The pcb factory needs to guarantee the quality of pcb, we must understand the new and old qc seven methods. The new seven methods of management, also called the new seven tools of quality control, its role is mainly to solve some management problems with a more convenient way, compared with the original "old" quality control seven major methods, it is mainly used in In the high-level management, the old seven techniques are mainly applied in specific practical work. Therefore, the new seven methods are applied to companies with relatively strict management systems and high management standards.
First, the origin
The seven new and old tools are all summed up by the Japanese, and are used in many factories. The pcb factory is also used in a wide range. After the introduction of the old seven tools and the success of the Japanese, the Japanese introduced seven new tools in 1979. The reason why it is called "seven kinds of tools" is because the ancient Japanese warriors often carried seven kinds of weapons when they went out to fight. The so-called seven tools used seven kinds of weapons.
There are of course more than seven useful quality statistics management tools. In addition to the old and new tools, the commonly used tools are experimental design, distribution map, and shift map.
Second, the old seven tools
Qc's old seven methods refer to: checklist, layer method, Plato, causal map, scatter plot, histogram, and control map.
In a certain sense, the implementation of the seven major methods of qc, to a certain extent, indicates the advanced level of corporate management. The success or failure of these applications will become an important aspect of the company's upgrade market: almost all OEM customers will use statistical technology applications as important aspects of the audit, such as TDI, MOTOROLA and so on.
Third, the new seven tools
Qc new seven major methods refer to: relational graph method, KJ method, system graph method, matrix graph method, matrix data analysis method, PDPC method, network graph method. Relatively speaking, the promotion and application of the new seven major methods in the world is far less than the old seven methods, and has never become an important aspect of customer review.
Four old versions:
1. Check List Make a graph or a form in a simple data or easy-to-understand way. Just write the check mark and sort it out for further analysis or check-up. The purpose is to investigate the status quo.
2. Pareto Diagram According to the collected data, the items are classified according to the causes, adverse conditions, bad occurrences or types of customer complaints, safety incidents, etc., to find the project or cause with the largest ratio and sorted by size. , plus a graph of cumulative values. Used to judge the crux of the problem.
3. Character map (CharacterisTIc Diagram) When the characteristics (results) of a problem are affected by some factors (causes), these factors are sorted out into a correlated and systematic and systematic graph. Its main purpose is to clarify the causal relationship, also known as the "cause and effect diagram", which is often referred to as the "fishbone diagram" because its shape is similar to the fishbone diagram.
4. Scatter Diagram (Scatter Diagram) Corresponding data related to each other, the result is represented by the vertical axis on the square, the cause is represented by the horizontal axis, and the distribution form is represented by the point, and the corresponding data is not judged according to the shape of the analysis. Interrelationship.
5. Control Chart A diagram used to investigate whether a manufacturing process is in a steady state or to maintain a manufacturing process in a steady state. Control the product quality characteristics of the vertical axis table, and divide the process change data; the horizontal axis represents the product group number and manufacturing cycle, draw the points on the map according to the chronological order, and compare with the control limits to determine whether the product quality is stable. A graphic.
6. Histogram (Histogram) The collected data characteristic value or result value is divided into several equal intervals on a horizontal axis of a certain range, and the area in which the number of occurrences of the measured values ​​in each interval is accumulated is used in a column shape. Draw the graphics. Therefore, it is also called a column chart.
7. StrapTIficaTIon An analysis method for classifying and counting data collected by department, person, work method, equipment, location, etc. according to their common characteristics.
Five: new edition
The new seven qc tools are also very extensive in the modern pcb factory, which is what our pcb people need to know.
The new seven qc tools are: association graph method, affinity graph method (KJ method), system graph method, matrix graph method, matrix data analysis method, process decision program graph method (PDPC method), and vector line graph method. They can be applied at all stages of product development, especially for the case demonstration and preliminary design stages where it is difficult to get sufficient data. The characteristics of the seven tools of the new qc are based on graphics, suitable for sorting out the ideas of not enough systems, clarifying the complex relationships among the various elements, clearly asking questions, finding out the means and methods for solving the problems, and chronologically Sort and determine the work plan.
I. Correlation graph method In the analysis of the reasons for the low pass rate, we tried the association graph method. Because our management is not in place, the workers are not good at maintaining the machine, and because the workers are not good at the maintenance of the machine, the equipment produces more unqualified products, because the production of non-conforming products is mostly skilled workers, and the lack of training for the students. The quality inspection was not in place. Later, we increased the training of employees and the product qualification rate also rebounded. The association graph method is a method that is complicated and intertwined with reasons, results, purposes, and means. It is logically used to indicate the relationship between them and to determine the main influencing factors, also known as the relation graph method.
