What is Total Quality Control

Total Quality Control (TQC) is a quality management form based on the participation of all members of the organization. Total Quality Control represents the latest stage of quality management development, originating in the United States and later being implemented in some other industrialized countries, each with its own strengths in practical application. Especially in Japan, comprehensive quality control has been implemented since the 1960s and has achieved fruitful results, attracting attention from countries around the world. Since the late 1980s, Total Quality Control (TQC) has been further expanded and deepened, gradually evolving from the early Total Quality Control (TQC) to Total Quality Management (TQM). Its meaning goes far beyond the general field of quality management and has become a comprehensive and holistic management approach and philosophy.

It has two meanings:

One is comprehensive control, which means focusing on quality and implementing full employee, full process, and all-round control;

The second is comprehensive quality, including product quality and work quality. The definition of quality in national standards is "the sum of the characteristics and features of a product, process, or service that meet specified or potential requirements (or needs)", that is, "quality" consists of two levels: one is that the product must meet the specified or potential needs, and the other is the sum of product characteristics and features. The first level reflects the objective standards of the product. The second level reflects the intrinsic elements of the product. Only products with internal elements that meet the requirements and meet the needs of users can be considered high-quality products.

In today's rapidly developing market economy, "quality first" and "survival through quality" have become an unbreakable truth. TQC is a comprehensive scientific management system that can ensure product quality. It is an integral part of modern enterprise systems and an important link in enterprise management.

The Development of Total Quality Control

In 1951, Fegenberg proposed the concept of Total Quality Control (TQC), which expanded the scope of quality assurance from manufacturing to various functions from design to sales.

In 1955, JUSE invited Professor Zhu Lan to Japan to guide TQC. Managers began to participate in quality improvement work at this time. In 1960, supervisors began to participate in quality improvement work. In 1962, grassroots workers participated in quality improvement, which became the Quality Control Circle (QCC). In 1965, company employees began to invest in quality improvement, which was actually a continuation of TQC, but the Japanese referred to it as Company Wide Quality Control (CWQC). CWQC has a characteristic in its promotion, which is the combination of guidance from vertical organizations and collaboration from horizontal functional organizations. Generally, it operates through vertical organizations, while promoting through horizontal functional committee organizations, in order to break away from traditional thinking and coordinate work. CWQC is a complete quality control system, which combines its own ideas and experiences such as "worker participation in management", "three inspection system", "three combinations", and "rationalization suggestion activities" on the basis of the original TQC to make it perfect. In the end, CWQC includes the policy management of operators, and the quality control circle is also one of them. CWQC effectively enhances the Japanese style quality management model.

In the 1980s, the manufacturing industry in the United States was impacted by Japan. In order to change its decline and enhance its competitiveness, the United States learned from Japan's CWQC practices. In 1980, NBC released an album titled 'Japan Can, Why We Can't' which sparked a wave of learning and reflection. In 1985, the US Navy Air Systems Command coined the term Total Qualitv Management (TQM) and received widespread response from various sectors. The government, business, and education sectors comprehensively promoted TQM. In this process, TQM gradually became associated with quantifying quality costs TQC、 The integration of reliability engineering and zero defect methods has formed a relatively systematic TQM system. This gives the United States an advantage in quality competition and a counter attack on the Japanese economy.

Specific measures for Total Quality Control (QTC)

The specific implementation of TQC can be summarized as follows:

1. Four stages: Plan, Do, Check, and Action. Firstly, develop a work plan, then implement it, and conduct inspections to propose improvement measures for the quality issues identified. These four stages have sequence, connection, and end-to-end connection. Each execution is a cycle called PDCA cycle, and each cycle has an improvement relative to the previous cycle.

2. Eight steps: identify problems, identify influencing factors, clarify important factors, propose improvement measures, implement measures, check the implementation status, standardize the implemented measures, and handle remaining issues.

3. Fourteen tools: During the execution and inspection phase of the plan, fourteen tools (methods) were utilized to analyze and solve problems:

Hierarchical method, Pareto chart method, causal analysis method, histogram method, control chart method, correlation analysis chart method, inspection chart method, relationship chart method, KJ method, system chart method, matrix chart method, matrix data analysis method, PDPC method, and vector line chart method. The first seven are traditional methods, while the last seven are later generated, also known as the new seven tools.

