A Report Adaptive Arrangement Method for Fault Trees

Abstract

The present invention discloses a method for adaptively arranging reports for fault trees, comprising the following steps: Step 1, import the drawn fault tree and define or select the paper size for generating the fault tree report; Step 2, read the structural parameter information of the fault tree structure, and determine the scaling parameter r of the fault tree structure in the report from top to bottom; Step 3, for the fault tree structure that exceeds the layout area, determine the transfer gates in the fault tree report and decompose the fault tree structure; Step 4, regard the branch where the transfer gate is located as a new fault tree and arrange it on a new page; Step 5, add hyperlinks between the transfer gates; Step 6, generate the fault tree report according to the fault tree report format. The present invention makes the fault tree export report have the characteristics of reasonable layout and high readability.

Description

Technical Field

[0001] The present invention belongs to the fields of safety engineering and reliability engineering, and relates to a method for adaptively arranging reports for fault trees. Background Art

[0002] Fault tree analysis is a commonly used graphical analysis method, widely applied in the fields of safety engineering and reliability engineering. It can help engineers identify the causes of system failures, discover some links with relatively low safety or reliability, and thus take corresponding improvement measures to enhance system design.

[0003] During the process of fault tree analysis, high-complexity safety-critical systems often mean that the scale of the fault trees to be drawn in the analysis tool is huge, which brings great difficulties to exporting fault tree reports with high readability and standardized layouts. Currently, there is still a lack of unified understanding and standardized methods for arranging the exported reports of fault trees, and there is no unified standard for the arrangement process of logic gates such as AND gates, OR gates, and voting gates and their branch nodes in the fault tree structure, resulting in problems such as uneven readability of the reports generated by different fault tree analysis tools and unreasonable decomposition of the fault tree structure. Summary of the Invention

[0004] In order to standardize the method for arranging the exported reports of fault trees, the object of the present invention is to provide a method for adaptively arranging reports for fault trees to improve the readability of the exported reports of fault trees.

[0005] The object of the present invention is achieved through the following technical solutions.

[0006] A method for adaptively arranging reports for fault trees includes the following steps:

[0007] Step 1: Import the drawn fault tree and define or select the paper size for generating the fault tree report;

[0008] Step 2: Read the structural parameter information of the fault tree structure and determine the scaling parameter r of the fault tree structure in the report from top to bottom;

[0009] Step 3: For the fault tree structure that exceeds the arrangement area, determine the transfer gates in the fault tree report and decompose the fault tree structure;

[0010] Step 4: Regard the branch where the transfer gate is located as a new fault tree and arrange it on a new page;

[0011] Step 5: Add hyperlinks between the transfer gates;

[0012] Step 6: Generate the fault tree report according to the fault tree report format.

[0013] Preferably, the scaling parameter r is determined as follows:

[0014] First, calculate the scaling parameter r using the following formula:

[0015]

[0016] where: x represents the number of secondary nodes under the top node; d represents the interval between secondary nodes; S represents the proportionality coefficient of the layout area width to the paper width; W represents the width of the paper; L represents the width of the logic symbol;

[0017] If the scaling parameter calculated by the above formula is 1 and there are tertiary nodes in the fault tree structure, the scaling parameter r needs to be recalculated using the following formula:

[0018]

[0019] where: x1 represents the number of tertiary nodes; d1 represents the interval between tertiary node symbols;

[0020] If the scaling parameter calculated by the above formula is not equal to 1, set the minimum scaling parameter r min ;

[0021] When L * x + (x - 1) * d ≤ S * W, there is:

[0022]

[0023] When L * x + (x - 1) * d > S * W, there is:

[0024]

[0025] Preferably, in step 3, after determining the scaling parameter r of the fault tree structure in the report, when the following formula holds, the fault tree structure needs to be decomposed:

[0026] H * r * y max + h * r * (y max - 1) > T * E

[0027] Or

[0028] L * r * x max + d′ * r * (x max - 1) > S * W

[0029] where: y max represents the maximum number of levels of the fault tree structure; h represents the distance between logic symbols; x maxrepresents the maximum number of sibling nodes in the fault tree structure; d' represents the distance between sibling nodes; T represents the proportionality coefficient of the height of the layout area to the height of the paper; S represents the proportionality coefficient of the width of the layout area to the width of the paper; E represents the height of the paper; W represents the width of the paper; L represents the width of the logic symbol; H represents the height of the logic symbol;

