KR100739081B1 - Method for analyzing a failure mechanism - Google Patents

Abstract

The present invention relates to a method for analyzing a failure mechanism implemented to prevent a failure in a product in the development stage of a product (system), and in particular, a method for effectively identifying the cause and effect mechanism of a predicted failure mode. The present invention relates to an analytical method that improves the reliability of a developed product and further accumulates and manages analysis results so that knowledge such as personal experience and know-how related to the failure of the target product can be recycled as the organization's knowledge. The present invention provides a method for analyzing a failure mechanism, comprising: creating a failure mode mechanism diagram hierarchically displaying a cause of an analysis target failure mode as a causal relationship between items, failure factors, and failure modes; Converting the failure mode mechanism into structured knowledge, accumulating the converted knowledge in a storage device, searching for another analysis failure mode by using the accumulated knowledge, and searching for the analyzed failure mode Automatically generating a failure mode mechanism for the.

Failure Mode, Failure Factors, Items, Targets, Failures, Mechanisms

Description

How to Analyze Failure Mechanisms {METHOD FOR ANALYZING A FAILURE MECHANISM}

1 is a flowchart of a method of analyzing a failure mechanism according to the present invention;

2 is a structural diagram of an example of a type A failure mode mechanism according to the present invention;

3 is a flowchart of a method of creating a type A failure mode mechanism according to the present invention;

4 is a diagram showing an example of a type A failure mode mechanism.

5 is a structural diagram of an example of a type B failure mode mechanism according to the present invention;

6 is a flowchart of a method of creating a type B failure mode mechanism according to the present invention;

7 is a diagram showing an example of converting the failure mode mechanism diagram in accordance with the present invention.

FIG. 8 is a view showing a reconstruction of the failure mode mechanism after selecting "CFM" of "A Ass'y" as the central failure mode from the search result of the failure mechanism information according to the present invention.

Fig. 9 is a diagram showing a reconstruction of the failure mode mechanism after selecting "FM3" of component "P-a" as the central failure mode from the search result of the failure mechanism information according to the present invention.

The present invention relates to a method for analyzing a failure mechanism implemented to prevent a failure in a product in the development stage of a product (system), and in particular, a method for effectively identifying the cause and effect mechanism of a predicted failure mode. The present invention relates to an analytical method that improves the reliability of a developed product and further accumulates and manages analysis results so that knowledge such as personal experience and know-how related to the failure of the target product can be recycled as the organization's knowledge.

Conventionally, the main method was to estimate the cause of the occurrence of defects or failures. Known examples of methods for estimating the cause of the defect in the defect phenomenon occurring at the manufacturing stage are Japanese Patent Laid-Open No. Hei 1-167631 and Japanese Patent Laid-Open No. Hei 6-196900. These are to accumulate the conventional defect results and data of the cause and to obtain the correlation between the defect pattern and the cause of the defect, and to estimate the cause of the defect accordingly. Further, examples of using the same method for diagnosing a failure include Japanese Patent Laid-Open No. Hei 7-13617 and Japanese Patent Laid-Open No. Hei 7-271587.

All of the above known examples are for quickly and accurately performing a repair according to the contents of a phenomenon that actually occurred when a defect phenomenon or a malfunction occurs, and is a technique of estimating a direct cause according to past thoughts. Since these methods need to identify most of the failures that can actually occur, it is impossible to accurately estimate the poor properties that result in a large number of manufacturing defects due to a missing review and the characteristics of the product.

On the other hand, Korean Patent Laid-Open Publication No. 1998-80843 proposes a method for estimating a defective assembly potential. However, this not only makes the upper and lower relations of the various components unclear, but it is difficult to clearly determine the contents of third parties who do not participate in the analysis.

