JP6907720B2 - Prioritization method - Google Patents

Description

The present invention relates to a method of prioritizing conflicts to be resolved that hinders performance improvement in product design.

Conventionally, Japanese Patent Application Laid-Open No. 07-110771 is available as a technique in such a field. The relationship between design changes and performance changes is not 1: 1 but 1: many. That is, even when one design part is changed, there are a part where the performance is improved and a part where the performance is lowered, that is, a plurality of results correspond to one change. In reality, design changes are made at multiple locations, and performance changes corresponding to each design change occur.

Japanese Unexamined Patent Publication No. 07-110771

However, in the conventional contradictory model described above, it is not possible to summarize the overall performance change only by looking at the causal relationship. Therefore, it was difficult to identify the contradictory items due to the design change. Therefore, when there are multiple conflicts that hinder the performance target of the product, we want to prioritize the conflicts to be resolved by using mathematical optimization technology from the causal model in order to efficiently resolve the conflicts. There is a request.
The present invention provides a prioritization method for prioritizing conflicting points to be resolved.

The prioritization method according to the present invention includes a causal model DB that stores a causal model in which a design change portion and a performance that changes due to the design change are associated in advance, and improves the performance caused by the design change and its contradictory performance. This is a prioritization method for determining the priority of conflicts to be resolved, and the causal model stored in the causal model DB is the total number of changes in each performance caused by design changes per unit. Is further provided with an allocation model that is allocated as the numerical value of each performance change, and based on the numerical value of the state change allocated in the allocation model, the combination of the performance that is improved and the performance that is decreased by the design change is specified, and the contradictory points. Prioritize.
As a result, the performance change caused by the design change can be quantified, and the contradictory part to be resolved with priority even if the design change part is diverse can be easily identified.

Thereby, it is possible to provide a prioritization method for prioritizing the contradictory points.

It is a figure which shows the structure of the prioritization apparatus. It is a figure which shows an example of the QFD table used as the input design information. It is a figure which shows an example of a causal model. It is a figure which shows an example of the allocation model which concerns on design variable R and required performance A, G. It is a figure which shows an example of the distribution model which specified the contradictory part. It is a figure which shows an example which calculates the size of a contradictory by the margin amount of required performance and the unachieved amount. It is a figure which shows an example which calculates the size of a contradiction by the square of the unachieved amount. It is a figure which shows the operation flow of prioritization.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the prioritization device 1 includes a design information input unit 11, a causal model database 12 (hereinafter, causal model DB), a causal model extraction unit 13, a contradictory location identification unit 14, and a priority order. A setting unit 15 and a display unit 16 are provided. For example, the design information input unit 11 is a computer input device, the causal model DB 12, the causal model extraction unit 13, the contradictory location identification unit 14, the priority setting unit 15 is a computer storage device and an arithmetic unit, and the display unit 16 is a computer. It can be implemented by the display of.

The design information input unit 11 inputs design information. For example, a quality function development table (QFD table) as shown in FIG. 2 is used for the design information input to the design information input unit 11. In this QFD table, there are multiple required performances, the target value of each required performance, the current value, the importance, and the required performance value changed by changing the design variable, the design variable domain, and the design variable. Information on the optimal solution is described. In the QFD table shown in FIG. 2, the required performance exists from A to L and the design variable exists from A to X. By increasing the design variable “R” by one unit, the required performance “G” Is improved by 3, but the required performance "A" is -1, and it is described that it is deteriorated by 1. In the following, these changes in performance will be referred to as the degree of influence. In FIG. 2, a part of the QFD table is omitted from the display.

As shown in FIG. 3, the causal model DB 12 stores the design information, the required performance, the physical variables corresponding to the intermediate layer thereof, and the causal model in which the degree of influence of the design variables on the required performance is stored. That is, in the causal model, the design change location and the performance that changes due to the design change are associated in advance.

For example, the causal model stored in the causal model DB 12 shown in FIG. 3 has "acceleration" and "cruising distance at low speed" as required performance, "battery capacity" as design variables, and "weight", "draft" and "water" as physical variables. This is an example composed of "underwater resistance", "energy consumption per unit distance", "energy amount", and a path connecting these, and the required performance influence is distributed to the path connecting the required performance and design variables. There is. In the causal model DB 12, information on the distributed required performance influence is also stored at the same time. In FIG. 3, the arrows in the same frame as the design variables indicate the increasing / decreasing direction when the design variables are increased / decreased, and the arrows on the left side indicate the design when the design variables are increased. It shows the case where the variable is reduced.