[0030] When the scaled fault tree structure exceeds the left or right side of the layout area, convert the upper level of the logic symbols in the exceeded area into transfer gates;

[0031] When the scaled fault tree structure exceeds the lower side of the layout area, convert the upper level of the logic symbols in the exceeded area into transfer gates;

[0032] When the scaled fault tree structure exceeds the left, right or lower side of the layout area, if there is a voting gate in the upper level of the logic symbols in the exceeded area, convert the voting gate into a transfer gate;

[0033] For the scaled fault tree structure, with the position of the top node as the central axis, if the number of left and right branch nodes in the fault tree structure is unbalanced, translate the branch with more nodes in the direction of the central axis with the position of the top node as the center.

[0034] The present invention provides a normative layout method for the fault tree export report, making the fault tree export report have the characteristics of reasonable layout and high readability. The present invention takes the fault tree structure drawn in the fault tree analysis tool as the input, and through a series of normative methods and various layout algorithms, outputs a fault tree analysis report with high readability and standardized layout, which has strong practical and promotional value. Brief Description of the Drawings

[0035] Figure 1 is the flow chart of the report adaptive layout method for the fault tree;

[0036] Figure 2 is the schematic diagram of the fault tree logic symbol and paper parameters;

[0037] Figure 3 is the schematic diagram before the fault tree structure is scaled;

[0038] Figure 4 is the schematic diagram of the effect after the fault tree structure is scaled;

[0039] Figure 5 is the schematic diagram of the fault tree structure exceeding the right side of the layout area;

[0040] Figure 6 is the decomposition schematic diagram of the fault tree structure exceeding the right side of the layout area;

[0041] Figure 7 is the schematic diagram of the fault tree structure exceeding the lower side of the layout area;

[0042] Figure 8 It is a decomposition schematic diagram of the fault tree structure exceeding the lower side of the layout area;

[0043] Figure 9 It is a schematic diagram of the fault tree structure with a voting gate exceeding the lower side of the layout area;

[0044] Figure 10 It is a decomposition schematic diagram of the fault tree structure with a voting gate exceeding the lower side of the layout area;

[0045] Figure 11 It is a schematic diagram of the fault tree structure with unbalanced numbers of left and right branch nodes;

[0046] Figure 12 It is a layout schematic diagram of the fault tree structure with unbalanced numbers of left and right branch nodes. Specific implementation manners

[0047] The present invention provides a method for adaptively arranging reports for fault trees, and gives a specific process for generating fault tree reports. Figure 1 It is a flowchart of a method for adaptively arranging reports for fault trees, which includes the following steps:

[0048] Step 1: Import the drawn fault tree and define or select the paper size for generating the fault tree report.

[0049] Among them, the drawn fault tree structure will be used as the input of the method of the present invention, and the size of the paper (including paper and electronic) can be custom-set or different types of standard papers can be selected, such as A0 paper (841mm * 1189mm), A1 paper (594mm * 841mm), A2 paper (420mm * 594mm), A3 paper (297mm * 420mm), A4 paper (210mm * 297mm), A5 paper (148mm * 210mm), etc. For the convenience of description, here the paper size parameters of the fault tree report are set as height E and width W.

[0050] Step 2: Read the structural parameter information of the fault tree structure and determine the scaling parameter r of the fault tree structure in the report from top to bottom;

[0051] The structural parameter information includes the height H and width L of each logical symbol (logical gate, logical event) in the fault tree structure, the number of levels of the fault tree, the number of nodes at each level, and the interval between nodes, as Figure 2 shown. Based on the set paper size, determine the scaling parameter r of the fault tree structure in the report from top to bottom. The scaling parameter r can be calculated through the following formula:

[0052]

[0053] Where: x represents the number of secondary nodes under the top node; d represents the interval between secondary nodes; S represents the proportionality coefficient of the layout area width to the paper width, for example, it can be set to 0.95, or this proportionality system can be customized according to needs.

