ISO9001 System Document Package (35) | Process Inspection Work Instruction

Document Description: This work instruction is a lower-level supporting document for the "Production Process Control Procedure" (Package No. 17) and the "Monitoring and Measurement Resources Control Procedure" (Package No. 10). It belongs to the third-level documents of the quality management system (QMS) and is used to implement the requirements of "monitoring and measurement activities at appropriate stages" in clause 8.5.1 "Control of production and service provision" and clause 8.6 "Release of products and services" of ISO 9001:2015. This document specifies the detailed operational actions for the IPQC (process inspection) position, including where to set inspection points, when to perform first article inspection, how often to conduct patrols, how many samples to inspect, which items to check, what measuring tools to use, and who must stop the line within a few hours if an abnormality is detected. It is applicable to all production enterprises with manufacturing processes (such as machining, assembly, injection molding, stamping, welding, painting, electronic assembly, food and packaging, etc.). For enterprises primarily engaged in assembly and debugging with minimal process parameter fluctuations, the patrol inspection frequency and items can be trimmed according to clause 2.3, but the first article inspection and key process monitoring must not be canceled. This document can be directly published and used as a third-level document by enterprises, and when in use, the organization name, department code, process name, control characteristics, and frequency should be replaced with actual values.

1. Purpose

To standardize the process inspection (IPQC) activities of our company, clarify the principles for setting inspection points, the requirements for first article inspection and patrol inspection, the methods for process parameter monitoring, the criteria for judgment, status identification, and the path for abnormality handling. This ensures that the process remains under control, nonconforming products are promptly detected and intercepted within the process, and prevents the batch production of nonconforming products and their flow into the next process. This work instruction is specifically formulated for these purposes.

2. Scope of Application

2.1 This work instruction applies to all process inspection activities from the start of raw material production to the completion of finished products, covering all stages such as machining, assembly, debugging, and packaging.

2.2 This work instruction covers the following aspects: inspection preparation, setting of inspection points, first article inspection, process patrol inspection, fixed-point inspection and process completion inspection, monitoring of key and special process parameters, application of process capability and statistical process control (SPC), judgment and status identification, handling of nonconformities and abnormalities, and record and data management.

2.3 The following scenarios can be executed according to a simplified process, but the simplification criteria must be proposed by the process department, approved by the quality manager, and recorded:

• Manual assembly, single-piece small-batch production: Replace fixed-point inspection with first article inspection and patrol inspection, with a patrol frequency of no less than once every 2 hours.
• Fully automated continuous production lines (such as automatic surface mount technology, automatic filling): Replace manual full inspection items with online equipment detection and automatic parameter recording, retaining at least two manual patrols per shift.
• Simple processes (deburring, cleaning, labeling): Only set process completion inspection, without dedicated inspection points.

2.4 This work instruction does not replace the control plan (Control Plan) and SIP (Inspection Work Instruction). When customer special requirements, process documents, or drawings are more stringent than this document, the more stringent requirements should be followed.

3. Responsibilities

3.1 Quality Department (IPQC Team): Responsible for proposing and maintaining the setting of process inspection points, implementing first article inspection and patrol inspection, confirming the sampling of process parameters, judgment and status identification, isolating and reporting nonconforming processes, filling out inspection records, and statistical process quality data. Responsible for compiling the monthly process quality report.

3.2 Production Department: Responsible for organizing production according to the control plan and process documents, reporting first articles at the specified frequency, stopping machines and lines promptly according to abnormal handling instructions, isolating and reworking nonconforming work-in-progress, and filling out and managing the flow cards.

3.3 Technical Department/Process Department: Responsible for compiling and maintaining the control plan, process specifications, and SIP, specifying inspection points, control characteristics (including key characteristics and important characteristics), specifications and tolerances, inspection methods, frequency, and measuring tools. Responsible for process improvement plans when process capability is insufficient, and resolving technical issues with disputes.

3.4 Equipment Department: Responsible for the inspection, maintenance, and repair of production equipment and tooling, investigating the root causes of batch abnormalities caused by equipment parameter loss of control, and verifying the capability of mass production equipment.

