JP2017111657A - Design support apparatus, design support method, and design support program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate a fault tree and assist in taking notice of fault factors for an analysis target product to make FTA more efficient, without preparing any model representing the functions and behaviors of the product.SOLUTION: A design support apparatus 101 making use of failure information automatically generates a final fault tree by performing the following steps of: searching a cause-effect relation DB 114 storing cause-effect relations created based on individual failed cases in the past, for cause-effect relations including a failure event of an analysis target product; generating, based on the search result, a fault tree with the failure event of the analysis target product as the top event; searching for cause-effect relations including the failure event also for each element of the fault tree; combining the search results with the fault tree and checking the search results against the component list of the analysis target product stored in a component list DB 115; and deleting elements of the components which do not match the component list.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a design support apparatus, a design support method, and a design support program, and more particularly to a design support apparatus, a design support method, and a design support program that utilize defect information.

There is FTA (Fault Tree Analysis) as a technique for preventing product defects. FTA is an analysis technique that systematically searches for the source of failure by picking up a failure event of a product, and sequentially identifying and developing the failure factors in a hierarchical manner. This analysis result has a tree structure with the failure factor of the product at the top and the cause of the failure as a lower hierarchy. The analysis result having this tree structure is called a failure tree. A failure event of a product to be analyzed is called a top event because it is located at the top of the failure tree.
For example, when analyzing the failure factor of a certain system, the failure event of the system is described as the top event, and then the failure of the subsystem that is the cause of the failure of the system is identified and described in the lower hierarchy of the top event. Subsequently, the failure of the component that is the cause of the failure of the subsystem is identified and described in the lower hierarchy of the inhibition factor of the subsystem.
The FTA can be used when building the reliability of the product at the design stage and when investigating the cause when a defect occurs in the product. When using it in the design stage, the failure event that does not want to occur in the product is set as the top event, and the reliability is improved by taking measures against the failure factor obtained as the analysis result. In the failure factor analysis after the failure occurs, the failure event that has occurred is set as the top event, FTA is performed, and it is confirmed whether the failure factor of the top event is actually the detected failure factor.
If the failure factor can be immediately recognized, FTA can be performed in a short time. However, if you cannot immediately notice the cause of the failure, it will take time to research the literature and ask others.
Whether or not the failure factor can be noticed depends on the range of knowledge and experience of the designer who performs the FTA, but the range that each designer grasps is limited by the division of design work. In some cases, young designers with little experience need to perform FTA due to a decrease in skilled designers, so that failure factors are not immediately noticed, and it takes time to perform FTA. Furthermore, when a new part that has not been handled before is introduced and designed, new knowledge about the part to be introduced is required. Such a point may cause the FTA to take time without immediately realizing the failure factor.

From such a background, in order to efficiently perform FTA, a device that supports awareness of a failure factor is required.
In the apparatus described in Patent Document 1, a failure tree can be automatically generated, and by using this, awareness of a failure factor can be obtained. In this apparatus, MFM (Multilevel Flow Modeling) in which the relationship between a goal, a function, a relationship between functions, a relationship between a function and a goal, and a relationship between a function and a component that realizes the function is organized and organically expressed. ) Information, MFM incidental information including component behavior information that expresses the relationship between the failure and the behavior of the component when a failure occurs, and the influence propagation rule that defines the influence that the function will propagate when the function changes Based on the above, a fault tree is automatically generated.

JP 2007-259591 A

In the device of Patent Document 1, MFM information is the original data when generating the FTA. According to Patent Document 1, “a diagram expressed in MFM is generally created by a knowledge engineer. However, it is determined whether or not the MFM created by the knowledge engineer is an accurate model of the system. For this reason, a method for proving the correctness of the MFM model has been desired, and FMF is generally unfamiliar to system designers and is difficult to understand. (Paragraph 0013). In other words, in the device of Patent Document 1, a failure tree can be automatically generated, but instead, it is necessary to create MFM information for a product to be analyzed. To that end, in addition to extensive knowledge about the product, MFM information is created. Knowledge engineering knowledge is necessary to do this.
In order to utilize the device of Patent Document 1, as described above, it is necessary for the designer himself to create MFM information that requires a wide range of product knowledge and knowledge engineering knowledge. It can be said that the hurdle is high in the design department where the division of labor and the shortage of skilled designers are progressing.

In view of the above, it is an object of the present invention to provide a design support apparatus, a design support method, and a design support program for generating a failure tree using defect information and supporting awareness of a failure factor.

