Content Introduction
1 Basic Principles of Quality Control
One of the main tasks of quality management is to collect data and organize data, find out the rules of fluctuations, control normal fluctuations to a minimum, and eliminate abnormal fluctuations caused by systemic reasons. Compare the actually measured quality characteristics with relevant standards, and take corresponding measures to correct the differences or abnormal phenomena, so that the process is in a control state. This process is called quality control. Quality control can be roughly divided into 7 steps:
(1) Select the control object;
(2) Select the quality characteristic value that needs to be monitored;
(3) Determine the specifications and explain the quality characteristics in detail;
(4) Select the instrument that can accurately measure the characteristic worth monitoring, or make a self-made test method;
(5) Conduct actual tests and keep data records;
(6) Analyze the reasons for the differences between reality and specifications;
(7) Take corresponding corrective measures.
After corresponding corrective measures are taken, the process must still be monitored and the process must be maintained at a new level of control. Once new influencing factors appear, the data analysis causes are also needed to be measured and analyzed for correction. Therefore, these 7 steps form a closed process called the "feedback loop". This has something in common with MAIC in the 6Sigma quality breakthrough mode.
Among the above seven steps, there are two most important points:
(1) Design of quality control system;
(2) Selection of quality control technology.
2 Quality Control System Design
When performing quality control, decisions need to be made on the process, quality inspection points, inspection personnel, measurement types and quantity that need to be controlled. After these decisions are completed, a complete quality control system is formed.
1. Process analysis
All quality management work must start from the process itself. Before quality control is carried out, the relevant process of producing a certain product or service must be analyzed. A large process may include many small processes that are described and decomposed by using flowchart analysis methods to determine the key links that affect the quality of products or services.
2. Quality detection point determination
After determining each process that needs to be controlled, you must find the key points that need to be measured or tested in each process. There may be many inspection points in a process, but each inspection will increase the cost of the product or service, so inspections must be carried out where quality problems are most likely to occur. Typical testing points include:
(1) Inspection of purchased raw materials or service before production. In order to ensure the smooth progress of the production process, the quality of raw materials or services must be ensured through inspection. Of course, this inspection can be exempted if the supplier has a quality certification certificate. In addition, in JIT (on-time production), it is not recommended to inspect purchased parts, and it is believed that this process does not increase value and is a "waste".
(2) Product inspection during production: Typical in-production inspection is before an irreversible operation process or before a high value-added operation. Because once these operations are carried out, they will seriously affect the quality and cause great losses. For example, before ceramic sintering, inspection is required. Because once it is sintered, the unqualified products can only be discarded or treated as defective products. For example, the product also needs to be inspected before electroplating or paint to avoid missing
traps being covered. The inspection of these operations can be carried out by the operator himself to inspect the product. Inspection in production can also determine whether the process is in a controlled state. If the inspection results show that the quality fluctuates greatly, timely measures need to be taken to correct it.
(3) Inspection of finished products after production.In order to correct product defects before delivery to customers, needs to be inspected before product is put into the warehouse or sent.
3. Inspection method
Next, we need to determine what type of inspection method should be used in each quality control point . Inspection methods are divided into: counting inspection and metrological inspection. Counting inspection is to test discrete variables such as defect number and failure rate; metrology inspection is to measure the continuous variable such as length, height, weight, and strength. In quality control during production, the problem of what type of control chart is used: the counting control chart is used for discrete variables, and the continuous variables are used for metrological control chart.
4. There are two ways to determine the number of tests: full inspection and sampling inspection. The guiding principle for determining the number of inspections is to compare the losses caused by unqualified frequency with inspection costs. Assuming that there is a batch of 500 units of products, the product failure rate is 2%, and the maintenance fee, compensation fee and other costs caused by each unqualified product are 100 yuan, then if this batch of products is not inspected, the total loss is 100*10=1,000 yuan. If the inspection fee for this batch of products is less than 1,000 yuan, it should be fully inspected. Of course, in addition to cost factors, other factors must be considered. If a product involving personal safety is involved, 100% inspection is required. Sampling tests are used for destructive tests.
5. The determination of inspectors
can adopt the principle of combining operating workers and full-time inspectors. In 6Sigma management, most inspection tasks are usually completed by the operator.