3.5 Management Representative/Quality Manager: Responsible for approving the setting of inspection points, special process release criteria, stop-line standards, and concession acceptance conclusions. Responsible for making decisions on major batch quality abnormalities.

3.6 Internal Auditors/Audit Interface Personnel: Responsible for verifying the authenticity, completeness, and traceability of process inspection records.

4. Work Procedures

4.1 Inspection Preparation

4.1.1 The Quality Department should work with the Process Department to compile the "Process Inspection Work Instruction" (SIP) for each process that requires inspection. The content should at least include: process number and name, applicable product and drawing number, inspection items, control characteristics (including key characteristics and important characteristics), specification requirements and tolerances, inspection methods, measuring tools used, inspection frequency and sampling quantity, judgment criteria, abnormal reporting path, and record form number. The SIP should be reviewed, released, and revised in sync with the process documents.

4.1.2 Before implementing the inspection, the inspector should confirm: the held SIP and process documents are the current valid versions; the measuring tools are within the calibration validity period and have no visible damage; the positioning benchmarks of the measuring tools are consistent with the process benchmarks; the inspection site meets the requirements for illumination, environmental temperature, and cleanliness; and necessary safety precautions are in place.

4.1.3 Inspectors should be trained and qualified for their positions; for special inspection items such as non-destructive testing, electrical safety, pressure testing, and microbial limits, they must hold valid qualification certificates.

4.1.4 Before production starts, the Production Department should complete the first article preparation: confirm that equipment, tooling, cutting tools, molds, programs, material batches, and personnel are all in place, and verify the information from the previous batch's flow card.

4.2 Setting of Process Inspection Points

4.2.1 Inspection points should be set at locations where "nonconformities can be effectively intercepted," following these principles:

• After processes corresponding to key characteristics (safety, regulations, customer key requirements), inspection points must be set, and these points should be stop-line inspection points. Production can only proceed after the inspection is passed.
• After processes prone to systematic defects (such as mold forming, welding, painting), inspection points should be set.
• Before processes where the value of the next stage significantly increases and post-process rework is not advisable, inspection points should be set to avoid defects entering high-cost stages.
• In cases where multiple processes are continuous and defects have a common source, inspection points can be combined, but the combined points must still cover all control characteristics.

4.2.2 Inspection points are divided into three categories: First Article Inspection Points (after line change, mold change, material change, personnel change, program change, or after equipment repair and restart), Patrol Points (mobile inspections during routine batch processes), and Fixed-Point Inspection Points (fixed confirmation after key processes). Each inspection point should be registered in the control plan and clearly marked at the site with signs or work station kanbans.

4.2.3 Once inspection points are determined, they cannot be canceled or reduced in frequency by production personnel. If adjustments are necessary, they must be proposed by the Process Department, approved by the Quality Manager, and recorded in the control plan.

4.3 First Article Inspection

4.3.1 In any of the following scenarios, the Production Department must report the first article for inspection and must not continue batch production until the first article inspection is completed and judged:

• At the start of each shift and each production line change.
• After changing molds, tooling, cutting tools, fixtures, or equipment parameters and programs.
• After changing material batches or suppliers (including different batch numbers from the same supplier).
• After changing operators or machine adjusters.
• After equipment repair and downtime exceeding 4 hours.
• For the first production after the last production batch had nonconformities and corrective actions were taken.

4.3.2 The first article inspection follows the "three-inspection system": self-inspection by the operator, mutual inspection by the team leader, and specialized inspection by IPQC. All three inspections are recorded, and the specialized inspection conclusion serves as the final judgment.

4.3.3 The number of first articles is generally one piece; for multi-cavity molds, multi-position equipment, and group processing processes, one piece should be taken from each cavity, each position, and each group (i.e., all cavity first articles). For destructive inspection items, one piece per shift can be sampled.

4.3.4 The first article inspection items should cover all control characteristics of the process as specified in the control plan, including appearance, dimensions, function, assembly fit, and identification and traceability information. Key characteristics must be 100% measured and recorded.

