gaps |
| 📢 Provide Feedback | Share findings with QC manager; discuss improvement opportunities |
| ✏️ Request Actions | For each nonconformity, require specific corrective actions with root cause analysis |
| ✅ Follow-Up | Verify corrective actions implemented and effective in next audit |
🚩 Common QC Audit Findings (Watch for These)
| No Inspection Records | Finished goods released without documented evidence of inspection |
| Uncalibrated Tools | Measuring instruments used without current calibration certificates |
| Unclear Acceptance Criteria | Inspectors unclear on specifications or tolerances; inconsistent acceptance decisions |
| No Sampling Plan | Sampling method not documented or random sampling without justification |
| Missing NCR Forms | Defects identified but no nonconformity reports completed |
| No Corrective Actions | Repeated defects but no investigation or corrective action taken |
| No Incoming Inspection | Raw materials used without verification of acceptance criteria |
| Untrained Inspectors | No evidence of training for QC staff or new inspectors unsupervised |
| No Data Analysis | Inspection data collected but not analyzed for trends or improvement |
| Defective Products Shipped | Failed products mixed with good product or quarantine not enforced |
✨ Conclusion
This comprehensive ISO 9001 Quality Control audit checklist in tabular format covers all critical QC activities from incoming material inspection through finished goods release and corrective action. The quick-reference design enables systematic on-site auditing while ensuring no inspection area is overlooked. Effective QC audits verify that inspection is not just performed but done with proper authority, documentation, and measurement integrity.
Remember: QC is the last line of defense against defective products reaching customers. Ensure your QC audit is thorough, evidence-based, and linked to corrective action effectiveness for continuous improvement.
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