3 Quality control technology
Quality control technology includes two categories: sampling inspection and process quality control.
sampling inspection usually occurs before production or after production inspection of finished products. Decide whether to accept the batch of raw materials or products based on the quality inspection results of the random samples. Process quality control refers to the inspection of random samples of products in the production process to determine whether the process is produced within predetermined standards. Sampling inspection is used for procurement or acceptance, while process quality control is used in various forms of production processes.
Section 2 Process quality control technology
Since Hot Hart proposed the control chart in 1924, after the development of nearly 80th century, process quality control technology has been widely used in quality management, and many new methods have been continuously produced in practice. Such as the "seven QC tools" such as histograms, related diagrams, arrangement diagrams, control diagrams and causal diagrams, and the "seven new QC tools" such as the "seven QC tools" such as the correlation diagrams and system diagrams. By applying these methods, we can systematically collect various data related to the product from the frequently changing production process, and use statistical methods to organize, process and analyze the data, and then draw various charts to find the rules of quality changes, and achieve quality control. Ishikawa once said that 95% of the quality problems in an enterprise can be solved through the use of these tools by all the enterprise personnel. Whether it is ISO9000 or the 6Sigma quality management theory that has been very popular in recent years, they emphasize these
applications based on statistical quality control technology. Therefore, to truly improve product quality, companies, from leaders to employees, must master quality control technology and apply it in practice.
Inspector Training Materials 1
Part 1 The basic requirements of product inspection work Product quality is the life of an enterprise and the fundamental guarantee for enterprises to win in competition and seek their own development. In order to ensure product quality, we must first have a certain understanding of the product and quality, and at the same time understand the basic requirements of the inspection work in order to do a good job in inspection work.
Section 1 Product and its quality characteristics
1 The meaning and classification of the product
1 The meaning of the product process or the result of the service, it can include services, hardware, process materials, software; and combinations thereof.They can be tangible or intangible, but the most common ones exist are the combination of tangible and intangible between the two.
2 Product classification We classify the above four product types, referring to hardware, software and process materials as tangible products, and treating services as intangible products. The basis is that although hardware, software, and process materials are inevitably content of intangible services, they are still tangible and perceptible material products in essence. Therefore, we call them tangible products, that is, what we usually call products, and services are usually manifested as intangible products produced or activities related to the production process activities of tangible products, reflecting intangible characteristics. 2. Quality characteristics of the product
1 The definition of quality reflects the sum of characteristics of the entity's ability to meet explicit or implicit needs. That is the value of the product. In layman's terms, it is the natural attributes that products can meet the different needs of people (including society and individuals). The essence is an attribute in which objective things have a certain ability. The natural attributes of products distinguish different uses of products and meet different needs of people to varying degrees.
1.1 Clearly need: In the contract environment, the supply and demand parties make clear provisions through specific contracts.
1.2 Implicit needs: refer to the user and society's expectations for product performance, as well as recognized and self-evident, demands for specified performance.
2 The quality characteristics of the product mainly include the following aspects:
2.1 Performance: The technical characteristics that the product has to meet the purpose of use.
2.2 Lifetime
: The total working time of the product completing the specified functions under the specified conditions.
2.3 Reliability: The ability of the product to complete the specified functions within the specified time and under the specified conditions.
2.4 Safety: The risk of injury (referring to a person) or damage is limited to an acceptable level.
2.5 Economy: The cost of the product from design and manufacturing to the entire product service life cycle is the smallest.
2.6 Marketability: The product can be sold on the market, thus achieving its value. Generally, the quality characteristics of a product can also be divided into true quality characteristics and substitute quality characteristics .
a. True quality characteristics refer to quality characteristics that directly reflect customers' expectations or requirements for the product.
b. Substitute quality characteristics refer to the fact that in order to meet customer expectations, enterprises must formulate corresponding standards and requirements, determine some parameters and data, and indirectly reflect the true quality characteristics.
3 Quality characteristics of service
3.1 Functionality: refers to the performance and role played by completing a certain service.
3.2 Economy: The reasonableness of the cost of customers in order to obtain different services.
3.3 Security: The ability to ensure that customers' life, body and spirit are not harmed and property is not lost during the service process.
