JPH11184875A - Method for preparing ft diagram and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily prepare an FT diagram useful to trouble shoot. SOLUTION: A keyword group is previously set, and a middle progress pertinent to a selected password is extracted from a data base part 21 by an FT processing part 24, and displayed by a result outputting part 25 by using the data base part 21, inputting part 22, keyword processing part 23, FT processing part 24, and result outputting part 25. Thus, an FT diagram for executing the research of the cause of a certain kind of failure can be prepared, and not only the cause of the failure (final solution) but also the middle progress can be outputted in the form of the FT diagram.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an FT diagram (Falt Tree Diagra
m: a method and apparatus for creating a causal relationship of possible failures in the form of a tree diagram), which is useful for analyzing failure occurrence paths and causes.

[0002]

2. Description of the Related Art Conventionally, a failure diagnosis type expert system as shown in FIG. The failure diagnosis type expert system shown in FIG. 19 includes a database unit 101, an input unit 102, and an FT processing unit 1.
03 and a result output unit 104. Database part 1
At 01, an FT diagram is stored in a database. Using this FT diagram, a question screen is displayed for each option (item) in the FT diagram, and the FT processing unit 103 sequentially follows the FT diagram in a question-and-answer format in which the operator selects by the input unit 102. Then, as shown in FIG. 20, the result output unit 104 outputs the final solution (the cause of the defect) as the result 105.

FIG. 20 shows a conventional result output example, in which only the final solution "the cause is xxxx" is printed.

[0004] In the part of the FT diagram other than the output result (final solution), only a part of the FT diagram traced at the stage of the question and answer on the way can be viewed as an option in the question and answer. , And are not displayed or printed in a list format as an FT diagram.

[0005]

As described above, in the conventional diagnostic expert system, only the part of the FT diagram can be viewed as an option at the question-and-answer format stage. However, among the options on the way, the part that is not selected in the question-and-answer session has a drawback that it is unclear what result will be linked thereafter. That is, the whole picture cannot be grasped.

[0006] Therefore, the conventional diagnostic expert system is not suitable for the work (troubleshooting) of narrowing down the cause of a defect from various events. In other words, at the time of the failure, most of the failure events were not identified,
It is necessary to narrow down the cause of the trouble while troubleshooting, but if the entire image of the FT diagram is not visible, the trouble cannot be efficiently performed.

In the conventional diagnosis-type expert system, since the question-and-answer format uses options (items) in the FT diagram, an unknown (UNKNOW:
If there is much to respond), the question-and-answer session will not proceed, and a valid result output will not be obtained.

The present invention has been made in view of the above-mentioned problems of the prior art, and its object is to trace an FT diagram halfway through the FT diagram so that it can be used to narrow down the cause of a problem while troubleshooting when the problem occurs. An object of the present invention is to provide a method and apparatus for creating an FT diagram that outputs as a result all options to be viewed when going.

[0009]

In order to solve the above-mentioned problems, a method of creating an FT diagram according to the present invention determines a keyword group in advance in a database-based FT diagram, and extracts a process corresponding to the selected keyword. The extracted events are output again in the form of an FT diagram.

An FT diagram creation apparatus according to the present invention for solving the above-mentioned problems comprises a database unit for converting an FT diagram into a database and a keyword group set in advance, an input unit for inputting a keyword, and the database-converted FT diagram. A FT processing unit for extracting a phenomenon related to the keyword inputted from the FT processing unit, and processing the extracted events again in the form of an FT diagram; and a result output unit for outputting the FT diagram obtained by the FT processing unit. It is characterized by the following.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an FT diagram creating apparatus according to an embodiment of the present invention. This FT diagram creation device includes a database unit 21, an input unit 22, a keyword processing unit 23, an F
It comprises a T processing unit 24 and a result output unit 25. Although the details will be described later, a keyword group is determined in advance, and the progress corresponding to the selected keyword is extracted and output (printing or image display). I have.