4.3.5 First article judgment:

• All items are qualified: IPQC signs "First article qualified, agree to batch production" on the flow card and first article inspection record, and production can continue.
• Any item is unqualified: IPQC judges "First article unqualified," and the Production Department immediately adjusts and resubmits for inspection. If three consecutive first articles are unqualified, the Process Department must intervene for analysis, and if necessary, report to the Quality Manager.
• First article unqualified but qualified after rectification: the first article should be marked and stored separately, and must not be mixed with the normal batch.

4.3.6 After the first article is qualified, it should be labeled with a "First article" tag and kept as a sample at the workstation until the batch is completed. After the batch is completed, the sample should be disposed of as a nonconforming product or a normal product, and must not flow directly into the next process without any record.

4.4 Process Patrol Inspection

4.4.1 The patrol inspection frequency is set according to the importance of the process. The suggested baseline is as follows (companies can adjust according to actual conditions and specify in the SIP):

4.4.2 The patrol route should cover all work-in-progress workstations and should not be a mere formality for record-keeping. If two consecutive pieces with the same defect or the same defect at the same workstation are found during patrol inspection, proceed directly to section 4.8 for abnormal handling.

4.4.3 Patrol inspection items include: actual measurement of product dimensions and appearance, assembly fit, whether the work method is consistent with the process documents, whether measuring tools are used correctly, whether equipment parameters are within the set range, whether tooling and fixtures are worn or loose, and whether work-in-progress identification and flow cards are complete. Verify if the previous batch's nonconformities have been closed.

4.4.4 Patrol inspection records should be filled out with actual measurement values for each item, not just summarized as "qualified." Both the inspector and the team leader (or the operator of the inspected workstation) should sign to confirm the facts.

4.4.5 If the inspector finds that the operator has changed process parameters without authorization, skipped processes, or used uncalibrated measuring tools, IPQC has the authority to immediately stop the process and report to the Production Department and Quality Department, and handle according to section 4.8.

4.5 Fixed-Point Inspection and Process Completion Inspection

4.5.1 After the completion of key processes, IPQC should perform fixed-point inspections at designated inspection points according to the items and sampling plan specified in the SIP. After passing the inspection, sign the flow card and stamp it with the "Process Inspection Qualified" seal to allow the product to flow to the next process.

4.5.2 Batches without flow cards or unsigned flow cards can be rejected by the next process. After rejection, the Production Department should complete the inspection procedures and provide the reason.

4.5.3 For processes requiring quantitative handover between processes (such as counting, weighing, and mixing), verify the quantity and identification during fixed-point inspection to prevent batch mixing and material confusion.

4.5.4 Nonconforming products found during fixed-point inspection should be immediately isolated, marked separately, and placed in the red nonconforming area, with records kept on the flow card and the "Process Nonconformity Handling Form."

4.6 Process Parameter Monitoring for Key and Special Processes

4.6.1 For special processes such as heat treatment, welding, painting, bonding, injection molding, and sterilization, process parameter monitoring should be the primary control method: record parameters such as temperature, time, pressure, speed, current, and vacuum degree according to the process documents, and verify if they fall within the process window.

4.6.2 Parameter records should be true and continuous, and should not be filled in retrospectively. If automatic recorders or equipment data collection are used, confirm that the equipment is within the calibration validity period and that the data can be exported and traced.

4.6.3 If parameters exceed the process window, even if the product appearance and dimensions are qualified, IPQC should judge it as a process abnormality and handle it according to section 4.8. For work-in-progress affected by the parameters, expand the sampling and assess the traceability range.

4.6.4 Operators and equipment capabilities for special processes should be confirmed or re-confirmed according to regulations (such as welding process evaluation, sterilization validation). Production can only proceed if the confirmation records are within the validity period.

4.7 Process Capability and Statistical Process Control

4.7.1 For key characteristics and important characteristics in stable batch production, use control charts (mean-range charts, individual-moving range charts, etc.) to monitor the process and plot points according to the frequency specified in the SIP.

4.7.2 The abnormal judgment rules for control charts should at least include: a single point exceeding the control limit; seven consecutive points on the same side of the center line; six consecutive points increasing or decreasing; two out of three consecutive points outside two standard deviations. If any of these occur, the Process Department and Quality Department should jointly analyze the cause.