3.4 Timeliness: The ability of service to meet customer needs in time, including timely, accuracy and time-saving.
3.5 Comfort: The comfort level of the service process is met under the premise of meeting the previous four points.
3.6 Civilization: the degree to which customers meet their spiritual needs during the process of receiving services. In short, the quality characteristics of service emphasize timeliness, perfection, accuracy and friendliness. It can also be divided into true quality characteristics and substitute quality characteristics. The former refers to the degree of satisfaction, while the latter is a provision for the former. However, whether it is the former or the latter, it should be qualitative as much as possible. This is an objective requirement for achieving effective quality control and a basis for measuring quality status.
Inspector Training Materials 2
Section 2 Quality Inspection Quality inspection is an integral part of production activities. Its purpose is to verify whether the quality characteristics of the product meet the requirements according to the standards, so as to eliminate those products that do not meet the requirements and ensure that the product quality meets the technical requirements specified in the standards. Therefore, quality inspection is an important part of enterprise management work and an indispensable part of total quality management . 1 Overview
1 Definition Quality inspection is an activity that performs on one or more characteristics of an entity, such as measurement, inspection, test and measurement, compares results with regulations, and determines the eligibility of each characteristic.
2 The task implements the "quality first" policy, and uses advanced scientific testing methods to inspect and check all links such as raw materials and components entering the factory, production, storage, product factory, after-sales service, etc., in accordance with national laws and regulations, relevant documents and technical standards issued by competent departments and relevant technical documents, and adopts advanced scientific testing methods to conduct inspections and checks, supervise and inspect all links, and resolutely implement the national regulations on the "five prohibitions".
3 The principle of quality inspection is mainly prevention, actively preventing and strict control, full-time inspection as the main focus, and full-time inspection with mass inspection. 2. Work content (i.e. work steps) Quality inspection is a process, which generally includes the following steps:
1 Clarify quality requirements Clear inspection items and various
quality requirements according to product technical standards. In the case of sampling inspection, it is also necessary to clarify what kind of sampling plan is used to enable the inspector and operator to clarify what is a qualified product or a qualified product and what is a unqualified product or a failure. Clarify the basis for determining whether the product is qualified or not.
2 The measurement test stipulates appropriate methods and means to detect the product to obtain the quality characteristic value and results.
3 Comparison Compare the data obtained from the test with the quality requirements to determine whether it meets the quality requirements.
4 Determination Based on the comparison results, it is determined that a single product is a qualified product or a failed product, and a batch of products is a qualified product or a failed product.
5 Processing According to the judgment results, corresponding treatments will be made for qualified or unqualified products according to regulations.
5.1 Release a single product that is qualified, mark, isolate, store and dispose of unqualified products.
5.2 Decides for acceptance, rejection, screening, re-inspection, etc. for batch products.
6 Feedback record of the measured data, after sorting, statistics, calculation and analysis, quality information feedback to relevant leaders and departments in accordance with prescribed procedures, so as to grasp the current product quality status and correctly evaluate the product quality level so that relevant departments can improve quality. 3. Job functions
1 The guaranteed function is the gatekeeping function. Through the inspection, identification and sorting of raw materials, semi-finished products and finished products, unqualified products are eliminated, and whether the product or the batch of products is qualified to be accepted, ensuring that unqualified raw materials are not invested, unqualified semi-finished products are not transferred to the next process, and unqualified finished products are not left the factory.
2 The function of prevention can detect problems early through inspection, analyze the causes and promptly eliminate them, prevent or reduce the occurrence of unqualified projects and unqualified occurrences.
3 Functions of supervision The quality inspection department not only inspects direct products in accordance with the provisions of quality regulations, inspection systems and documents, but also ensures the conditions for production quality, such as whether people, machines, materials, laws, environments, process disciplines, etc. comply with regulations. The function of the report records the data and information collected during inspection, analyzes and evaluates, and reports to relevant departments in a timely manner to provide a basis for improving design, strengthening management, and improving quality.
Inspector Training Materials 3
4 Classification of quality inspection
1 According to the number of inspections
1.1 Full inspection
Complete inspection (also known as 100% inspection or product screening) It is the method to conduct all inspections on a batch of products. Generally speaking, if the sampling inspection shows that a batch of products has exceeded the allowed unqualified level, the inspection will be fully inspected as 100%.