In general, failure modes and effect analysis (FMEA) and fault tree analysis (FTA) are widely used as methods for predicting and analyzing failure modes. FMEA is a world-renowned technique used in the reliability and safety assessment of NASA in the 1950s when NASA implements the Apollo plan for launching dalockets. Enumeration and prediction are performed by enumerating. The FTA is also a method initiated by NASA, which analyzes the undesired defects of the system by drawing the FT diagram by the analyst's own judgment by using mapping symbols and logic symbols.

In case of FMEA, it is easy to analyze the single failure mode occurring in the component of the product to be analyzed, but it is difficult to analyze the failure mode of complex failure factors caused by the combination of components or several components. . In addition, the FTA is used as a post-analysis method to analyze the cause of the trouble after the occurrence of the problem, rather than as a pre-analysis method for interpreting the possibility of the problem by predictive thinking.

Since both the FMEA and the FTA are interpreted by the analyst's own judgment, there are many differences in the quality of the results depending on the perspective of the analyst. By simply enumerating, the causal relationship between the various elements included in the mechanism is not only unclear, but there is considerable difficulty in clearly determining the contents of third parties who do not participate in the interpretation.

A method for overcoming the above problems in the implementation of FMEA is disclosed in Japanese Patent No. 0419296. In particular, a failure mode mechanism diagram is proposed as a method of analyzing the cause mechanism and the effect mechanism of the failure. have. The failure mode mechanism is a useful method for analyzing the cause mechanism and the effect mechanism of the failure mode to be analyzed, but in the expression method of the cause mechanism, the representation of essential failure factors such as design and process problems for failure phenomena caused by stress in use. There is a lack of a clear definition of the method, and the conversion and accumulation of information considering the recyclability of knowledge is necessary in order to reuse the information in the failure mode mechanism diagram, which is useful for analyzing the failure mechanism of other similar items, and there is a lack of technology. It is.

In the present invention, in order to solve the above problems of the failure mode mechanism diagram, the method of describing the failure factors included in the cause mechanism on the failure mode mechanism diagram is clearly defined, and all failure mechanism information described in the failure mode mechanism diagram. Aims to be easily recycled for failure analysis of similar items and the like.

In order to achieve the above object, the present invention provides a method for analyzing a failure mechanism, by converting a first failure mode mechanism diagram hierarchically displaying a causal relationship between an item, a failure factor, and a failure mode. Constructing a failure mode library having the item, a failure factor, and a failure mode as items, and having a logical causal relationship with the first failure mode mechanism, searching for a failure mode of another analysis target from the built failure mode library; And automatically generating, from the failure mode library, a second failure mode mechanism for the searched failure mode to be analyzed, wherein the failure factor is at least one of a design failure factor, a process failure factor, and a stress. 2 The step of automatically generating a failure mode mechanism is a cause mechanism of the another failure mode to be analyzed. Enumerating related parts and component combinations, enumerating the failure modes of the primary cause of the other analysis failure mode to the corresponding parts or component combinations, and the failure modes of the primary cause are related to the initial failure. If the cause is listed as the failure mode, design failure factor, or process failure factor of the second cause, and the failure mode of the primary cause is caused by stress in use, the cause may be the failure mode or stress of the second cause. It is characterized by having a process of enumerating as.
The present invention also provides a computer-readable recording medium recording a program for analyzing a failure mechanism, wherein the program includes a first failure mode hierarchically displaying a causal relationship between an item, a failure factor, and a failure mode for an analysis target. Constructing a failure mode library having the item, failure factor, and failure mode as items and having a logical causal relationship with the first failure mode mechanism; and converting another analysis object from the constructed failure mode library. Retrieving a failure mode and automatically generating a second failure mode mechanism for the searched failure mode from the failure mode library, wherein the failure factor is at least one of a design failure factor, a process failure factor, and a stress; And automatically generating the second failure mode mechanism diagram. Enumerating parts and component combinations related to the cause mechanism of the analytical failure mode, enumerating a failure mode of a primary cause of the other analytical failure mode into a corresponding component or component combination, and failure of the primary cause If the mode is related to the initial failure, the cause is listed as failure mode of secondary cause, design failure factor, process failure factor, and if the failure mode of primary cause is caused by stress during use Another feature is to include a failure mode of secondary causes and a process of enumerating with stress.