Second, the kj (affinity map) method kj (affinity map) method is the core of the brainstorming method, based on the results to find reasons. At a quality analysis meeting, we reviewed the reasons for the decline in the quality pass rate in the near future. Ask everyone to analyze the reasons for the decline in quality, and then propose corresponding improvement measures, because the reasons for the decline in quality are more complicated, everyone is silent, once limited the meeting to a deadlock. Later, the moderator guided everyone, everyone can put forward their own ideas, and now does not require specific analysis, just to put the ideas on record, so that the discussion of the meeting can be carried out enthusiastically. After the meeting, the organizers will analyze and analyze these issues. In this way, not only the meeting was carried out normally, but also the reasons for the deterioration of quality and improvement measures were found. The kj (affinity map) method can also be used for production efficiency and corporate financial analysis.
The kj (Affinity Graph) method was created by Japan’s Kasumi Hiroshi, and the tool of the kj analysis method is a type diagram (a type diagram is only applicable to problems that require time to solve and solve, and is not applicable to simple problems to be solved immediately). A method of comprehensively analyzing the collected data and information according to their similarity, also known as the card method.
The kj analysis method is a creative way of thinking about problems. The human brain is divided into two parts. The human thinking behavior is dominated by the left part of the brain. It is rational and not creative. If the function of the left brain is suppressed and the brain is consciously activated, the creative thinking can be carried out. The kj analysis method is based on the above principles to analyze and solve the problem.
Third, the system diagram method When planning the quality system, the most commonly used system diagram method. Our quality department is divided into several processes. Several people need to be inspected for the inspection. The training requirements of the staff are required. What kind of training should be given to them, the responsibilities of each person, the tools they use, the inspection operation book, the inspection form, and the quality. Feedback of information, etc.; process inspection, warehousing inspection and shipment inspection all require several people, the requirements of the staff to be trained, what kind of training they should be, the responsibilities of each person, the tools they use, the inspection operation book , inspection forms, feedback on quality information, etc.
The system diagram method is also called the tree diagram method. In order to achieve the purpose, the means is selected, and the previous purpose is connected with the next means. The purpose and the means are connected to each other and the graph is expanded step by step. Use it to systematically analyze the cause of the problem and determine how to solve it.
Fourth, the matrix diagram method In the analysis of the relationship between raw materials and quality, the matrix diagram method can be used. The fabric of the electric blanket has an effect on the appearance and sewing, and has no effect on safety. The pvc heating wire has a great influence on the safety of electrical appliances and has little influence on the appearance.
The matrix diagram method is to use the mathematical matrix to represent the relationship between the factors, to explore the problem and to solve the problem. It is a way of thinking and analyzing problems.
V. Matrix Data Analysis Method When analyzing the function of a product, the matrix data analysis method is commonly used. For example, the function of electric blanket is analyzed: the impact of product safety performance is 10, which has a major impact on the product; the functional impact of the product is 9 grade, which has a great impact on the product; the occasional jump of stitching is 0 grade, the product Generally no effect.
Matrix data analysis is a method to study the data processing of pairs of factors to determine the extent to which each factor affects the results. According to various factors, the degree of influence on the event can be divided into 0-10, of which “10†has the greatest impact and “0†has the same effect.
Sixth, pdpc (process, decision, program, diagram) method in the process of product layout, you can use the pdpc method, such as the arrangement of a route, what are the advantages? What are the disadvantages? What is our production efficiency and quality control level? What are the advantages of the b route? What are the disadvantages? What is our production efficiency and quality control level? According to the c route? Is there a better way? Then choose an optimal process roadmap. The pdpc method is an analysis method that performs advanced prediction and analysis on possible predicted problems to achieve an ideal state in the initial stage of system design and planning. It is also called process decision program diagram method and major accident prediction map method.
The pdpc method is not limited by human factors. It takes the actual situation as a starting point to consider what method to take, predict the possible outcomes, propose a strategy to achieve the goal, and determine the final solution to the problem.
Seven, the vector diagram method The vector diagram method is generally used in the production planning, which process we first produce, which process is produced, and the number of days they need to use. In the production planning, we must balance the production capacity of the test process and the storage time of raw materials. We use the vector diagram method to analyze the most economical and time-optimized production roadmap.
The sagittal diagram method is also called the cyber technique (pert) method, also called the key route method (cpm). It is an analytical method for developing the best schedule, finding the best route, and completing the project efficiently.
Small computer system interface (SCSI) is an independent processor standard for system level interfaces between computers and intelligent devices (hard disks, floppy drives, optical drives, printers, scanners, etc.). SCSI is an intelligent universal interface standard.
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