1.2 Sampling inspection
1.2.1 Meaning: Sampling inspection is to randomly select a certain number of samples from a batch of products, and then judge whether the batch of products is qualified based on certain judgment standards.
1.2.2 Scope of application:
a. Inspection of semi-finished products and finished products with large batches, high degree of automation, and relatively stable product quality.
b. Bulk purchases of outsourced parts, outsourced parts or products with destructive inspection, etc.
1.2.3 Prerequisite: The production process of the product is stable.
1.2.4 Sampling inspection is unreasonable because it has the same possibility of receiving products with different actual quality. Therefore, the appropriate sampling inspection should be selected for sampling inspection, rather than simply using percentage sampling.
1.3 Inspection-free and inspection-free means that if a qualified unit can obtain reliability data that has been tested by
0, it does not require inspection.
2 is divided according to the order of production process, that is, according to the different stages in the entire production process of the enterprise, it can be divided into:
2.1.1.1.1. Meaning: Also called factory inspection, it refers to the storage acceptance inspection of purchased raw materials, purchased parts and outsourced parts, and other materials, which are carried out before the purchase.
2.1.2 Purpose: Ensure product quality and normal production.
2.1.3 Method: two types: first batch sample inspection and batch purchase inspection.
2.1.3.1 The first batch of sample inspection Meaning: refers to the inspection of samples from the supply unit. Function: a. Quality certification of sub-suppliers;
b. Review whether sub-suppliers have quality assurance capabilities;
c. Provide a basis for measuring the quality level of future batch purchases.
2.1.3.2 Batch purchase inspection Meaning: refers to the inspection of batches of goods during normal delivery by the sub-supplier. Method: divided into three categories: ABC, Class A key - must-check Class B important - random inspection C general - exemption of inspection: a. Prevent unqualified raw materials (outsourced parts, purchased parts) and other materials from entering the production process;
b. Provides necessary conditions for stabilizing normal production order and ensuring product quality;
c. An important means to assess the continuity of the quality assurance capacity of supplier units.
2.2 Process inspection
2.2.1 Meaning: refers to the inspection performed after a certain process is completed.
2.2.2 Purpose: Prevent unqualified semi-finished products from flowing into the next process.
2.2.3 Method: three types: first-piece inspection, circuit inspection and completion inspection.
2.2.3.1 First piece inspection Meaning: refers to the inspection of the first or first few products manufactured at the beginning of production or after the process factors are adjusted, that is, the first piece inspection must be strictly carried out before any changes occur in the equipment or manufacturing process, and before each work shift begins processing. Purpose: To prevent product finished products from being out of reach, counter-repair and scrapping. Method: Adopt the first three-inspection system—worker self-inspection, squad leader re-inspection, inspector inspection.
2.2.3.2 Circuit Inspection Meaning: refers to the inspector inspecting the product quality of the relevant process at a certain time interval or the quantity interval of processed products at the production site; for unstable processes, a regular sampling inspection is carried out during the batch production process.Method: Use inspection routes and procedures to prepare inspections, and inspect relevant processes at certain time intervals to play the inspection function.
2.2.3.3 Complete inspection Meaning: Inspection of the last products made in a batch of products, which is conducive to a comprehensive grasp of the situation. Purpose: Verify whether the process meets the prescribed requirements. Method: Set necessary inspection points, such as quality control points, in appropriate processes and stations in the process flow, according to the importance of product characteristics and the complexity of inspection items.
2.3 Finished product inspection
2.3.1 Meaning: that is, final inspection and factory inspection are quality inspections of finished products.
2.3.2 Content: Product performance, security, appearance.
2.3.3 Purpose: To ensure that unqualified finished products do not leave the factory and unqualified finished products do not enter the warehouse.
Inspector Training Materials 4-6
3 According to the inspection method, it can be divided into
3.1 Sensory inspection: Sensory inspection is functional inspection. It refers to an inspection method that evaluates and determines the quality of product
by the human sensory organs (visual, hearing, smell, taste, touch, etc.) to evaluate and determine the quality of product
.
3.2 Architecture Inspection (physical and chemical inspection): Utility inspection is a method to detect product quality by using physical and chemical means, using metrological instruments and physical and chemical analysis methods.