4.7.3 Process capability index (Cpk) requirements: key characteristics should be no less than 1.33, and important characteristics should be no less than 1.00. If the requirements are not met, initiate process improvements and increase inspection frequency until the capability meets the standard.

4.7.4 The control limits of the control chart should be calculated from process data and should not be replaced by specification tolerances. The specification lines and control lines should be marked on the chart simultaneously for easy on-site identification.

4.8 Judgment, Identification, and Status Management

4.8.1 The process inspection conclusions should use three status identifiers: Green "Qualified/Flowable", Yellow "Pending Inspection/Pending Judgment", Red "Unqualified/Isolated". The form of identification can be labels, cards, container colors, or area demarcation.

4.8.2 Once a status is identified, it cannot be changed without IPQC's approval. The Production Department must not privately move, cover, or remove the identification.

4.8.3 Work-in-progress in the pending inspection status should be stored in the pending inspection area and must not flow into the next process. If space limitations prevent setting a dedicated area, clear physical separation measures (such as barriers, pallets, and dedicated turnover boxes) must be implemented.

4.9 Handling of Process Abnormalities and Nonconformities

4.9.1 If any of the following scenarios occur, IPQC has the authority to issue a stop-machine and stop-line order, and the Production Department must immediately comply:

• Three consecutive first articles are unqualified.
• Two consecutive pieces with the same defect or repeated defects at the same workstation are found during patrol inspection.
• Key characteristics are unqualified.
• Special process parameters exceed the process window and the impact range is unclear.
• Abnormal rules are triggered in the control chart.
• Measuring tools are out of calibration, equipment is abnormal, or process documents are missing.

4.9.2 After stopping the machine and line, handle according to the following path:

1. Immediate Isolation: Remove all work-in-progress produced since the last qualified inspection point, mark them with a red label, and place them in the nonconforming product area.
2. Range Definition: Combine inspection records and flow cards to define the start and end times, quantities, and flow directions of the suspicious batches.
3. Cause Analysis: Jointly analyze with the Production Department, Process Department, Equipment Department, and Quality Department to distinguish between random and systematic causes.
4. Handling Decision: The Quality Manager (in consultation with the Technical Department if necessary) decides on rework, repair, concession acceptance, or scrap. Concession acceptance must have technical review opinions, customer requirement verification, and authorized signatures.
5. Recovery Conditions: Production can only resume after confirming that the cause has been eliminated, the first article is re-inspected and qualified, and relevant parameters are restored to within the process window.
6. Subsequent Intensification: Intensify inspection frequency for at least three consecutive batches (or one shift) after resuming production, and return to normal frequency after stability is confirmed.
7. Corrective Actions: For systematic causes, issue a corrective action form according to the "Nonconforming Products and Corrective Actions Procedure" (Package No. 27), and track verification until closure.

4.9.3 For suspicious products that have already flowed to the next process or been assembled and stored, trace back and isolate according to the range defined in item 2 of section 4.9.2, and trace the batch flow according to the "Identification and Traceability Control Procedure" (Package No. 18).

4.9.4 Reworked and repaired products must be re-inspected, with inspection items no less than the original inspection items, and the "rework/repair" label and number of times should be noted in the records. If the same product is reworked more than twice, the Technical Department should assess whether it should be downgraded or scrapped.

4.10 Record and Data Management

4.10.1 Process inspection records include: "First Article Inspection Record," "Process Patrol Inspection Record Form," "Process Flow Card," "Process Nonconformity Handling Form," "Process Capability Analysis Form," and "Stop-Machine and Stop-Line Notice."

4.10.2 Records should be filled out in real-time on-site, with clear handwriting, no use of pencils, and no alterations. If corrections are needed, draw a single line, write the correct value, and sign with the date, without covering the original writing.

4.10.3 Records should be retained for no less than the product's life cycle or the period required by customers/regulations, generally no less than 3 years. For records involving safety and regulatory compliance, the retention period should be no less than 5 years after the product is discontinued or as required by regulations.

4.10.4 The Quality Department should compile the monthly process quality report, summarizing the first-time pass rate, nonconformity rate by process, number of stop-line incidents, and stop-line duration, as well as the distribution of process capability indices, to provide input for management review and continuous improvement.