According to the first solution of the present invention,
A design support device,
A causal relation database (DB) that stores a causal relationship that represents a chain of causal elements including parts and phenomena for product defects,
A parts list DB that stores a hierarchical structure of parts for each product;
A generation unit for generating a failure tree of the occurrence of a defect with respect to the occurrence of a defect in the product,
With
The generation unit obtains a plurality of causal relationships including the causal elements of the top event with reference to the causal relationship DB with respect to the causal elements of the input failure top event, and each of the acquired plurality of causal relationships The first causal relationship up to the top event is cut out and acquired, and a plurality of causal relationships up to the acquired top event are combined to generate a first tree with the top event as the highest hierarchy,
The generation unit acquires one or a plurality of causal relationships including each causal element with reference to the causal relationship DB for each causal element in each layer lower than the top of the generated first tree, and acquires The causal relationship up to each causal element is obtained from each of the one or more causal relationships, and one or more causal relationships up to each acquired causal element are added to the lower hierarchy of each causal element To generate a second tree,
The generation unit refers to the parts list DB for each causal element in each hierarchy lower than the top of the generated second tree, and the causal elements not included in the parts list and the causal relationship between the causal elements in the hierarchy. To generate a fault tree,
A design support apparatus is provided.

According to the second solution of the present invention,
A design support method in a design support apparatus,
The design support apparatus includes:
A causal relation database (DB) that stores a causal relationship that represents a chain of causal elements including parts and phenomena for product defects,
A parts list DB that stores a hierarchical structure of parts for each product;
A generation unit for generating a failure tree of the occurrence of a defect with respect to the occurrence of a defect in the product,
With
The generation unit obtains a plurality of causal relationships including the causal elements of the top event with reference to the causal relationship DB with respect to the causal elements of the input failure top event, and each of the acquired plurality of causal relationships The first causal relationship up to the top event is cut out and acquired, and a plurality of causal relationships up to the acquired top event are combined to generate a first tree with the top event as the highest hierarchy,
The generation unit acquires one or a plurality of causal relationships including each causal element with reference to the causal relationship DB for each causal element in each layer lower than the top of the generated first tree, and acquires The causal relationship up to each causal element is obtained from each of the one or more causal relationships, and one or more causal relationships up to each acquired causal element are added to the lower hierarchy of each causal element To generate a second tree,
The generation unit refers to the parts list DB for each causal element in each hierarchy lower than the top of the generated second tree, and the causal elements not included in the parts list and the causal relationship between the causal elements in the hierarchy. To generate a fault tree,
A design support method is provided.

According to the third solution of the present invention,
A design support program in a design support device,
The design support apparatus includes:
A causal relation database (DB) that stores a causal relationship that represents a chain of causal elements including parts and phenomena for product defects,
A parts list DB that stores a hierarchical structure of parts for each product;
A generation unit for generating a failure tree of the occurrence of a defect with respect to the occurrence of a defect in the product,
With
The generation unit obtains a plurality of causal relationships including the causal elements of the top event with reference to the causal relationship DB with respect to the causal elements of the input failure top event, and each of the acquired plurality of causal relationships Cutting out and acquiring the causal relationship up to the top event, combining a plurality of causal relationships up to the acquired top event, and generating a first tree with the top event as the highest hierarchy;
The generation unit acquires one or a plurality of causal relationships including each causal element with reference to the causal relationship DB for each causal element in each layer lower than the top of the generated first tree, and acquires The causal relationship up to each causal element is obtained from each of the one or more causal relationships, and one or more causal relationships up to each acquired causal element are added to the lower hierarchy of each causal element And generating a second tree;
The generation unit refers to the parts list DB for each causal element in each hierarchy lower than the top of the generated second tree, and the causal elements not included in the parts list and the causal relationship between the causal elements in the hierarchy. And generating a fault tree;
A design support program for causing a computer to execute is provided.

In view of the above, it is an object of the present invention to provide a design support apparatus, a design support method, and a design support program for generating a failure tree using defect information and supporting awareness of a failure factor.