4 According to the inspector, the quality of manufacturing mainly depends on the technical level, sense of responsibility and quality awareness of each operator. Therefore, in addition to establishing a full-time inspector team, enterprises must also widely organize operators to participate in the inspection, a "three-inspection system" that combines actual operators and inspectors.
4.1 Self-inspection Self-inspection refers to the operator's self-examination of the products he has processed, timely eliminating abnormal situations, and preventing the occurrence of unqualified products.
4.2 Mutual inspection
4.2.1 Meaning: Mutual inspection refers to the mutual inspection of processed products conducted by operators in accordance with technical standards and document requirements to achieve mutual supervision. It is formed on the basis of self-test.
4.2.2 Format: mutual inspections between operators of this team; handover inspections between upper and lower processes; team leader (team quality staff) conducts random inspections on the processing products of operators of this team, etc.
4.3 Special inspection
4.3.1 Meaning: Special inspection refers to the special inspection by a full-time inspector to conduct special inspection of product quality.
4.3.2 Scope of application: General enterprises conduct inspections of raw materials, semi-finished products and finished products mainly focus on full-time inspections. Special inspection workers can also be installed for key processes and quality control points to conduct inspection; while general processes in the production process mainly involve operators' self-inspection and mutual inspection.
5 According to the inspection location, it can be divided into fixed inspection, circuit inspection and dispatch inspection.
6 According to the inspection content, it can be divided into qualified inspection, performance test and durability test.
7 According to the purpose of the inspection, it can be divided into inspection of acceptance properties and inspection of monitoring properties.
8 According to whether the product can be used after inspection, it can be divided into destructive tests and non-destructive tests. 5. Quality inspection personnel
1 Basic requirements for quality inspection personnel Quality inspection personnel are the main providers of internal quality information of the enterprise and are directly responsible for ensuring the quality of the factory products. Therefore, the quality of the inspector affects the quality of the product to a certain extent. Therefore, the inspector should have the following basic requirements:
1.1 Have a strong sense of quality, establish the idea of "quality first" and "quality is the life of the enterprise", and be able to adhere to principles, seek truth from facts, act conscientiously, strictly and accurately, and make scientific and fair judgments when encountering things.
1.2 Have certain cultural and scientific knowledge. Have strong analysis and judgment skills.
1.3 Have technical skills that are suitable for the inspection tasks they undertake; be familiar with the basic theoretical knowledge of the inspection processes they undertake; have a deeper understanding of the quality requirements of the upper and lower processes and the entire product than the production workers.
1.4 You should be familiar with quality standards, be able to correctly use relevant measuring instruments, conduct inspections in accordance with quality standards, and provide inspection data and reports correctly.
1.5 You must undergo professional training and pass the assessment before you can take up your post and independently present the test report.
1.6 has good physical fitness and can adapt to inspection work.
Inspector Training Materials 5
2 The relationship between inspectors and operators
Inspectors and operators should trust each other and cooperate closely. Only by widely mobilizing and driving operators to pay attention to product quality, regard improving product quality as their own glorious responsibilities, conduct self-inspection according to the quality standards of the process, and implement a system that combines professional inspection with production workers' self-inspection and mutual inspection, can the quality inspection work be further carried out.
For inspectors, they must be impartial and conduct inspections strictly in accordance with the inspection instructions. We must fully realize that the role of inspection is not only to control product quality, but more importantly, to provide operators with appropriate information to help them discover the causes of abnormalities in a timely manner and to guide them to take effective measures as soon as possible. Therefore, inspectors should be good “three members” and insist on achieving “three satisfactions”.
"three members" are product quality inspectors, quality first promoters and production technology counselors.
"Three Satisfactions" means that the attitude of production service satisfies the operator, the inspected products satisfies the next process, and the quality of the products left-handed is satisfies the user.
For operators, we must correctly understand the role of the inspector. Inspection helps oneself ensure and improve product quality, not just to grasp problems. Therefore, every operator should truthfully reflect the product quality status, especially when the product is qualified, he should immediately report it to the inspector and seek the inspector's help and guidance.
6. Unqualified control and corrective measures
1. Control measures for unqualified products:
Control measures for unqualified products refer to measures taken when materials, parts or finished products cannot meet or may not meet the specified requirements, including identification, isolation, review, disposal and taking corrective measures to prevent recurrence?