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According to the present invention having the above-described configuration, it is possible to effectively perform the failure prediction and analysis that is carried out to prevent the failure in the product in advance in the product development process. In addition, according to the present invention, by analyzing the effect of the failure mode and the cause mechanism in the form of a failure mode mechanism diagram to prevent the failure factors that can occur in the analysis process, and to clearly identify the causal relationship between each failure factor In addition, the consideration of the causal mechanisms that have been made in the analyst's head so far is provided to others in a schematic form, so that the analyst's thoughts can be easily communicated and further reviewed by other experts. In addition, according to the present invention, by converting the created failure mode mechanism into a structured knowledge form and accumulating it in a library and providing it to the person who analyzes it, it is possible to improve the prediction and interpretation ability while minimizing the variation according to the knowledge retention level between the implementers. Better interpretation results can be obtained. In particular, by using the accumulated knowledge, a failure mode mechanism can be automatically generated and provided, so that the analysis can be efficiently performed in a short time.

Hereinafter, with reference to the accompanying drawings will be described embodiments of the present invention; In the drawings, the same reference numerals are used to indicate the same or similar components.

1 is a flowchart of a method of analyzing a failure mechanism according to the present invention. As shown in Fig. 1, a failure mode mechanism diagram is first created in which the cause of an analysis mode failure mode is hierarchically displayed as a causal relationship between items, failure factors, and failure modes (102). The figure is converted into structured knowledge (104) and stored in storage (106). Next, using the accumulated knowledge, another analysis target failure mode is searched for, and a failure mode kinematic diagram for the detected analysis target failure mode is automatically generated (108). The term "item" is used herein to refer to a part or combination of parts associated with the mechanism of the cause of the failure mode.

In the present invention, the failure mode mechanism is divided into type A and type B, Figure 2 is a structural diagram of an example of the type A failure mode mechanism according to the present invention, Figure 3 illustrates a method for preparing a type A failure mode mechanism diagram 4 is a flowchart illustrating an example of a type A failure mode mechanism.

In FIG. 2, the upper part represents an influence meter and the lower part represents a causal system, centering on a central failure mode (Central FM or CFM) that is a failure mode to be analyzed. The influence system is a hierarchical representation of the effect on the upper system according to the occurrence of the central failure mode. E11 and E21 are the primary effects on the upper part according to the occurrence of the central failure mode (Central FM). This is a secondary effect of the occurrence of E11 and E21.

In FIG. 2, the failure mode is indicated by a rectangle, and "FM1", "FM12", "FM3", and "FM4" correspond to a failure mode caused by stress during use, and "FM2" and "FM31" are designed. Or failure mode caused by initial quality problems such as processes. Failure factors are indicated by ellipses, "S11", "S12", "S31", and "S41" correspond to the stresses causing the failure mode, and "S22" and "S32" are factors related to product / process design misses. "S23" and "S33" correspond to factors related to the production / transport process failure. "P-a" and "P-b" represented by a rectangle correspond to items. "-" Is a line for indicating a part itself and a part combination in a cause mechanism, and "<-" is a line for indicating a causal relationship between cause and effect in a cause and effect mechanism.

The cause system shows hierarchically the cause of the central failure mode, with reference to FIG. First, parts associated with the cause mechanism of the central failure mode are listed at the bottom (302). Next, a tree is created for the enumerated parts. If the occurrence of the central failure mode is caused by the characteristics of the interface between components or the combination of parts, the failure mode and the cause of the failure are arranged before the branch of the tree. If the occurrence is due to the nature of the component itself, the failure mode and failure factors are arranged after branching of the tree (304). On the left side, the failure factors related to initial failure are described on the left side of the tree, and on the right side, failure factors due to stress during use are described (306). In addition, failure factors determined as modes (states) among the listed failure factors are squares, and other failure factors such as stress, condition variation, human error, etc. are described as ellipses. In addition, a design failure factor that caused the primary cause mode and a mode (secondary) that cause it are described on the left side of the cause mode (primary) related to the initial failure, and a process failure factor on the right side. In addition, stress and its cause mode (secondary) that caused the primary cause mode on the right side, and the cause mode (secondary) that relates to the initial failure on the right side of the cause mode (primary) related to stress during use. Describe the design failures and process failures that caused the secondary cause mode.