Here, the database unit 21 and the input unit 2
2. The keyword processing unit 23 and the FT processing unit 24 constitute FT diagram creation means and have the following functions. Note that F
The T diagram creation means is mainly realized by a computer and its software (hereinafter, FT diagram creation program). (1) The database unit 21 is a database of FT diagrams related to a defect of the same kind that occurred in the past for a certain defect. As described later, a keyword group is set in the database unit 21 in advance. (2) The input unit 22 is used for inputting, as a keyword, a feature of a product or a defect situation from an FT diagram related to a defect of the same cause for a certain defect. (3) The keyword processing unit 23 performs a process of extracting a phenomenon related to the keyword input by the input unit 22. (4) The FT processing unit 24 stores the FT in the database unit 21 based on the phenomenon extracted by the keyword processing unit 23.
A process for extracting an event related to a keyword from the diagram and creating it again in the form of an FT diagram is performed.

The result output section 25 outputs the FT diagram newly created by the FT diagram creating means as a result. This output includes printing and image display.

As described above, in order to output as a result all options (options called by keywords in the FT diagram) to be viewed when following the FT diagram, the concept of keywords is used in the present invention. In this case, keywords corresponding to all the events of the FT diagram in the database are assigned in advance. Then, by inputting a keyword at the earliest stage of using the FT diagram creating apparatus, a portion related to the keyword is extracted from the FT diagram in the database unit 21 and is reconstructed as a form of the FT diagram. Fix and output as result.

In the example shown in FIG. 2, in response to the keyword input 26, the F
Item 2 represented by a thick line among all items 1 to 19 in the T diagram,
Assuming that 3, 4, 6 to 14, 14 to 16, 18, and 19 are items related to the keyword, the items 2, 3, 4 to 6, 14 to 16, 18, and 19 related to these keywords are stored in the database unit 21. Extracted from the FT diagram inside, and reconstructed them again as the shape of FT diagram 27,
Is output as a result.

Referring to FIGS. 3 and 4, the assignment of keywords to all phenomena in the FT diagram in the database will be described. FIG. 3 shows the concept of a database-based FT diagram, and FIG. 4 shows the concept of keyword information of each factor of the database-based FT diagram.

As shown in FIG. 3, upper phenomena 1 are associated with lower phenomena A, B, C,.
.. Are associated with their phenomena a, b, c..., And their causes (final solutions) i, ii. By describing the causal relationship of failures in the form of a tree diagram in which lower-level factors are related to higher-level factors in order from the highest level to the lowest level, certain types of faults that have occurred in the past for the same cause Are stored in a database.

As shown in FIG. 4, all the phenomena of the FT diagram compiled in the database as shown in FIG. 4 correspond to keywords, for example, one kind of a keyword indicating a feature of a product or a defect situation for a certain defect, or A plurality of types are allocated in advance as needed. In the example of FIG. 4, a plurality of types of keywords i, ii, iii...

Each keyword is further selected as required, as shown in FIG. In the example shown in FIG. 5, options a, b, and c exist for the keyword i, and the keyword ii
Has options d, e, and f.

When there are a plurality of types of these keywords, for example, three types (keyword i, keyword ii, keyword iii), each item of the FT diagram in the database is
For keyword i, keyword ii, and keyword iii,
Each has information. In FIG.
Among the options a, b, and c of the keyword i, the option corresponding to the phenomenon A, for example, the option a is provided as the information of the keyword i.

[0021] The keyword is an FT in a database.
This is used to extract only relevant parts from a figure using a certain keyword. As described above, keywords are assigned to each of the phenomena in the database-based FT diagram,
This is preset in the database unit 21. When a keyword is selected, an operation of sorting the phenomena of the FT diagram created in the database using the selected keyword is performed, so that the FT diagram having the phenomena related to the keyword as an item is performed. Can be created anew.

As shown in FIG. 6, the parent-child relationship is provided as information in all the items of the FT diagram in the database. That is, in the FT diagram in the database, it is possible to know what items each item has at the top and what items have each item at the bottom. As can be understood from FIG. 3, FIG. 6 shows that the item "phenomenon A" in the database-based FT diagram has parent information 1 indicating that there is a phenomenon 1 in the upper rank, and phenomena a, b... In the lower rank. .. Are provided.