It is a figure explaining the structure of the design support apparatus using defect information. (A) It is a figure explaining the structure of a causal relationship. (B) It is a figure explaining an example of a causal relationship. It is a figure explaining an example of a FTA display screen. It is a figure explaining an example of a top event registration screen. It is a figure explaining the example of a display of the top event in a FTA display screen. It is a figure explaining the example of a display of the failure tree in a FTA display screen. It is a figure explaining the example of a display of the malfunction example relevant to the failure factor which is a component of a failure tree. It is a flowchart of a failure tree generation processing procedure. It is a flowchart of a failure tree generation processing procedure It is an example of a search result when a causal relation DB is searched using “part A, phenomenon A” as a search keyword as a top event. It is an example of the result of having cut out the causal relationship from the searched causal relationship to the top event. It is an example of the result of generating a fault tree with the top event as the highest hierarchy by combining the causal relationships up to the top event. This is an example of a failure tree obtained by sequentially searching and combining causal relationships stored in the causal relationship DB based on the top event input by the user. It is an example of a parts list. It is an example of the fault tree finally obtained by the fault tree generation process. It is an example of the causal relationship regarding the voltage drop of a power supply. It is an example of the interface for a causal relationship relevance threshold value change in a FTA display screen. It is a flowchart of the utilization procedure of a design support apparatus.

Hereinafter, two embodiments for carrying out the present invention will be described in detail with reference to the drawings.

[Overview]
The design support apparatus utilizing the defect information of the present embodiment includes, for example, a database that stores causal relationships including defect events of products to be analyzed and causal relationships created based on individual defect cases that occurred in the past. Based on this, a failure tree with the failure event of the product to be analyzed as the top event is generated, and for each element of the failure tree, the causal relationship including it is searched, and the search result is the failure tree. In addition, the final failure tree is automatically generated by collating with the parts list of the product to be analyzed, and deleting elements related to parts that do not match the parts list.

According to the present embodiment, a failure that uses a causal relationship extracted from each defect case that occurred in the past without creating a model that expresses the function and behavior of the product, such as MFM information, for the product to be analyzed. It is possible to generate a tree, support awareness of failure factors, and perform FTA efficiently.

(Equipment configuration)
A configuration of a design support apparatus using defect information will be described with reference to FIG.
A design support system that utilizes defect information includes a design support apparatus 101 and a terminal device 102 that utilize defect information. These can be connected via the network 103. The design support apparatus 101 can use a general computer and includes a central control device 104, an input device 105, an output device 106, a main storage device 107, and an auxiliary storage device 108. These are connected to each other by a bus. The auxiliary storage device 108 stores a causal relation database 114, a parts list database, a defect database 116, and an FTA result database 117 (details will be described later). Hereinafter, these are abbreviated as a causal relationship DB (Data Base) 114, a parts list DB, a defect DB 116, and an FTA result DB 117.
The auxiliary storage device 108 is an external storage device independent of the design support device 101, and both can be connected via the network 103.
The FTA display unit 109, FTA generation unit 110, FTA editing unit 111, related defect display unit 112, and FTA result registration / call unit 113 in the main storage device 107 are programs. Thereafter, when the subject is described as “the XX part” as described above, the central control device 104 reads each program from the auxiliary storage device 108 and loads it into the main storage device 107, and then the function of each program. (Detailed description below) shall be realized.
The terminal device 102 can also use a general computer, and has a central control device, an input device, an output device, a main storage device, and an auxiliary storage device (not shown). These are connected to each other by a bus.

(Causal relationship)
The causal relationship DB 114 stores the causal relationship. The causal relationship represents a chain of causality until a failure occurs. This causal relationship is created using information extracted from individual trouble cases that have occurred in the past.
FIG. 2A shows an example of the causal relationship. Each element 201 constituting the cause and effect is composed of a part 202 and a phenomenon 203. Each element is expressed as a chain of beads in order of causality. In the example of FIG. 2A, the left element is caused by the right element. As a relationship connecting elements, there are an AND condition 204 and an OR condition 205. The AND condition 204 indicates that the right element is triggered when all connected elements occur. The OR condition 205 represents that the right element is triggered when any one of the connected elements occurs.
In the example of FIG. 2A, the phenomenon B209 occurs in the component B206 when the phenomenon D209 occurs in the component D208 or the phenomenon E211 occurs in the component E210. Further, the phenomenon B207 occurs in the component B206, and the phenomenon A203 occurs in the component A202 when the phenomenon C203 occurs in the component C202. Here, the parts A to E may be not only part names but also product names, system names, and subsystem names.
In order to identify each individual causal relationship stored in the causal relationship DB 114, an ID 212 is assigned in advance.
The causal relationship shown in FIG. 2 (A) is similar in form to the FTA result in that each element constituting the cause and effect is connected by the AND condition and the OR condition. Each element constituting the component is described as a set of a part and a phenomenon occurring in the part.
FIG. 2B shows an example of the causal relationship regarding the thermal deformation of the plug. In this example, a mechanical stress 308 is generated in the insulating portion 307, and thereby a short 306 is generated in the electrode 305. Further, it shows that the heat generation 304 is generated in the electrode 303 due to the short 306 of the electrode 305, and the thermal deformation 302 is finally generated in the plug 301.