Process quality audit

What is process capability analysis

Process capability analysis is essentially the evaluation of the consistency between process capability and specified requirements through systematic analysis and research. Process capability, also known as process capability, refers to the ability to meet the processing quality requirements in the machining process. It measures the internal consistency of the machining process and the minimum fluctuation under the most stable state. When the process is in steady state, 99.73% of the quality characteristic values of the product are scattered in the interval [μ -3 σ, μ+3 σ], where μ is the overall mean of the product characteristic values and σ is the overall standard deviation of the product characteristic values. In other words, almost all product characteristic values fall within the range of 6 σ Therefore, the process capability is usually represented by 6 σ, and the smaller its value, the better.

Operation of Process Capability Analysis

Conducting process capability analysis is essentially evaluating the consistency between process capability and specified requirements through systematic analysis and research.

There are two main reasons for conducting process capability analysis. Firstly, we need to know the controlled quantity of baselines that process metrics can provide; Secondly, as our measurement plan is still quite 'immature', it is necessary to evaluate the process measurement baseline to determine whether to make changes to reflect the improvement of process capability. Based on the quantitative indicators of process capability, we can accordingly relax or narrow the control conditions of the baseline.

Process capability refers to the actual processing ability of the process to produce qualified products stably under normal 5M1E conditions. The process capability depends on the precision of machine equipment, materials, processes, process equipment, the quality of workers' work, and other technical conditions. The process capability index is represented by Cp and Cpk.

Design quality control

What is design quality control

Design control is a management behavior that analyzes, processes, judges, makes decisions, and modifies the entire technical operation process of design with the aim of ensuring that the design results meet the needs of human society.

The "Product Quality System Engineering in CIMS Environment" points out that quality control is to adopt certain methods to ensure that the quality characteristics of the product are within the prescribed standard range. It also points out that quality control in the product planning process refers to the formulation, guarantee, and control of quality performance indicators in the product requirements analysis, functional structure design, and process design processes. In addition, the ISO9000 standard provides a concise definition of quality control [2]: a part of quality management that aims to meet quality requirements.

Design quality control should run through the entire process of forming design quality, and the object of design quality control is the design process.

Object of Design Quality Control

The quality in the product design process includes two aspects, one is product quality, and the other is the quality of work in the product design process. Product quality is the core, and work quality is the guarantee of design quality. The quality control of the design process is to achieve the comprehensive goal of improving the design quality by improving the quality of these two aspects. In terms of product quality, in addition to considering the "applicability" requirements of customers, it is also necessary to fully consider the feasibility of production and manufacturing, such as the process of product structure, standardization level, production efficiency, and other factors. The previous section analyzed the quality influencing factors in the design process from five aspects: people, machines, materials, methods, and environment. Among them, the "environment" factor has been greatly improved in modern enterprises and is no longer the main influencing factor. Therefore, the objects to be controlled in design quality control are mainly people, machines, materials, and methods. The summary is as follows:

① Designers assign design tasks to designers, supervise their task completion, and promote the improvement of their overall quality.

② The control of the design process and the management of the design process should be well controlled to ensure product quality.

③ Design information refers to various file information generated during the design process, which can be divided into two categories: text documents and data files. Text documents include: design task book, contract text, technical agreement, development plan, quality plan, review records, etc; The data files include: renderings, images, 3D data, etc.

④ Choose effective design methods that are suitable for the needs of the enterprise.

Content of Design Quality Control

The design and development process of a product is an innovative process, and the quality function of this process is reflected in two aspects: one is to ensure that the product quality meets user needs; The second is to meet the requirements for subsequent production and processing. According to the quality functions of these two aspects and the requirements of ISO9000 system standards, the quality management and control work of the product design process should include the following:

① Conduct market research to determine product quality requirements;

② Pay attention to design decisions, choose reasonable development and design methods, that is, establish a scientific and reasonable design and development process, choose advanced design tools and quality design techniques;

③ Strictly follow the general rules of product development and design, scientifically and reasonably arrange the tasks and responsibilities of each design stage;

④ Do a good job in design quality planning;

⑤ In the design process, supplemented by design analysis;

⑥ Pay attention to design review and overcome design defects through early warning;

⑦ Organize the trial production, testing, and identification of products to conduct reliable design verification and confirmation.