As a result, one event or one event of the FT diagram from which only the portion related to the keyword is extracted is created again as an FT diagram by clarifying the parent-child relationship. That is, the concept of parent-child relationship assigned to each item of the database-based FT diagram has the function of re-creating a related portion extracted from the database-based FT diagram using the above-described keyword as an FT diagram. I have.

FIG. 7 shows a processing flow for creating an FT diagram. In FIG. 7, the operator executes an FT diagram creation program of a computer constituting the FT diagram creation device (step S1), and then the operator operates the input unit 22 to select a keyword i and then a keyword ii. (Steps S2 to S3), the FT diagram creating apparatus creates an FT diagram in which a phenomenon related to the keyword is an item (step S4). The FT diagram newly created with the phenomena related to the keyword as an item is displayed in the result display unit 25.
Is output by printing or display.

FIG. 8 shows a flow of the whole process of the FT diagram creating apparatus. In FIG. 8, when the computer is started, the FT diagram creation mode is selected, the FT diagram creation device is operated, and the keyword i is selected, each of the phenomena for creating the FT diagram in the database unit 21 is selected. (Steps S11 to S13) Then, when a keyword ii is selected, the items sorted by the sorting operation based on the keyword i (the respective events matching the selected keyword i) are selected. Sorting is further performed on the selected keyword ii (step S14), and the above-described sorting operation is repeated by the set number of keywords to newly create an FT diagram with phenomena related to the input keyword as items (step S15). Then, the obtained FT diagram is displayed on a screen (step S16),
It is output by printing (step S17).

FIG. 9 shows an example of the output result. In FIG.
FIG. 4 illustrates an FT diagram that is extracted and displayed from the FT diagram in the database illustrated in FIG. 3 and that leads to a final solution.

(Specific Example) Next, a specific example of the present invention will be described with reference to FIGS. In this specific example, as an example of a certain kind of malfunction, "oil leak malfunction related to hydraulic equipment" is taken as an example, and as keywords, "oil leak location" and "type of seal" are taken as examples, and as shown in FIG. A database section 21 in which FT diagrams related to failures of the same cause that have occurred in the past regarding equipment related oil leakage failures, a database section 21, an input section 22, and types of oil leakage locations and seals according to the input from the input section 22 Using a keyword processing unit 23 for selecting and inputting a keyword related to the keyword and a keyword related to the location of the oil leak and the type of the seal, a portion related to the keyword is extracted from the FT diagram in the database, and is newly created as the FT diagram. F
An FT diagram creation device including a T processing unit 24 and a result output unit 25 that outputs the newly created FT diagram as a result is configured. Here, the FT processing unit 24 has a function 24a for extracting events related to the keyword and a function 24b for reconstructing the FT diagram based on the parent-child relationship between the extracted events.

In the example of FIG. 10, in response to the input from the input unit 22, the keyword processing unit 3 selects "housing" from the options as the keyword i relating to the oil leak location, and selects the option "keyword ii" relating to the type of seal. "O-ring", and "lip seal" is input as a keyword iii. Thereby, FT
The processing unit 24 extracts a part related to the housing, the O-ring, and the lip seal from the FT diagram regarding the oil leak stored in the database in the database unit 21 and newly performs FT.
A figure is created, and the result output unit 25 outputs the figure.

FIGS. 11 and 1 show examples of keyword selection operations.
2 will be described. Figure 1 when selecting the keyword i
A screen 28A shown in FIG. 1 is displayed, and one of a plurality of options 29 (an “rotating shaft, a reciprocating rod, and a piston”
And press the OK button 30. When the keyword ii is selected, a screen 28B shown in FIG. 12 is displayed, and one of the options 29 (“O-ring” in FIG.
Press the OK button 30. If there is no suitable option, the UNKNOWN (unknown) button 31 is pressed.