(User usage procedure)
FIG. 18 is a flowchart of a procedure for using the design support apparatus.
Below, the utilization procedure of the design support apparatus of this embodiment is demonstrated.
In accordance with the input to the input device 105 by the user, the FTA display unit 109 displays the FTA display screen 401 shown in FIG. 3 on the output device 106 (2501). The FTA display screen 401 includes a title area 402, a failure tree area 403, and a menu area 404. The title area 402 has a title input field 405, in which the title of the FTA to be performed can be input, for example, “FTA related to“ XX product activation not possible ””. The failure tree area 403 displays a failure tree. In the menu area 404, operation buttons for calling various functions are displayed.
FIG. 4 is a diagram illustrating an example of the top event registration screen.
When the top event registration button 405 is pressed, the top event registration screen 501 shown in FIG. 4 is displayed on the FTA display unit 109 (2503). The top event registration screen 501 includes a component input field 502 and a phenomenon input field 503. Each can input the part and phenomenon of the top event. In the example of FIG. 4, “XX product” is input as a part (product) and “start is not possible” as a phenomenon for the top event “XX product cannot be started”.
FIG. 5 is a diagram for explaining a display example of the top event on the FTA display screen. When the registration button 504 is pressed, the FTA display unit 109 displays the top event 610 as a set of parts and phenomena in the failure tree area 603 as shown in FIG. 5 (2505).
FIG. 6 is a diagram for explaining a display example of a failure tree on the FTA display screen.
Subsequently, when the failure tree generation button 607 is pressed, the FTA generation unit 110 executes the failure tree generation process, and the top event is based on the causal relationship stored in the causal relationship DB 114 and the component list stored in the component list DB 115. Is generated as shown in FIG. 6 and displayed on the output device 106 (2507). Details of the failure tree generation process will be described later.
In the failure tree, failure factors for the top event are displayed as a set of parts and phenomena. The user can obtain an awareness of the failure factor for the top event by looking at the failure tree, and can efficiently perform the FTA.
For example, the failure factor of “XX product activation impossible” 711 includes “power output failure” 712, “control circuit failure” 715, “power switch failure” 716, and the failure of “power output failure” 712 It can be noticed that there are “power supply circuit failure” 713, “battery output failure” 714, and the like as factors.

Hereinafter, the processing 2509 for the generated fault tree can be executed by selecting or inputting each button. If there is no corresponding button selection or input, the process 2509 can be omitted.
FIG. 7 is a diagram for displaying a failure example related to a failure factor that is a component of the failure tree.
The related defect display unit 112 is selected by the user selecting a failure factor that is a component of the failure tree displayed in the failure tree area 801 shown in FIG. 7 and selecting the related defect information display button 802. A failure case 804 associated with the causal relationship that is the cause of the failure factor can be displayed. FIG. 7 is an example when “battery output failure” 803 is selected, and a failure example of battery output failure is displayed. The defect case includes an ID 805, a title 806, a phenomenon 807, a cause 808, a countermeasure 809, and the like. The user can deepen the understanding of the contents of the causal relationship by referring to a specific failure case that is the cause of the causal relationship.
The failure factor of the failure tree is generated based on the causal relationship accumulated in the causal relationship DB 114. The defect cases are stored in the defect DB 116. A related defect case is associated in advance with the causal relationship accumulated in the causal relationship DB. As a result, the related defect display unit 112 refers to the defect DB 116 and can display related defect information for the failure factor selected by the user. As a method of associating, a method of associating by assigning the same ID (212 in FIG. 2 and 805 in FIG. 7) to the corresponding causal relationship and the defect case can be considered.
Also, the FTA editing unit 111 deletes a failure factor, changes a part name or a phenomenon name constituting the failure factor, or adds a new failure factor to the failure tree according to the input from the input device 105. Or move fault factors to different locations in the fault tree, or edit the fault tree as needed.
Further, the FTA result registration / calling unit 113 accumulates the generated failure tree in the FTA result DB 117 and can be called again.