2. Treatment measures:
2.1 Identification: If unqualified products are found, they should be marked immediately;
2.2 Isolation: Through identification, the unqualified products are isolated from the qualified products and placed in a designated isolation area or container.
2.3 Review: Designate relevant departments to conduct review to determine whether concessions will be accepted by or re-repair, rework, downgrade, or scrap.
2.4 Disposal: Deal with the unqualified products immediately according to the review decision, including re-repair, downgrade, scrapping, franchise (or concession), and rework.
should be clear that the disposal conclusion is only valid for the batch and cannot be used as the basis for future verification or acceptance.
2.5 Preventive measures: Take measures to prevent misuse and installation of unqualified products, such as isolation, recovery, etc.
2.6 Prevent recurrence: strive to achieve the "three no waiver", that is, the reasons are not identified, the responsibilities are unclear, and the measures are not implemented.
The treatment measures for individual unqualified products are: recording, identification, and isolation.
3 Corrective Actions
Corrective Actions are measures taken to prevent the occurrence of unqualified products, defects or other undesirable situations that have occurred again and eliminate the causes. To this end, we must focus on the following seven links: allocation of responsibilities; severity evaluation; investigation of possible causes; analysis of problems; elimination of causes; process control; permanent changes.
Inspector Training Materials 6
Section 3 Quality Control Points
1 Concept and Characteristics of Quality Control Points
1.1 Concept: refers to an object or entity that needs to be controlled in the process of quality activities.
1.2 Features: It has dynamic characteristics. That is, as the process progresses, its settings are not permanently unchanged. Listed as: The quality unstable factors in a certain link are effectively controlled. If they are in a stable state, the quality control point can be cancelled; and when other links and factors rise to become the main contradiction, a new quality control point needs to be set up.
2 Principles and steps for setting quality
control points
2.1 Setting principles:
2.1.1 Control points should be set for key quality characteristics, key components or important influencing factors that have a serious impact on the applicability of the product (performance, accuracy, life, reliability, safety, etc.).
2.1.2 Control points should be set for key quality characteristics and components that have strict requirements on the process and have a serious impact on the work of the next process.
2.1.3 For projects with unstable quality and unqualified products, control points should be established.
2.1.4 Control points should be established for important bad projects that are reported by users.
2.1.5 Control points should be established for key projects that may have a significant impact on production arrangements in scarce materials.
In short, a product should be equipped with multiple control points during the manufacturing process, which depends on the complexity of the product process, as well as the requirements for characteristic classification and defect classification marked on the technical documents.
2.2 Steps to set control points:
2.2.1 Combined with the quality system file , clarify the quality characteristics and leading factors that require special control in key links and parts according to the quality links.
2.2.2 The design, process and technology departments determine the quality control points that must be specially managed by the department, prepare a detailed list of quality control points, and include them in the quality system document after approval.
2.2.3 Prepare a flow chart of quality control points and set quality control points based on this.
2.2.4 Prepare quality control point operation instructions, including process operation cards, self-test forms and operation instructions.
2.2.5 Prepare quality control point management measures.
2.2.6 formal acceptance quality control point. The documents prepared must be combined with the quality system documents and approved to be formally included in the quality system for effective operation.
3 Implement
Prepare a detailed list of quality control points, a flow chart of quality control points and work instructions, as well as division of labor and coordination of functional departments according to the steps.
4 Clarify responsibilities
After the quality control point is implemented in a specific job position, the operators and inspectors must clarify the responsibilities they should perform.
4.1 Responsibilities of operators
4.1.1 Clearly and accurately grasp the quality requirements and key difficulties of the quality control points of this process.
4.1.2 Be familiar with the prescribed procedures of the work instructions and strictly follow their requirements.
4.1.3 Master the necessary inspection methods and methods, and strictly check according to the requirements of relevant technical documents.
4.1.4 Understand the importance of this process and know the degree of impact on the next process and the comprehensive.
4.2 Responsibilities of inspectors
4.2.1 Clarify the leading factors and relevant parameters that affect quality control points and track and test them.
4.2.2 Clarify the inspection focus of the process in the quality control points and cooperate with the operator to conduct inspections and records.
4.2.3 Be familiar with the quality requirements and inspection methods of quality control points, and conduct inspection according to the knowledge book.