5 is a structural diagram of an example of a type B failure mode mechanism according to the present invention, and FIG. 6 is a flowchart of a method of preparing a type B failure mode mechanism according to the present invention.

In FIG. 5, the upper part (Effect) represents an influence system and the lower part (Cause) represents a causal system centering on a central failure mode (CFM), which is a failure mode to be analyzed. In the same manner as the type A failure mode mechanism shown in FIG. 2, the influence system shows hierarchically the effect on the upper system according to the occurrence of the central failure mode, and in the drawing, E11 and E21 are different from each other according to the occurrence of the central failure mode. E12 and E22 are the primary effects of E11 and E21, respectively.

The method of indicating the failure mode and the failure factor is the same as in FIG. In FIG. 5, "P-a", "P-b", and "P-a & P-b" correspond to items.

The cause system shows hierarchically the cause of the central failure mode (CFM) with reference to FIG. First, parts or combinations of parts related to the cause mechanism of the central failure mode (CFM) are listed (602). Next, the primary cause mode of the central failure mode (CFM) is classified as related to the initial failure or due to stress during use, and is listed in the corresponding component or component combination (604). If the primary cause mode listed above is the cause mode associated with the initial failure, the cause is classified into the secondary cause mode or the design failure factor and the process failure factor, and the secondary cause mode is again classified into the same cause. Enumeration (606). If the primary cause modes listed above are stress-related cause modes in use, list them as either a secondary cause mode or stress. If the secondary cause mode is the cause mode related to the initial failure, the cause is classified into design failure factors and process failure factors, and if the secondary cause mode is the cause mode related to stress during use, the cause is identified. The causes are classified by the difference cause mode or the stress (608).

7 shows an example of knowledge conversion of the failure mode mechanism according to the present invention. The failure mode kinematics, written in type A and type B, are converted into structured knowledge for recycling of knowledge. As shown in FIG. 7, the knowledge transformation of the failure mode mechanism is performed in consideration of the causal relationship between the elements listed on the failure mode mechanism and the item, function, design failure factor, process failure factor, stress, failure mode. By converting it into a table structure consisting of six items.

When converting knowledge, the item name of the influence system contents corresponds to the upper system centered on the corresponding item in the central failure mode. Therefore, the item name in the form of "+ Top 1" and "+ Top 2" after the corresponding item name in the central failure mode To give. All failure modes and their causes represented by the square on the failure mode mechanism diagram are divided into three failure factors, design failure factor, process failure factor, and stress. Cause modes are treated as design failure factors, and cause modes associated with stress during use are treated as stress and converted. In addition, design failure factors, process failure factors, and stress expressed in ellipses are classified into the corresponding items and converted.

All the failure mode mechanisms created are systematically accumulated in the failure mechanism library of the database through this knowledge conversion process. The failure mechanism library in the form of a table with items, functions, design failure factors, process failure factors, stress, and failure modes can be retrieved through the library management menu, and edited / modified. Therefore, the content can also be directly keyed in. In addition, in order to facilitate knowledge retrieval by knowledge users, individual libraries are constructed according to the classification system for each item.

The system user who predicts the failure mode that can occur in the analysis target item and analyzes the effect and the cause mechanism of the predicted failure mode can use the failure mode prediction menu linked with the failure mechanism library. Enter the type of stress or select specific contents such as stress or design failure factors from the built individual libraries to search for possible failure modes. After selecting the required failure mode among the searched failure modes and executing the reconfiguration menu, the failure mode mechanism is also executed. Reconstructed and show the result in the form of a type B failure mode mechanism.