The causal model extraction unit 13 selects a causal model related to the selected design variable and the required performance from the causal model stored in the causal model DB 12. In addition, the causal model extraction unit 13 extracts a distribution model including physical variables from the selected causal model, and distributes the degree of influence if there is a branch in the path in the distribution model. In other words, the causal model extraction unit 13 extracts an allocation model in which the total number of changes in each performance caused by the design change per unit is distributed as a numerical value of each performance change.

For example, the distribution model when focusing on the design variable “R” and the required performances “A” and “G” is in the state shown in FIG. In addition, in FIG. 4, the contents of the QFD table shown in FIG. 2 are reflected, and it is shown that when the battery capacity increases by 1 unit, the required performance “A” decreases by 1 and the required performance “G” increases by 3. ing. Further, in the distribution model shown in FIG. 4, there is a branch in the path, and the degree of influence is distributed to "Rp1" to "Rp4". For example, in FIG. 4, it is shown that “-2” is distributed to “Rp1” and “5” is distributed to “Rp4” for the one having the influence degree of the required performance “G” of “3”. Similar to the causal model DB shown in FIG. 3, the arrow on the left side of the variable indicates the increasing / decreasing direction when the design variable is increased. For example, the design variable “R” is increased. In some cases, "Rp1" to "Rp3" decrease and "Rp4" increases.

The contradiction location specifying unit 14 specifies a combination of the performance improved by the design change and the performance (contrarian performance) decreased with the design change based on the numerical value of the state change distributed in the distribution model. That is, in the distribution model shown in FIG. 5, the contradiction location identification unit 14 has three locations in which the directions indicated by the arrows on the left side of the variables of the distribution model shown in FIG. And "Rp4", and "Rp3" and "Rp4" are identified as contradictory points. That is, the points indicated by the dotted arrows on FIG. 5 are opposite points because the directions of the arrows are different from each other.

The priority order setting unit 15 calculates the size of each contradiction with respect to the contradiction portion specified by the contradiction location specifying unit 14. As a result, the priority setting unit 15 prioritizes the contradictory points. As the calculation method by the priority setting unit 15, for example, either a method of using the margin amount and the unachieved amount of each required performance or a method of using the square of the unachieved amount can be used.

Here, a method of prioritizing based on the margin amount and the unachieved amount of each required performance will be described by the priority setting unit 15. Here, as shown in FIG. 6, it is assumed that the required performance "A" has a margin amount of 1 and the required performance "G" has an unachieved amount of 2. The priority order setting unit 15 determines that, among the contradiction points specified by the contradiction part identification unit 14, the part having the largest difference in absolute value is the contradiction part to be eliminated.

Here, for example, the degree of influence of "Rp2" is 3 in total of -1 from the required performance A side and +4 from the required performance G side, and the degree of influence of "Rp4" is -10, so "Rp2". The difference between the absolute value of "Rp4" and "Rp4" is 13. Similarly, the difference between the absolute values of "Rp1" and "Rp4" is 14, and the difference between the absolute values of "Rp3" and "Rp4" is 13. In this case, the priority setting unit 15 determines that "Rp1" and "Rp4", which have the largest difference in absolute values, are the points where the conflict should be resolved.

Further, as another method of setting the priority by the priority setting unit 15, a method of calculating the square of the undelivered amount by multiplying the degree of influence will be described. As shown in FIG. 7, it is assumed that the required performance "A" has a margin amount of 1, so the unachieved amount is 0, and the required performance "G" has an unachieved amount of 2. The priority order setting unit 15 determines that, among the contradiction points specified by the contradiction part identification unit 14, the part having the largest calculated value is the contradiction part to be eliminated.

Here, for example, the value of "Rp1" is -8, which is the product of -2 of the degree of influence and 4 which is the square of (-2), which is the square of the unachieved amount, and "Rp4" is the degree of influence. 5 and 4 of the square of (-2), which is the square of the undelivered amount, is multiplied by 20. Therefore, the size of the contradictory of "Rp1" and "Rp4" is 28. Similarly, the size of the contradiction between "Rp2" and "Rp4" is 28, and the size of the contradiction between "Rp3" and "Rp4" is 28. Here, the priority setting unit 15 can determine that the portion having a large calculated contradiction is a contradiction to be eliminated, but the calculated contradiction size is all as shown in this example. If the values are the same, it is determined that there is no need to resolve the conflict with a pass with an undelivered amount of 0. That is, since there is a path with an unachieved amount of 0 at the points related to "Rp2" and "Rp3" regarding the degree of influence from the required performance A side, the combination of "Rp2" and "Rp4" and "Rp3" and "Rp4" Is excluded, and the priority setting unit 15 determines that "Rp1" and "Rp4" are the places where the conflict should be resolved.