4.11 Process Flow (Textual Flowchart)

Production Preparation (Equipment/Tooling/Materials/Personnel in Place)
        ↓
First Article Production and Three-Inspection (Self-Inspection → Mutual-Inspection → IPQC Special-Inspection)
        ↓
First Article Judgment ──Unqualified──→ Adjust Process → Resubmit for Inspection (If Three Consecutive First Articles are Unqualified, Report to Process Department/Quality Manager)
        ↓ Qualified
Batch Production + Process Patrol Inspection (Sample According to Frequency, Record Actual Measurement Values)
        ↓
Fixed-Point Inspection/Process Completion Inspection
        ↓
Judgment ──Unqualified──→ Stop-Machine and Stop-Line → Isolation → Range Definition → Cause Analysis → Handling Decision → Recovery Condition Confirmation → Intensified Inspection → Corrective Action Closure
        ↓ Qualified
Sign Flow Card → Mark as Qualified → Flow to Next Process
        ↓
Record Archiving + Monthly Report Statistics + Process Capability Analysis

4.12 Form References

5. Related Records

5.1 First Article Inspection Record: Fields include inspection date, shift, product name and drawing number, process number and name, equipment/mold number, material batch, operator, inspection items, specification requirements, actual measurement values, judgment, inspector, team leader confirmation, and handling opinion. Example: 2026-09-13/Day Shift/Part A/Process 20 Precision Turning/Equipment CNC-03/Material Batch L0925/Operator XX/Outer Diameter φ20.00±0.05/Actual Measurement 20.02 to 20.03/Judgment Qualified/First Article Qualified, Agree to Batch Production.

5.2 Process Patrol Inspection Record Form: Fields include patrol time, process and workstation, product batch, patrol items, sampling quantity, actual measurement values or status, description of abnormalities found, handling measures, inspector, and confirmation by the inspected workstation. Example: 10:30/Process 20 Precision Turning Workstation 2/Batch 260913-A/Outer Diameter and Appearance/Sample 4 Pieces/20.01, 20.02, 20.03, 20.02, No Burrs/No Abnormalities/—/XX/XX.

5.3 Process Flow Card: Fields include product name and drawing number, batch number, process sequence number and name, input quantity, completed quantity, qualified quantity, unqualified quantity, inspector's signature, date, and next process receiving signature. Example: Part A (Drawing Number XX-102)/Batch 260913-A/Process 20 Precision Turning/Input 500/Completed 498/Qualified 496/Unqualified 2/XX/2026-09-13/Process 30 Received.

5.4 Process Nonconformity Handling Form: Fields include discovery time, discovery process, product batch, unqualified quantity, description of nonconformities and physical photo numbers, preliminary cause analysis, handling method (rework/repair/concession/scrap), responsible department, approver, corrective action number, and verification conclusion and closure date.

5.5 Process Capability Analysis Form: Fields include characteristic name, specification and tolerance, sample size, mean, standard deviation, Cp, Cpk, control chart type, analysis conclusion, and improvement requirements.

5.6 Stop-Machine and Stop-Line Notice: Fields include trigger time, trigger standard clause, description of trigger facts, quantity and batch of involved work-in-progress, person issuing the stop-line instruction, production department confirmation, recovery conditions, and recovery time, and verification conclusion.

Usage Instructions

1. How to Modify According to Actual Conditions

1. Inspection Point and Frequency Adaptation: The setting principles in section 4.2 and the frequency table in section 4.4.1 are general benchmarks. Companies with simple product structures, stable processes, and good historical data can relax the frequency of general processes, but the inspection points and frequency for key characteristics can only be intensified, not relaxed. For industries such as automotive, medical devices, and aviation, customer special requirements (CSR) and industry standards should be verified simultaneously, and if they are more stringent than this document, they should be followed, with the source noted in the control plan.

2. Organization and Position Adaptation: Small and medium-sized enterprises can combine IPQC with IQC/FQC and have the same person handle both, but key characteristic inspections should have a verifier. For multi-shift production on a single production line, it should be clearly defined whether the first article should be redone during shift changes (it is recommended to always do the first article during shift changes). For multi-site or outsourced processing enterprises, the agreement should specify who performs the process inspection, how records are transmitted, and how abnormalities are escalated to avoid "vacuum processes" where neither party inspects.