FIG. 8 illustrates reconstruction of the failure mode mechanism after selecting "CFM" of "A Ass'y" as the central failure mode from the search result of the failure mechanism information according to the present invention, and FIG. 9 according to the present invention. It shows the reconstruction of the failure mode mechanism after selecting "FM3" of the component "Pa" as the central failure mode among the search results of the failure mechanism information.

The above described embodiments are merely intended to enable those skilled in the art to easily understand and to practice the present invention, and are not intended to limit the scope of the present invention. Therefore, those skilled in the art should note that various modifications or changes to the above embodiments can be made within the scope of the present invention.

According to the present invention having the above-described configuration, it is possible to effectively perform the failure prediction and analysis that is carried out to prevent the failure in the product in advance in the product development process. In addition, according to the present invention, by analyzing the effect of the failure mode and the cause mechanism in the form of a failure mode mechanism diagram to prevent the failure factors that can occur in the analysis process, and to clearly identify the causal relationship between each failure factor In addition, the consideration of the causal mechanisms that have been made in the analyst's head so far is provided to others in a schematic form, so that the analyst's thoughts can be easily communicated and further reviewed by other experts. In addition, according to the present invention, by converting the created failure mode mechanism into a structured knowledge form and accumulating it in a library and providing it to the person who analyzes it, it is possible to improve the prediction and interpretation ability while minimizing the variation according to the knowledge retention level between the implementers Better interpretation results can be obtained. In particular, by using the accumulated knowledge, a failure mode mechanism can be automatically generated and provided, so that the analysis can be efficiently performed in a short time.

Claims (11)

delete delete delete delete delete delete delete delete In the method of analyzing the failure mechanism, A first failure mode mechanism diagram hierarchically displaying a causal relationship between an item, a failure factor, and a failure mode for any analysis target is converted to have the item, the failure factor, and a failure mode as an item. Constructing a failure mode library having a mechanical diagram and a logical causal relationship; Retrieving a failure mode of another analysis target from the built failure mode library, and automatically generating a second failure mode mechanism diagram for the found analysis failure mode from the failure mode library, The failure factor is at least one of design failure factor, process failure factor, and stress. Automatically generating the second failure mode mechanism diagram Enumerating parts and component combinations related to the cause mechanism of the another analysis failure mode; Enumerating the failure mode of the primary cause of the another analysis target failure mode to a corresponding component or component combination; When the failure mode of the primary cause is related to the initial failure, the process of enumerating the cause as the failure mode of the second cause, design failure factor, and process failure factor; When the failure mode of the primary cause is due to stress during use, the process of enumerating the cause as failure mode, the stress of the secondary cause Method for analyzing the failure mechanism, characterized in that. delete A computer-readable recording medium having recorded thereon a program for analyzing a failure mechanism, The program A first failure mode mechanism diagram hierarchically displaying a causal relationship between an item, a failure factor, and a failure mode for any analysis target is converted to have the item, the failure factor, and a failure mode as an item. Constructing a failure mode library having a mechanical diagram and a logical causal relationship; Retrieving a failure mode of another analysis target from the built failure mode library, and automatically generating a second failure mode mechanism diagram for the found analysis failure mode from the failure mode library, The failure factor is at least one of design failure factor, process failure factor, and stress. Automatically generating the second failure mode mechanism diagram Enumerating parts and component combinations related to the cause mechanism of the another analysis failure mode; Enumerating the failure mode of the primary cause of the another analysis target failure mode to a corresponding component or component combination; When the failure mode of the primary cause is related to the initial failure, the process of enumerating the cause as the failure mode of the second cause, design failure factor, and process failure factor; When the failure mode of the primary cause is due to stress during use, the process of enumerating the cause as failure mode, the stress of the secondary cause Record medium, characterized in that.

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