(Fault tree generation processing)
Hereinafter, the failure tree generation process will be described with reference to the flowcharts of FIGS. 8 and 9 and FIGS.
First, the FTA generation unit 110 searches the causal relationship DB using the top event input by the user as a search keyword, and acquires the one in the causal relationship that includes the top event (901). If there is no corresponding item, the process ends (not shown in FIG. 9).
FIG. 10 shows an example of a search result when the causal relation DB is searched using the top event “part A, phenomenon A” as a search keyword.
For example, if the top event is “part A, phenomenon A”, a causal relationship including “part A, phenomenon A” as shown in FIG. 10 is retrieved. The part A is a product name such as “XX product”, a part name, and the like. Phenomenon A is a phenomenon name such as “cannot start”.
FIG. 11 is an example of a result obtained by cutting out the causal relationship from the retrieved causal relationship to the top event.

Subsequently, the FTA generation unit 110 cuts out and acquires the causal relationship up to the top event, that is, the part that causes the failure of the top event, from the acquired causal relationship (902). From the causal relationships of FIGS. 10A and 10B, causal relationships such as FIGS. 11A and 11B are acquired. Even if the top event is included as shown in the causal relationship of FIG. 10C, if there is no causal relationship that causes the failure of the top event, it is not acquired.
FIG. 12 is an example of a result of generating a fault tree with the top event as the highest hierarchy by combining the causal relationships up to the top event.
The FTA generation unit 110 combines the acquired causal relationships up to the top event to generate a fault tree with the top event as the highest hierarchy (903). In the example of FIGS. 11A and 11B, a fault tree as shown in FIG. 12 is generated. In this example, the FTA generation unit 110 combines a plurality of causal relationships (for example, FIG. 11A and FIG. 11B) with OR. In addition, you may make it couple | bond by AND, or select AND or OR by the instruction | indication from a user.
To the generated fault tree, FTA generating section 110 acquires the failure factor number _{M 1} of the first hierarchical level (904). The highest hierarchy that is the top event is the 0th hierarchy, and the hierarchy immediately below the top event is the 1st hierarchy. Thereafter, the layers are counted in order of increasing depth, such as the second layer and the third layer. In the example of FIG. 12, M ₁ is 3.
FTA generation unit 110, a first first failure factor F ₁₁ of tier generated fault tree as a search keyword to search the causality DB 114, the element in the causation, those containing the failure factor Is acquired (905). In the example of FIG. 12, the cause-and-effect DB 114 is searched using the failure factor F ₁₁ “component B, phenomenon B” 1602 as a search keyword.
Subsequently, FTA generating section 110, like the process 902, among the acquired causality, cut a causal relationship up to the failure factor F _11, obtains (906). FTA generation unit 110, a causal relationship up to the acquired failure factor is added to the lower layer of failure factor F ₁₁ (907). The FTA generation unit 110 performs the processing from 905 to 907 for the first to M _first failure factors in the first layer (908, 909). In the example of FIG. 12, the FTA generation unit 110 performs processes 905 to 907 for “part C, phenomenon C” 1604 and “part G, phenomenon G” 1606.
Further, the FTA generation unit 110 performs the first hierarchy until the lower hierarchy disappears, that is, until the lowest hierarchy, from the second hierarchy onward for the fault tree generated by the above processing. Similarly, processes 904 to 909 are performed (910, 911).

Through the above processing, a fault tree having the top event input by the user as the highest hierarchy is generated based on the causal relationship stored in the causal relationship DB.
FIG. 13 shows an example of the generated fault tree.

Subsequently, FTA generating section 110, on the generated fault tree, the first tier of the first failure factor _{F 11,} performs parts list matching stored in the parts list DB 115 (1003 ).
FIG. 14 is an example of a parts list.
In the parts list, as shown in FIG. 14, the parts constituting the product are described in a hierarchical manner for each product. Since the failure factor is composed of a part name and a phenomenon name, the FTA generation unit 110 matches the part name with the part name described in the part list of the target product.
FTA generating section 110, if matched by matching deletes the causality of the failure factor _{F 11} and the lower layer (1004, 1005). The FTA generation unit 110 performs the processing 1003 to 1005 for the first to M _first failure factors in the first hierarchy (1006, 1007). Further, the FTA generation unit 110 performs the processing 1002 to 1007 in the same manner as the first layer until the second layer and subsequent layers become the lowest layer (1008, 1009).
FIG. 15 is an example of a fault tree finally obtained by the fault tree generation process.
For example, when matching is performed between the failure tree in FIG. 13 and the component list in FIG. 14, the component C 1703, the component H 1709, and the component L 1711 in the failure tree do not match the component list. Therefore, the failure factor including the component C 1703, the component H 1709, and the component L 1711 and the causal relationship of the lower hierarchy are deleted, and the final failure tree is as shown in FIG.