3. Process and Equipment Adaptation: Process names, equipment numbers, parameter windows, and measuring tool lists should be replaced with actual values for the company. If the company has implemented automated online detection, the online detection results can be used as the basis for patrol inspection in section 4.4, but manual sampling should be retained to verify the effectiveness of the online detection system.

4. Integration with Existing Documents: This work instruction and the "Production Process Control Procedure" have a hierarchical relationship. The principle content already in the procedure document does not need to be repeated, only the document number needs to be referenced. If the company has not yet compiled a control plan, it can temporarily use SIP and flow cards, but the control plan should be completed as soon as possible, otherwise, the setting of inspection points lacks systematic basis.

2. Audit Focus Points

• Whether the inspection points registered in the control plan are actually set on-site and have clear identification and work basis.
• Whether the first article inspection records cover all specified occasions such as line change, mold change, material change, personnel change, and equipment repair, and whether the record times match the production start times.
• Whether the first article and patrol records are filled with actual measurement values rather than just "qualified"; whether there are signs of retrospective filling (same time batch writing, time logic contradictions).
• Whether the patrol frequency is consistent with the document specifications; whether the randomness of sampling can be verified, and whether there is a tendency to sample only inspected items or appearance items.
• Whether the processes corresponding to key characteristics are inspected 100% or parameter-monitored as required by the document; whether parameter records are continuous and complete.
• Whether the control charts are truly plotted and whether there are analysis records and handling conclusions after abnormal rules are triggered.
• Whether there are stop-machine and stop-line instructions, whether the involved work-in-progress is actually isolated, and whether the conditions for resuming production meet the prerequisites for a qualified first article.
• Whether reworked and repaired products are re-inspected and whether the number of repairs is controlled.
• Whether the corrective action forms issued after abnormalities are closed and whether there is evidence of the effectiveness of the verification.
• Whether the monthly process quality report provides actual input for management review and whether the data matches the original records.

3. Common Errors

1. First Article Inspection is a Formality: Only the first article items are recorded, but actual production starts before the first article is judged; or the first article is directly released after self-inspection by the operator without specialized inspection by IPQC.
2. Missing First Article Inspection Occasions: Not redoing the first article after mold change, material change, personnel change, or equipment repair, using the conclusion from the previous batch, leading to systematic defects in batch production.
3. Patrol Inspection is a Formality: Signing off hourly without actual measurement, all records are "qualified," and do not match the actual workstation conditions; unable to trace any inspection actions when problems occur.
4. Records Only Summarize Conclusions: No actual measurement values, no measuring tool numbers, no signatures from both parties, making the inspection process unreproducible and leading to non-realistic records during audits.
5. Reluctance to Stop the Line: Continuing production to avoid affecting output when consecutive nonconformities are found, resulting in nonconforming products mixing and flowing, and rework costs and traceability ranges expanding exponentially.
6. Inadequate Isolation: Nonconforming work-in-progress is piled next to the production line and mixed with qualified products, relying only on verbal explanations, and failing to implement identification and isolation.
7. Parameter Records are Inaccurate: Temperature, time, and pressure records for special processes are filled in retrospectively according to standard values, unable to prove that the process is truly under control, a common point of serious nonconformities.
8. Control Charts are for Decoration: Points on the chart are neatly plotted without any abnormalities, but parameters are frequently adjusted without recording; control limits are replaced by specification tolerances, losing the meaning of process monitoring.
9. Data is Not Closed-Loop: Nonconformity records accumulate monthly but are never used for process improvement and capability enhancement, leading to repeated issues in different processes.
10. Resuming Production Without Verification: Production resumes immediately after cause analysis without redoing the first article or intensifying inspection, leading to the recurrence of abnormalities.

First article, patrol inspection, and abnormality escalation: Three gates to ensure process quality

Knowledge code: 2.3.1

Version: v20260809

Author: QTank QTank is dedicated to providing systematic professional knowledge, methodologies, and practical tools for quality management practitioners, helping enterprises continuously improve their quality capabilities.