FIGS. 13 and 14 show examples of FT diagrams created and displayed by the present FT diagram creating apparatus. However, due to space limitations, there is only one FT diagram, which is divided into FIG. 13 and FIG. 14, but the O-ring 2, O-ring 1, mating surface 2, fitting portion 2 and O-ring 6 in FIG. Are O-ring 2, O-ring 1, mating surface 2, and fitting portion 2 in FIG.
13 and FIG. 14 are connected to one.

Next, the effectiveness of the present invention will be described with reference to FIGS. FIG. 15 shows an FT diagram created and displayed by the present FT diagram creation apparatus for a certain failure case, and FIG. 16 shows an FT diagram created and displayed by an experienced person for the same failure case. From the comparison between the two figures, the FT diagram created by the present FT diagram creating apparatus is compared with the FT diagram created by the experienced person.
It can be clearly seen that the T diagrams almost coincide. Of the FT diagrams created by experienced persons, the two items surrounded by broken lines in FIG. 16 do not match, but this could be improved by modifying the database. Conversely, the FT diagram created by this FT diagram creating apparatus is shown in FIG.
The eleven items surrounded by the broken line in 5 are more than the FT diagrams created by the experienced person, which is superior in this respect.

(Details of Database) Next, with reference to FIGS. 17 and 18, a further description will be given of the FT diagram creating apparatus shown in the above specific example. This FT diagram creation device was basically constructed using commercially available expert system construction application software.

An expert system is an AI (Artific
ial Interigence) is one of the practical application areas of the method, which uses the knowledge of humans (experts) like the rules of thumb (sometimes called seori) to solve problems. It is a system that has

Therefore, when the FT diagram creating apparatus shown in the above specific example is considered as an expert system, it becomes as shown in FIG.

In FIG. 17, the expert system 4
0 is a knowledge base 41 (corresponding to the database 21), an inference mechanism 42 (corresponding to the keyword processing unit 23 and the FT processing unit 24), and a working memory 43 (corresponding to the keyword processing unit 23).
And the FT processing unit 24). The knowledge base 41 is provided with basic knowledge and empirical knowledge of a specialist (experienced person) 44, and has objects, rules, and the like to be described later. The working memory 43 is provided with data and conditions (corresponding to keywords) provided by the user 45. The working memory 43 is used by the inference mechanism 42 for its processing.
The inference mechanism 42 has a function corresponding to the CPU of the computer, and is a system (program or database) constructed.
It operates based on the program inside. That is, the inference mechanism 42 matches the keyword from the user 45 with the knowledge base 41.
, A new FT diagram including events related to the keyword is created by inference, and the result is given to the user 45.

Here, the tool of the expert system 40 is an object thinking type expert system, and the knowledge base is composed of a combination of rules and objects. The rules describe database knowledge and ideas, and the objects describe supplementary explanatory elements of individual events (objects) described in the rules. FIG. 18 shows details of the knowledge base.

The knowledge base (a database of the FT diagram) 50 shown in FIG. 18 includes a rule description section 51 and an object description section 52. To give a specific example of the rule, Rule 1 describes that the pipe tube pipe and the joints are in a parent-child relationship with respect to the failure event “housing and piping leak”, respectively,
Rule 2 describes that the defect of the O-ring and the entrapment of foreign matter are in a parent-child relationship with the upper and lower children, respectively, for the failure event “piping tube pipe”. On the other hand, as a specific example of the object, the object A
Describes that the keyword i for the failure event “housing and pipe leakage” is “connection” and the keyword ii is “O-ring”, and the object B is the keyword for the failure event “entrapment of foreign matter”. It is described that i is a “connection” and the keyword ii is an “O-ring”.

In the above-described specific example, the FT diagram is created for an oil leak defect relating to a hydraulic device. However, the present invention is not limited to this, and the FT diagram can be created for any defect. It is.