The reason why matching is performed with the parts list for the generated failure tree in the processes 1001 to 1009 and the failure factor that does not match is deleted will be described below.
In processes 901 to 911, the causal relationship stored in the causal relationship DB 114 is searched using the top event and the failure factor as search keywords, and a failure tree is generated based on the searched causal relationship. The causal relationship of various products is preserved. Therefore, a part of the searched causal relationship includes the top event and failure factor of the search keyword, but the causal relationship that becomes the failure factor of the top event and failure factor is not related to the target product. May be included.
FIG. 16 is an example of the causal relationship regarding the voltage drop of the power supply.
For example, when “power supply, voltage drop” is the top event, it is assumed that the causal relationship between FIG. 16A and FIG. The cause-and-effect relationship in FIG. 16A indicates that a battery output failure 2002 has occurred due to battery aging 2003 or battery leakage 2004, resulting in a voltage drop 2001 of the power supply. The causal relationship in FIG. 16B indicates that the power supply voltage drop 2101 has been reached due to the poor connection 2102 of the outlet. The causal relationship in FIG. 16A is for products that operate by obtaining power from a battery. The causal relationship in FIG. 16B is for products that obtain power from the outside via an outlet. When the FTA analysis target is a battery-type product, the causal relationship in FIG.
The parts list for battery-powered products does not include outlets. Therefore, by matching the parts list with the failure tree, it is possible to exclude the causal relationship relating to the outlet not related to the target product and to leave only the causal relationship relating to the battery-type product.
A feature of the present embodiment is that such a matching is possible by configuring a failure factor, which is a causal component, with parts and phenomena.

In the first embodiment, in the process 901 of the failure tree generation process, the FTA generation unit 110 searches the causal relationship DB 114 using the top event input by the user as a search keyword, and sets the element in the causal relationship as an element. , Get the one that includes the top event. In process 905, the FTA generation unit 110 searches the causal relation DB 114 using each failure factor of the generated failure tree as a search keyword, and acquires an element in the cause-and-effect relationship including the failure factor. To do. In processes 901 and 905, the FTA generating unit 110 searches and acquires a related causal relationship depending on whether the top event and the failure factor are included in the causal relationship.
In the present embodiment, the FTA generation unit 110 performs matching with a parts list when searching and acquiring related causal relationships, calculates the degree of association between the causal relationship and the target product, and the degree of association is greater than or equal to a threshold value. Get only things. A method for calculating the relevance will be described later. The other part of the fault tree generation process is the same as in the first embodiment.

FIG. 17 is an example of an interface for changing the causal relationship relevance threshold on the FTA display screen.
This threshold value can be freely changed by the user by the input setting 105. For example, as shown in FIG. 17, the threshold value can be changed by providing a status bar and sliding it, and a fault tree is generated again according to the threshold value and displayed in the fault tree area 2202 as needed. To. Alternatively, an appropriate value may be input by the input setting 105.
Thus, it is possible to cope with both a case where the user wants a failure tree close to the target product and a case where a user wants a failure tree using information on other products widely by changing the threshold value. By tightening the threshold, a failure tree closer to the target product can be generated, and examination can be performed based on information with higher accuracy. By relaxing the threshold value, a fault tree can be generated using information on other products, and a wide range of awareness can be obtained from other products.

(Relevance calculation method)
A method for calculating the degree of association between the causal relationship and the target product will be described.
The FTA generation unit 110 can calculate the degree of association based on, for example, the following two policies.
Policy A: The parts constituting the product are described in a hierarchical form in the parts list. When matching with a part in a causal relationship, the higher the part list hierarchy, the higher the degree of association.
Policy B: The more the number of matching parts, the higher the degree of relevance.
Policy A is often used for various products as the end parts, such as screws and bolts, etc., so in order to evaluate the degree of causal relationship and product relevance, This is because it is important that the parts match.
If it becomes a calculation formula, it will become like Formula (1). In accordance with the formula (1), the FTA generation unit 110 sets the maximum number of parts list layers by the part list hierarchy number to the number of parts matched by the parts in the parts list and the parts in the parts list in each part list. Multiplying the numbers divided by, and adding up all the levels as the relevance.