4.2.4 If a problem is found, analyze the cause in a timely manner and assist the operator in solving the quality problems.
Inspector Training Materials 7
5 In addition to strictly following the relevant technical documents, the control and processing of quality control points of creative work requires very high skills and rich experience. Therefore, creative work must be done to deal with key quality issues well.
5.1 Operators should do:
5.1.1 Learn the basic knowledge of comprehensive quality management, master the necessary operating methods and means, and make accurate and flexible use.
5.1.2 Record number
is accurate, statistical analysis is correct, and bias caused by forged data is prevented.
5.1.3 If deviations or abnormalities are found during the operation, the cause should be analyzed immediately and measures should be taken to correct it.
5.1.4 Keep abreast of necessary information in a timely manner, and not only communicate information with relevant personnel, so as to deal with quality issues in a timely and better manner.
5.2 Inspectors should do:
5.2.1 Learn the basic knowledge of total quality management well, master theories and methods of quality inspection, and make accurate and flexible application.
5.2.2 Familiar with the charts, methods and functions used in quality control points, and help operators solve incorrect detection and records through inspection.
5.2.3 During inspection, you should work closely with the operator to help the workers strictly implement the relevant technical documents of the quality control points.
5.2.4 Master the necessary information and communicate and communicate in a timely manner.
Section 4 Sampling Inspection 1 Concept
1 Concept: It is to randomly select a product from a batch of products submitted for inspection according to the pre-specified sampling method , and randomly select a product as a sample from a batch of products submitted for inspection, inspect the samples one by one, and make a judgment on whether the entire batch of products is qualified based on the results.
2 Scope of application: destructive inspection and acceptance; inspection and acceptance with large batches of products and not very high quality requirements, and the measurement objects are continuous inspection and acceptance; hope to save inspection costs; inspection items are large; hope to strengthen the quality of the supplier.
3 Issues to be noted:
3.1 Sampling can only relatively reflect the quality of the product, and the unqualification rate of the sample cannot be equal to the unqualification rate of the entire batch of products.
3.2 Product batches that are judged to be qualified by sampling inspection do not mean that every product in the batch is qualified; vice versa.
3.3 Not any sampling inspection can achieve the purpose of correctly judging the quality of the entire batch of products.
4 Advantages: Save inspection costs; ensure product quality, strengthen quality management; urge sub-suppliers to provide high-quality products. 2. Conditions for reasonable sampling schemes. When the product quality is good, there is a high probability of receiving; when the product quality decreases, the probability of receiving decreases rapidly; when the product quality is poor, there is a high probability of rejection. 3. Classification of sampling schemes
1 According to the degree of guaranteeing product quality indicators, it can be divided into: counting sampling inspection and metrological sampling inspection.
2 According to the degree of product quality assurance, it can be divided into: standard sampling inspection, select sampling inspection and adjusting sampling inspection.
3 According to the purpose of sampling inspection, it can be divided into batch-by-batch sampling inspection, quality supervision sampling inspection, fixed sampling inspection, and production process quality control sampling inspection.
4 Classified by the number of inspections: one sampling inspection, second sampling inspection, multiple sampling inspection, and sequential sampling inspection.
Inspector Training Materials 8
4 Implementation procedures for adjusting counting and sampling inspection
1 Determine product quality standards
Clearly distinguish the boundary between qualified and unqualified, and divide the categories of unqualified products.
2 Determine the inspection level. There are three general inspection levels: Ⅰ, Ⅱ, Ⅲ and four special inspection levels: S—1, S—2, S—3, S—4.
2.1 Three general inspection levels
a No special requirements, general inspection level I is adopted.
b When it is allowed to reduce the discriminatory ability of the sampling scheme, general examination level II can be used.
c When it is necessary to improve the identification ability of the sampling plan, general examination level III can be used.
check level III is higher than II, and Ⅱ is higher than I.
2
.2 Four special inspection levels
. In the case of high product and inspection costs, if you would rather increase the risk of the user and reduce the sample size, you would use the special inspection level. Therefore, this level of inspection generally requires that sufficient technical and quality data have been accumulated in the past. After analysis, it is believed that the mass fluctuations between individuals in the batch are small before they can be used.