⑧ Focus on continuous improvement of design quality, record and analyze quality issues, and promote design improvement.

The Development Trend of Design Quality Control

1. The Development Trend of Design Quality Control Research

The research and practice of "zero defect" design technology is based on the zero defect theory of quality master Clausewitz, as well as continued in-depth research on quality design technology, quality analysis methods, and quality control methods, especially the rapidly developing 6 σ design and 6 σ quality control methods in recent years. Zero defect quality is combined with the design and development process, and a zero defect product design and development strategy is proposed, which is regarded as the core strategy of the enterprise. Strive to identify defect patterns during the design phase and consider designing error prevention devices as a preferred measure to prevent defect occurrence, achieving zero defect management in the design and development process, thereby ensuring zero defects in the design process and design quality. Zero defect design quality control should be an important trend in the development of design quality control.

2. The Development Trend of Information Management for Design Quality Control

At present, research on the application of information technology mainly focuses on the development of quality data management information systems, and there is little dedicated research on the application of design quality control information systems. Therefore, the development trend of information management for design quality control in the future will be how to develop an effective information system that links advanced and feasible design quality control theories with the implementation of design quality control systems, in order to effectively control the design process and improve design quality.

3. Universal design of design quality control system

While developing and designing quality control information systems, attention should be paid to the universal design and specialized application of the system. That is to say, the developed system can be suitable for any enterprise application, and the enterprise only needs to define its own design process when applying. The development of a universal system can improve the effectiveness of the system, reduce the cost of specialized development, and make it easier to promote and use.

4. Organic integration with quality information system

With the development of information technology, more and more quality information systems are being applied by enterprises. Due to the large amount of data information generated by each system, excessive information is not conducive to making effective decisions for enterprises. Therefore, enterprises will inevitably demand information system integration, and the organic integration of design quality control systems with various quality information systems will also become an important development trend.

Design Quality Review

What is design quality review

Design quality review is the application of early warning and risk prevention principles to concentrate various experiences on design and development, provide consultation for design decisions, and achieve the goal of discovering and remedying design and development defects, ensuring product usability and economy.

Program quality review is usually conducted from the perspective of developers and is directly related to development technology. It is a review activity that focuses on the structure of the software itself, the interface with the operating environment, and the impact of changes.

The review content of design quality review

The object of design quality review is the software requirement specification and data requirement specification generated during the requirements analysis stage, as well as the software outline design specification generated during the software outline design stage. Usually, evaluation needs to be conducted from the following aspects:

(1) Evaluate whether the software specifications meet the user's requirements, that is, whether the overall design concept and policy are correct, and whether the requirement specifications have been approved by the user or higher-level authorities of the unit; Is the requirement specification consistent with the software's outline design specification.

(2) Evaluate reliability, that is, whether it can avoid failures caused by input anomalies (errors or overload, etc.), hardware failures, and software failures. Once they occur, alternative or recovery measures should be taken in a timely manner.

(3) Review the implementation of confidentiality measures, that is, whether to provide checks on the eligibility to use the system, the eligibility to use specific data, and the eligibility to use special functions. After discovering violations of eligibility, whether to report relevant information to the system management personnel, and whether to provide encryption functions for important data within the system.

(4) Review the implementation of operational characteristics, including the appropriateness of operational commands and information, the appropriateness of input data and control statements, the appropriateness of output data, and the appropriateness of response time.

(5) Review the performance implementation status.

(6) Review whether the software has modifiability, expandability, interchangeability, and portability.

(7) Review whether the software has testability.

(8) Review whether the software has reusability.

Personnel responsible for design quality review

The personnel participating in the design quality review are mainly qualified and capable individuals from various aspects who are not directly involved in the design and do not bear the responsibility for design quality. The reviewers involve functional departments such as procurement, manufacturing, service, sales, inspection, testing, reliability, quality assurance, and customer representatives. The reviewers formulate based on the review content and requirements of the design quality review stage.