In-plant Inspection是inspection of goodsThe core quality control methods in the industry, the industry practice, in-factory inspection usually account for a greater proportion of professional inspection work.
I. Overview of the core of the resident inspection
Factory inspection is the core quality control in the inspection industry, the industry practice, factory inspection usually account for a larger proportion of professional inspection work. There is a general cognitive misunderstanding in the industry that the factory inspection is simply squatting in the workshop to supervise the work of the workers, in fact, not, the factory inspection is a systematic quality control throughout the production process, the core principle is to “prevent problems before they occur”, rather than waiting for the finished product molding and then screening for defects. This note will systematically dismantle the core process of factory inspection, the industry's common standards and practical points, the content of both professional and practical, available to customers, purchasing practitioners, goods inspectors for reference.
The essence of the factory inspection, is the inspector on behalf of the customer, the factory production process to implement comprehensive supervision, covering incoming materials, production, finished products, factory four core links, while verifying the effective operation of the factory's existing quality system, and ultimately to ensure that the delivery of the product is fully in line with the standards agreed upon by the two sides. Its core basis mainly includes three categories: AQL sampling standards, ISO quality management system, andFactory AuditKey points, each control link is supported by clear industry norms rather than relying on personal experience judgment.
Second, the core process of factory inspection and operational standards
(i) Incoming material inspection: the first line of defense for quality
Incoming inspection is the first part of the factory inspection, but also the most easily overlooked quality control nodes, most factories have bulk quality problems, the root cause of unqualified incoming materials. The first job of the resident inspector is to check the incoming raw materials and components, and perform the inspection in strict accordance with the industry's common AQL sampling standards.
The core standard used here is ANSI/ASQ Z1.4 (equivalent to ISO 2859-1), which is the most widely used sampling inspection standard in the industry. Specific operation, according to the incoming batch size, defect level, the scientific setting of the sampling program: for example, a batch of 5000 parts, according to the general inspection level Ⅱ, fatal defects AQL is set to 0; the main defects AQL is set to 1.5; minor defects AQL is set to 4.0.
The sampling process should strictly follow the principle of randomness, taking samples from different batches and packages to prevent factories from deliberately selecting qualified samples to avoid inspection. The inspection covers the three dimensions of appearance, size and performance, and at the same time, we need to check the qualification certificates and test reports provided by suppliers to ensure that the incoming materials comply with the core requirements of “Verify that the product requirements have been met” in Chapter 8.6 of ISO 9001:2026. For unqualified incoming materials, it is necessary to immediately implement isolation, labeling operations, and issue a "Nonconforming Products Report" (NCR), to strictly prohibit the flow of unqualified incoming materials into the production process.
(ii) Process inspection: the key to batch defect control
Process inspection is the core focus of the factory inspection, but also a key link in the control of batch defects. Contrary to popular belief, process inspection is not a full-time watchman, but a targeted monitoring of key processes, key control points, and strict compliance with the ISO 9001 system of “process control” requirements, to ensure that the production process is in full compliance with the work instructions (WI) and standard operating procedures (SOP).
The process inspection hands-on focus includes the following:
1. First article inspection:After the start of each batch of production, the first 3-5 products need to be inspected to check whether the product size, process, appearance is in line with the agreed standards, the first piece of qualified inspection before the start of mass production. The first piece of inspection records need to be signed by the relevant personnel to confirm and retain archives, which is the core means of avoiding batch mis-production.
2. Regular inspections:In accordance with the preset frequency, the key processes such as injection molding, welding, assembly and other random checks, focusing on checking whether the production parameters are up to standard, and whether the operators are executing the operation according to the specifications, and at the same time, verifying the equipment point inspection records and calibration certificates of the measuring instruments - all the measuring instruments (e.g., vernier calipers, torque wrenches, etc.) must be within the valid calibration period, which is the Ensure the accuracy of inspection data.
(iii) Finished product inspection: the last firewall before leaving the factory
Finished product inspection is the last line of quality defense before the products leave the factory, which directly determines whether the products can be delivered normally. Finished product inspection also follows the AQL sampling standard, the larger the batch, the higher the sampling ratio, and the inspection items cover all the indicators agreed by both parties, such as appearance, size, function, packaging, labeling, and so on.
According to ISO 9001:2026 Chapter 8.6 requirements, the release of finished products need to meet two core conditions at the same time: one is the inspection results in line with the preset acceptance criteria, and the other is to have written information that can be traced back to the authorized release personnel. After passing the inspection, it is necessary to issue a “finished product factory inspection report”, clear inspection date, inspectors, inspection data and release conclusions; if the inspection fails, the product is strictly prohibited from leaving the factory, requiring the factory to rework, rework and re-inspection until qualified; if it can not be rectified, then the evaluation of the conclusions of the implementation of the end-of-life treatment, the whole process is not allowed to "exceptions to release! The whole process does not allow "exceptions to the release", unless the authorized personnel and the customer's written approval, and need to retain a complete record of approval.
Third, the factory inspection additional core work: factory audit
Factory inspection is not only for the product itself, the factory's quality system, production capacity, management level, directly affect the stability of product quality, so the factory audit is also one of the core work of the factory inspection. Audit work is mainly centered on the ISO 9001 system, focusing on three dimensions:
1. Review of documentation:Verify whether the factory quality manual, procedure documents, work instructions are complete and controlled version, whether the inspection records, equipment maintenance records, non-conforming products handling records are complete and standardized, to ensure that all documents comply with the system requirements and can be traced.
2. Production area audits:Check whether the production environment is in line with the product production requirements, whether the 5S management is in place (clear division of the area, material positioning and positioning), whether the production equipment is in good condition, whether there is no leakage phenomenon, whether the non-conforming products are set up exclusive isolation area and clear marking.
3. Personnel audit:Randomly check employee labor contracts and attendance records to confirm that employees have received professional job training and that quality inspectors are required to be licensed; at the same time, through employee interviews without the presence of factory managers, we understand the factory management style and whether the employee complaint mechanism is perfect.
Fourth, the factory inspection practice details and industry norms
In addition to the core inspection process and factory audits, in-factory inspection there are a number of industry default practical specifications, need to be strictly followed:
1. Daily need to the customer or the company's leadership, reporting the day's inspection, found that the quality of the problem and the way to deal with, to ensure that the information is synchronized in a timely manner;
2. Strictly abide by the integrity system, do not accept any form of gifts from factories, do not disclose the customer's technical documents and related requirements, and adhere to the professional bottom line;
3. In response to the existence of hidden quality problems in the factory, we need to put forward specific and implementable improvement suggestions to assist the factory to improve the level of quality management, and to realize the dual objectives of “fault-finding + problem solving”.
Fifth, the core value of the factory inspection and summarize the recommendations
The industry consensus is that good products are not inspected, but produced. The core responsibility of the factory inspection personnel is to rely on professional industry standards and rigorous work attitude, forcing factories to standardize the production process, the quality of hidden dangers nipped in the bud. Customers are willing to invest in costs to carry out in-plant inspection, the core purpose is to avoid rework, returns, claims brought about by the batch of unqualified products, which is the core value of in-plant inspection.
Executable recommendations: before the start of the work in the factory, the need for inspectors, factories, customers, three parties, clearly confirm the AQL sampling standards, key quality control points, non-conforming products processing procedures, while checking the factory ISO system certificate, equipment calibration records, from the source to avoid quality disputes at a later stage.
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