3 Specifies the AQL value (unit in %)
is generally averaged based on the historical data estimation process, and this value or slightly smaller value is determined as AQL.
AQL value refers to a boundary value specified to balance the quality of a series of submitted inspection batches.
4 Determine the sampling plan type
generally only consider choosing a one-time sampling plan or a secondary sampling plan.
5 Sample size font code search.
6 Sampling inspection scheme search.
5 Sampling inspection program diagram
GB2828—87 Adjusted counting sampling inspection
Sample Large Size Code
Batch range Special inspection level General inspection level
(thumb)
Section 5 Quality improvement
1 The meaning and significance of quality improvement
1. The meaning of quality improvement
provides more benefits to the organization and its customers, and various measures taken throughout the organization to improve the efficiency and efficiency of activities and processes. To understand this concept, we need to clarify the following points:
a Quality improvement is achieved through the improvement process.
b Quality improvement is a continuous activity.
c Quality improvements include defensive improvements and offensive improvements.
d Measures for quality improvement include preventive measures and corrective measures.
e The motivation for quality improvement comes from the need to continuously improve quality and customer satisfaction.
2. The significance of quality improvement
Quality improvement is of great significance to improving product quality, reducing costs, and increasing economic benefits. It is cute as follows:
a Improves the excellent yield rate and increases revenue for enterprises.
b Improve quality and reputation, improve relationships with customers, and increase sales.
c Reduce waste defective products and increase production.
d Reduce rework and improve production efficiency.
e Reduce inspection, screening and testing costs.
f Accelerate the development of new products and new technologies and promote technological progress.
g Use funds reasonably and give full play to the potential of the enterprise.
h Cultivate the spirit of continuous progress and reform, and improve the quality of personnel.
i Improve quality functions, improve quality assurance capabilities, etc.
3. The goal of quality improvement
The goal of quality improvement is to reduce quality loss, and reduce quality loss through continuous improvement process, thereby achieving better results and higher efficiency.
Inspector Training Materials 9
2 Methods for quality improvement
1. Basic Methods for Quality Improvement - PDCA Loop
"Plan (PAN)-Execution (DO)-Check (CHECK)-Summary (ACTTON)" Loop, referred to as PDCA Loop for short. It reflects the four stages that quality improvement and other management work must go through? These four stages are constantly circulating.
2. Basic work content of the four stages of PDCA
a Stage P: With the purpose of improving quality and reducing consumption, through analysis and diagnosis, the improvement goals are formulated, and specific measures and methods to achieve these goals are determined.
b Stage D: According to the planned content, overcome various resistances and do it in a solid manner to achieve the goal of quality improvement.
c Stage C: Compare the planning requirements, check and verify the effect of execution, and promptly discover experiences and problems in the planning process.
d Stage A: Acknowledge the experience of successful
, and set it into standards, regulations, and systems to consolidate achievements and overcome shortcomings.
3. PDCA eight specific working steps
a Analyze the current situation and find out the existing and major quality problems;
b Diagnostic analysis of various influencing factors that cause quality problems;
c Find out the main factors that affect quality;
d Formulate measures, propose improvement plans, and expect their effects;
e Execute measures according to the established plan;
f According to the requirements of the improvement plan, check and verify the actual implementation results to see if the expected results have been achieved;
g summarizes the results of the inspection, and incorporate the successful experience and the lessons of failure into relevant standards, systems and regulations to consolidate the achievements that have been obtained and prevent repeated problems;
h proposes problems that have not yet been resolved in this cycle.
4. Features of PDCA
a Large ring and small rings are connected to each other, promoting each other.
b Continuously rising.
c To promote the PDCA cycle, the key lies in the "summary" stage.
Part 2 Quality statistics technology and common tools
First energy saving Basic knowledge of quality statistics
1 Quality statistics
1.1 Definition of quality statistics, quality statistics is a science. It is a process of collecting, regulating and analyzing quality data and related situations in the production process using scientific theories and methods. It is an important part of the economic activities of enterprises.
1.2 Contents of quality statistics: statistical work, statistical data, statistics theories and methods.
1.3 Principles of quality statistics: seek truth from facts.
Guess you like
Get method: Download address t.zsxq.com/04bu7a2rB
Project quality management focuses on the sharing of enterprise project management, quality management knowledge and information!