The display unit 16 can display the contradictions specified by the contradiction location specifying unit 14 and the priority of the contradictions determined by the priority setting unit 15.

Next, with reference to FIG. 8, a procedure for performing prioritization using the prioritization device 1 will be described.

The design information input unit 11 inputs the design information (step S1). The design information input here is, for example, QFD table information as shown in FIG. The prioritizing device 1 reads the identification of the target range and the relationship between the design variables included therein and the required performance from the design information such as the QFD table input by the design information input unit 11.

The causal model extraction unit 13 extracts a causal model related to the design information input by the design information input unit 11 from the causal model DB 12 (step S2). As a result, in the prioritization device 1, a causal model including physical variables as shown in FIG. 3 is created, and if there is a branch in the path, the degree of influence is also distributed.

The contradiction location specifying unit 14 identifies the contradiction portion in the causal model (step S3). That is, the contradiction location specifying unit 14 identifies contradiction locations between physical variables that are the root cause of impeding performance improvement. As a result, the contradiction location specifying portion 14 identifies that "Rp1" and "Rp4", "Rp2" and "Rp4", and "Rp3" and "Rp4" in FIG. 4 are contradiction locations, respectively.

The priority order setting unit 15 calculates the size of the contradiction and prioritizes the contradiction portion specified by the contradiction location specifying unit 14 (step S4). For the priority netting by the priority setting unit 15, either the method of using the margin amount and the unachieved amount of each required performance and the method of using the square of the unachieved amount can be used. The method is not limited to the above method, and other calculation methods may be used. As a result, the priority setting unit 15 can determine that the conflict between "Rp1" and "Rp4" in FIG. 5 should be resolved with priority.

The display unit 16 displays the contradiction portion determined by the priority order setting unit 15 to be preferentially resolved with respect to the contradiction portion specified by the contradiction location specifying unit 14 (step S5).

After resolving the contradictions with respect to the contradictions having a high priority (step S6), the prioritizing device 1 creates causal model information after the contradictions are resolved (step S7). Then, the prioritization device 1 stores the causal model information in the causal model DB 12 and accumulates the information (step S8).

After that, the process returns to step S2, and the prioritization device 1 can recalculate the priority of the contradictory points by repeatedly executing the same process using the causal model DB 12 after the information has been accumulated.

As a result, ranking can be easily performed for the contradictory points. That is, by quantifying the change in performance caused by the design change and having a distribution model for allocating the numerical value, it is possible to quantify each performance change caused by the design change. Therefore, even if there are a wide variety of design changes, it is possible to easily identify which part is the contradictory part by using numerical values.

The present invention can also be realized by causing a CPU (Central Processing Unit) to execute a computer program. In addition, the programs described above can be stored and supplied to a computer using various types of non-transitory computer readable media. Non-transient computer-readable media include various types of tangible storage media. Examples of non-temporary computer-readable media include magnetic recording media (eg, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (eg, magneto-optical disks), CD-ROMs (Read Only Memory) CD-Rs, CDs. -R / W, including semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (Random Access Memory)). The program may also be supplied to the computer by various types of temporary computer readable media. Examples of temporary computer-readable media include electrical, optical, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

The present invention is not limited to the above embodiment, and can be appropriately modified without departing from the spirit.

1 Prioritization device 11 Design information input unit 12 Causal model database (causal model DB)
13 Causal model extraction unit 14 Conflict location identification unit 15 Priority setting unit 16 Display unit

Claims (1)

It is equipped with a causal model DB that stores a causal model in which the design change location and the performance that changes due to the design change are associated in advance. A prioritization method that determines priorities,
The causal model stored in the causal model DB further includes an allocation model in which the total number of changes in each performance caused by a design change per unit is distributed as a numerical value of each performance change.
Based on the numerical value of the state change allocated in the allocation model, the combination of the performance improved and the performance decreased due to the design change is specified, and the contradictory points are prioritized.
Prioritization method.

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