[0054] If the scaling parameter calculated by the above formula is 1 and there are tertiary nodes in the fault tree structure, the scaling parameter r needs to be calculated again through the following formula:

[0055]

[0056] Where: x1 represents the number of tertiary nodes; d1 represents the interval between tertiary node symbols.

[0057] If the scaling parameter calculated by the above formula is not equal to 1, in order to ensure the readability of the fault tree structure, especially for complex large-scale fault tree structures, it is required that the fault tree structure will not be infinitely reduced during layout. Usually, a threshold should be set, that is, the minimum scaling parameter r should be set min , such as r min = 0.6, the relationship between r and r min can be obtained through the following formula:

[0058] When L * x + (x - 1) * d ≤ S * W, there is:

[0059]

[0060] When L * x + (x - 1) * d > S * W, there is:

[0061]

[0062] Step 3: For the fault tree structure that exceeds the layout area, determine the transfer gates in the fault tree report, decompose the fault tree structure, and standardize the layout of the fault tree structure in the fault tree report;

[0063] After determining the scaling parameter r of the fault tree structure in the report, based on the size of the layout area of the fault tree structure in the report and combined with the scaled fault tree structure, it is possible that the scaled fault tree structure cannot be fully displayed within the layout area, and the fault tree structure needs to be decomposed so that the fault tree structure can be completely displayed within the layout area.

[0064] When the following formula holds, the fault tree structure needs to be decomposed

[0065] H * r * y max + h * r * (y max - 1) > T * E

[0066] Or

[0067] L * r * xmax +d′*r*(x max -1)>S*W

[0068] Where: y max represents the maximum number of levels of the fault tree structure; h represents the distance between logic symbols; x max represents the maximum number of nodes at the same level (nodes at the third level and below) in the fault tree structure; d′ represents the distance between nodes at the same level; T represents the proportional coefficient of the layout area height to the paper height. For example, it is designed as 0.9, and this proportional system can also be customized according to needs.

[0069] To achieve the above purpose, here the logic symbols are converted into the form of transfer gates, so as to decompose the relatively large fault tree structure. The layout of the fault tree structure in the report area should follow that the top node, the second-level node, and the third-level node are always centered, and the branch where the transfer gate is located can be regarded as a new fault tree structure for the above layout processing. Here, the following situations are mainly considered:

[0070] · When the scaled fault tree structure exceeds the left or right side of the layout area, convert the upper level of the logic symbols in the exceeded area into a transfer gate. As Figure 5 shows a schematic diagram of the fault tree structure exceeding the right side of the layout area. Among them, the rightmost of the fourth-level nodes of the fault tree structure exceeds the area range. Therefore, convert the upper-level node of the exceeded area node into a new transfer gate and arrange this branch to be displayed on another page, as Figure 6 shows the decomposition schematic diagram of the fault tree structure exceeding the right side of the layout area;

[0071] · When the scaled fault tree structure exceeds the lower side of the layout area, convert the upper level of the logic symbols in the exceeded area into a transfer gate. As Figure 7 shows a schematic diagram of the fault tree structure exceeding the lower side of the layout area. Among them, the eighth-level node of the fault tree structure exceeds the area range. Therefore, convert the upper-level node of the exceeded area node into a new transfer gate and arrange this branch to be displayed on another page, as Figure 8 shows the decomposition schematic diagram of the fault tree structure exceeding the lower side of the layout area;

[0072] · When the scaled fault tree structure exceeds the left, right or lower side of the layout area, if there is a voting gate in the upper level of the logic symbols in the exceeded area, convert this voting gate into a transfer gate. As Figure 9 shows a schematic diagram of the fault tree structure with a transfer gate exceeding the lower side of the layout area. Among them, the eighth-level node of the fault tree structure exceeds the area range, and the parent node of the upper-level node of the exceeded area node is a voting gate. Therefore, convert this voting gate node into a new transfer gate and arrange this branch to be displayed on another page, as Figure 10Shows the decomposition schematic diagram of the fault tree structure beyond the lower side of the layout area;

[0073] · For the scaled fault tree structure, with the position of the top node as the central axis, if the number of left and right branch nodes of the fault tree structure is unbalanced, in order to improve the utilization efficiency of the layout area of the fault tree structure and enhance readability, the branch with more nodes can be translated in the direction of the central axis with the position of the top node as the center. For example Figure 11 Is the schematic diagram of the fault tree structure with unbalanced numbers of left and right branch nodes. It can be seen that the number of nodes in the left branch of the fault tree structure is significantly higher than that in the right branch. Therefore, the left branch is moved in the direction of the central axis with the position of the top node as the center, and the layout effect after movement is as shown in Figure 12 Shown.