[0039]

As can be seen from the above description, according to the first aspect of the present invention, a keyword group is determined in advance in a database-based FT diagram, and an intermediate course corresponding to the selected keyword is extracted. FT for the extracted events
Since it is characterized in that it is output in the form of a diagram, it is possible to easily create an FT diagram for investigating the cause of a certain kind of defect. In addition, as a result, not only the cause of the failure (final solution) but also the middle of the failure is output in the form of an FT diagram, so that it is possible to establish a troubleshooting method or the like for guiding the cause of the failure.

According to the second aspect of the present invention, the FT
A database unit for converting the figure into a database and a keyword group set in advance, an input unit for inputting a keyword, and a phenomenon related to the keyword input from the database-based FT diagram are extracted, and the extracted events are renewed. An FT processing unit for processing in the form of an FT diagram;
Since a result output unit for outputting the FT diagram obtained by the processing unit is provided, it is also possible to easily create an FT diagram for investigating the cause of a certain defect in the same manner.
In addition, as a result, not only the cause of the failure but also the middle of the failure is output in the form of an FT diagram, so that it is possible to establish a troubleshooting method or the like for guiding the cause of the failure.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an FT diagram creation device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between an FT diagram made into a database and an FT diagram extracted therefrom.

FIG. 3 is a block diagram showing the concept of an FT diagram in a database.

FIG. 4 is a block diagram showing the concept of keyword information of each factor of the FT diagram in the database.

FIG. 5 is a block diagram illustrating the concept of a keyword in a selection format.

FIG. 6 is a block diagram showing the concept of parent-child information possessed by each factor in the FT diagram made into a database.

FIG. 7 is a diagram showing a processing flow for creating an FT diagram.

FIG. 8 is a diagram showing a flow of an entire process of the FT diagram creation device.

FIG. 9 is a diagram showing an example of an output result according to the present invention.

FIG. 10 is a block diagram showing a configuration of an FT diagram creation device according to a specific example of the present invention.

FIG. 11 is a diagram showing an example of a keyword selection screen.

FIG. 12 is a diagram showing an example of a keyword selection screen.

FIG. 13 shows an F created and displayed by the FT diagram creating apparatus of the present invention.
The figure which shows an example of T figure.

FIG. 14 is a diagram showing a continuation of the FT diagram of FIG. 13;

FIG. 15 is a diagram showing an FT diagram created by a FT diagram creating apparatus of the present invention for a certain failure case.

FIG. 16 is a diagram showing an FT diagram created by an experienced person for the same failure case as in FIG. 15;

FIG. 17 is a diagram showing an FT diagram creation device as an expert system.

FIG. 18 is a diagram showing details of a knowledge base.

FIG. 19 is a block diagram showing a conventional configuration example.

FIG. 20 is a diagram showing a conventional output result example.

[Explanation of symbols]

 Reference Signs List 21 database unit 22 input unit 23 keyword processing unit 24 FT processing unit 25 result output unit 26 keyword input 27 extracted FT diagram 28A, 28B keyword selection screen 29 options 30 OK button 31 UNKNOWN button 40 expert system 41 knowledge base 42 inference mechanism 43 Working Memory 44 Expert (Experienced) 45 User 50 Knowledge Base 51 Rule Description 52 Object Description 53, 54 Specific Examples of Rules 55, 56 Specific Examples of Objects

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ichiro Hattori 1200, Higashi-Tanaka, Komaki City, Aichi Prefecture Mitsubishi Heavy Industries, Ltd. Nagoya Guidance Propulsion System Works

Claims (2)

[Claims] 1. An FT diagram wherein a keyword group is determined in advance in a database-based FT diagram, an intermediate course corresponding to a selected keyword is extracted, and the extracted events are output again in the form of an FT diagram. Diagram creation method. 2. A database section in which an FT diagram is made into a database and a keyword group is set in advance, an input section for inputting a keyword, and the FT made in the database
Extract the phenomena related to the entered keyword from the figure,
FT that processes the extracted events again in the form of an FT diagram
An FT diagram creation device, comprising: a processing unit; and a result output unit that outputs an FT diagram obtained by the FT processing unit.