Ｎ：部品リストの階層の最大数
ｉ： 部品リストの階層番号
Ｍ_ｉ：因果関係中の部品と部品リストの部品をマッチングした際に、部品リストの階層番号ｉで合致した部品の数

N: Maximum number of parts list hierarchy i: Part list hierarchy number M _i : Number of parts matched by part list hierarchy number i when matching parts in a causal relationship with parts list parts

  The degree of association between the causal relationship in FIG. 10A and the component list in FIG. 14 is N = 4, one component that matches the first layer of the component list, and one component that matches the second layer. Since there are two parts that match the third layer, the relevance is 4/1 × 1 + 4/2 × 1 + 4/3 × 2≈8.6. In the case of the causal relationship in FIG. 10B, N = 4, there is one part that matches the first hierarchy of the parts list, and one part that matches the second hierarchy, so the degree of association is 4 / 1 × 1 + 4/2 × 1 = 6. That is, it can be said that the causal relationship in FIG.

[Appendix]
In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.
Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files for realizing each function can be stored in a memory, a hard disk, a recording device such as an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.
Further, the control lines and information lines indicate what is considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

  A design support method or a design support apparatus / system of the present invention includes a design support program for causing a computer to execute each procedure, a computer-readable recording medium recording the design support program, and an internal memory of the computer including the design support program Can be provided by a program product that can be loaded on the computer, a computer such as a server including the program, and the like.

101 Design Support Device Utilizing Defect Information 104 Central Controller 105 Input Device 106 Output Device 107 Main Storage Device 108 Auxiliary Storage Device 109 FTA Display Unit 110 FTA Generation Unit 111 FTA Editing Unit 112 Related Defect Display Unit 113 FTA Result Registration / Call Part 114 Causal relation database 115 Parts list database 116 Defect database 117 FTA result database

Claims (15)