[0074] Step 4: Treat the branch where the transfer gate is located as a new fault tree and arrange it on a new page.

[0075] The fault tree branch where the transfer gate is located should be treated as a new fault tree structure, and the steps are the same as the above method. Step 5: Add hyperlinks between the transfer gates;

[0076] When the decomposition of the entire fault tree structure is completed, in order to quickly view the fault tree structure in the fault tree report, it is necessary to annotate the transfer gates generated by the decomposition and set hyperlinks to facilitate quick search of different parts of the entire fault tree structure.

[0077] Step 6: Design the fault tree report format and generate the fault tree report.

[0078] Finally, in order to reflect the entire fault tree information in the fault tree report, the following parts need to be included in the fault tree report:

[0079] · Data of logic gates and logic events included in the fault tree;

[0080] · The fault tree structure diagram after the above processing;

[0081] · The time of report generation, page number display, report name, number of logic gates, number of logic events, etc.

Claims

1. A method for adaptively arranging reports for a fault tree, characterized in that It includes the following steps: Step 1: Import the drawn fault tree and define or select the paper size for generating the fault tree report; Step 2: Read the structural parameter information of the fault tree structure and determine the scaling parameter r of the fault tree structure in the report from top to bottom; Step 3: For the fault tree structure that exceeds the layout area, determine the transfer gates in the fault tree report and decompose the fault tree structure; Step 4: Treat the branch where the transfer gate is located as a new fault tree and arrange it on a new page; Step 5: Add hyperlinks between the transfer gates; Step 6: Generate the fault tree report according to the fault tree report format; Among them: The determination process of the scaling parameter r is as follows: First, calculate the scaling parameter r through the following formula: Among them: x represents the number of secondary nodes under the top node; d represents the interval between secondary nodes; S represents the proportional coefficient of the layout area width to the paper width; W represents the width of the paper; L represents the width of the logic symbol; If the scaling parameter calculated by the above formula is 1 and there are tertiary nodes in the fault tree structure, the scaling parameter r needs to be calculated again through the following formula: Among them: x1 represents the number of tertiary nodes; d1 represents the interval between tertiary node symbols; If the scaling parameter calculated by the above formula is not equal to 1, set the minimum scaling parameter r min ; When L * x + (x - 1) * d ≤ S * W, there is: When L * x + (x - 1) * d > S * W, there is:

2. The report adaptive layout method for a fault tree according to claim 1, wherein In Step 3, after determining the scaling parameter r of the fault tree structure in the report, when the following formula holds, the fault tree structure needs to be decomposed: H*r*y max +h*r*(y max -1)>T*E Or L*r*x max +d′*r*(x max -1)>S*W Where: y max represents the maximum number of levels of the fault tree structure; h represents the distance between logic symbols; x max represents the maximum number of nodes at the same level in the fault tree structure; d′ represents the distance between nodes at the same level; T represents the proportionality coefficient of the height of the layout area to the height of the paper; S represents the proportionality coefficient of the width of the layout area to the width of the paper; E represents the height of the paper; W represents the width of the paper; L represents the width of the logic symbol; H represents the height of the logic symbol; When the scaled fault tree structure exceeds the left or right side of the layout area, convert the upper level of the logic symbol in the exceeded area into a transfer gate; When the scaled fault tree structure exceeds the lower side of the layout area, convert the upper level of the logic symbol in the exceeded area into a transfer gate; When the scaled fault tree structure exceeds the left, right or lower side of the layout area, if there is a voting gate in the upper level of the logic symbol in the exceeded area, convert the voting gate into a transfer gate; For the scaled fault tree structure, with the position of the top node as the central axis, if the number of left and right branch nodes in the fault tree structure is unbalanced, translate the branch with more nodes in the direction of the central axis with the position of the top node as the center.

Images