A design support device,
A causal relation database (DB) that stores a causal relationship that represents a chain of causal elements including parts and phenomena for product defects,
A parts list DB that stores a hierarchical structure of parts for each product;
A generation unit for generating a failure tree of the occurrence of a defect with respect to the occurrence of a defect in the product,
With
The generation unit obtains a plurality of causal relationships including the causal elements of the top event with reference to the causal relationship DB with respect to the causal elements of the input failure top event, and each of the acquired plurality of causal relationships The first causal relationship up to the top event is cut out and acquired, and a plurality of causal relationships up to the acquired top event are combined to generate a first tree with the top event as the highest hierarchy,
The generation unit acquires one or a plurality of causal relationships including each causal element with reference to the causal relationship DB for each causal element in each layer lower than the top of the generated first tree, and acquires The causal relationship up to each causal element is obtained from each of the one or more causal relationships, and one or more causal relationships up to each acquired causal element are added to the lower hierarchy of each causal element To generate a second tree,
The generation unit refers to the parts list DB for each causal element in each hierarchy lower than the top of the generated second tree, and the causal elements not included in the parts list and the causal relationship between the causal elements in the hierarchy. To generate a fault tree,
Design support device.
The design support apparatus according to claim 1,
The generation unit includes one or a plurality of causal elements including a causal element with reference to the causal relation DB with respect to the causal element of the input failure top event or each causal element in each layer lower than the top of the first tree. When the causal relationship is acquired, the component list DB is referred to, the relevance between the causal relationship and the component is calculated, the causal relationship having a relevance higher than a predetermined threshold is extracted, and the first tree is respectively obtained. Or the design support apparatus characterized by producing | generating a 2nd tree.
The design support apparatus according to claim 2,
The generation unit, when matched with a causal component, matches the higher level of the component list hierarchy, and the higher the number of matching components, the higher the degree of relevance is evaluated. Design support device.
The design support apparatus according to claim 3,
The generation unit multiplies the number of parts matched in the causal part and the parts in the parts list by dividing the maximum number of parts list hierarchy by the part list hierarchy number in each part of the parts list. A design support apparatus characterized in that, for all hierarchies, the degree of relevance is the sum of the levels.
The design support apparatus according to claim 2,
The design support device, wherein the generation unit changes a threshold value by an input from a status bar or an input device.
The design support apparatus according to claim 1,
A display unit for displaying a display screen including a title area, a failure tree area, a menu area having a top event registration button and a failure tree generation button;
Further,
When the top event registration button is pressed, the generation unit displays a top event registration screen including a part and a phenomenon input column, and a causal element including a top event part and a phenomenon is input by an input device.
When the failure tree generation button is pressed, the generation unit sets the top event as the highest hierarchy based on the causal relationship accumulated in the causal relationship DB and the component list accumulated in the component list DB. A design support apparatus that generates one tree, a second tree, and / or a fault tree and displays the tree on an output device.
The design support apparatus according to claim 1,
A defect DB that stores the associated defect cases in advance in association with the causal relationships accumulated in the causal relation DB;
When a causal element of the displayed failure tree is selected, a related defect display unit that displays a defect case associated with the causal relationship of the selected causal element with reference to the defect DB,
A design support apparatus further comprising:
The design support apparatus according to claim 1,
According to the input from the input device, the causal element is deleted from the fault tree, the parts and / or phenomena constituting the causal element are changed, the new causal element is added, and the causal element is moved to another position in the fault tree. An editing unit that edits the fault tree by any one or more,
A design support apparatus further comprising:
The design support apparatus according to claim 1,
A result registration / call unit that accumulates the generated failure tree in the result DB and / or calls the failure tree from the result DB.
A design support apparatus further comprising:
The design support apparatus according to claim 1,
The design support apparatus is characterized in that the causal relationship is such that the factors leading to the occurrence of the failure are connected in a cascading order, and each factor is expressed by a combination of parts and phenomena.
The design support apparatus according to claim 1,
The design support apparatus is characterized in that the causal relationship is an AND condition and / or an OR condition as a relation connecting causal elements.
The design support apparatus according to claim 11,
The design support apparatus, wherein when the causal relationship is combined, the generation unit couples each causal relationship to an upper layer by OR.
The design support apparatus according to claim 1,
The design support apparatus, wherein the causal element part is one of a part name, a product name, a system name, and a subsystem name.
A design support method in a design support apparatus,
The design support apparatus includes:
A causal relation database (DB) that stores a causal relationship that represents a chain of causal elements including parts and phenomena for product defects,
A parts list DB that stores a hierarchical structure of parts for each product;
A generation unit for generating a failure tree of the occurrence of a defect with respect to the occurrence of a defect in the product,
With
The generation unit obtains a plurality of causal relationships including the causal elements of the top event with reference to the causal relationship DB with respect to the causal elements of the input failure top event, and each of the acquired plurality of causal relationships The first causal relationship up to the top event is cut out and acquired, and a plurality of causal relationships up to the acquired top event are combined to generate a first tree with the top event as the highest hierarchy,
The generation unit acquires one or a plurality of causal relationships including each causal element with reference to the causal relationship DB for each causal element in each layer lower than the top of the generated first tree, and acquires The causal relationship up to each causal element is obtained from each of the one or more causal relationships, and one or more causal relationships up to each acquired causal element are added to the lower hierarchy of each causal element To generate a second tree,
The generation unit refers to the parts list DB for each causal element in each hierarchy lower than the top of the generated second tree, and the causal elements not included in the parts list and the causal relationship between the causal elements in the hierarchy. To generate a fault tree,
Design support method.

A design support program in a design support device,
The design support apparatus includes:
A causal relation database (DB) that stores a causal relationship that represents a chain of causal elements including parts and phenomena for product defects,
A parts list DB that stores a hierarchical structure of parts for each product;
A generation unit for generating a failure tree of the occurrence of a defect with respect to the occurrence of a defect in the product,
With
The generation unit obtains a plurality of causal relationships including the causal elements of the top event with reference to the causal relationship DB with respect to the causal elements of the input failure top event, and each of the acquired plurality of causal relationships Cutting out and acquiring the causal relationship up to the top event, combining a plurality of causal relationships up to the acquired top event, and generating a first tree with the top event as the highest hierarchy;
The generation unit acquires one or a plurality of causal relationships including each causal element with reference to the causal relationship DB for each causal element in each layer lower than the top of the generated first tree, and acquires The causal relationship up to each causal element is obtained from each of the one or more causal relationships, and one or more causal relationships up to each acquired causal element are added to the lower hierarchy of each causal element And generating a second tree;
The generation unit refers to the parts list DB for each causal element in each hierarchy lower than the top of the generated second tree, and the causal elements not included in the parts list and the causal relationship between the causal elements in the hierarchy. And generating a fault tree;
Design support program to make computer execute.

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