Method for calculating importance degree of functions in product function architecture

Abstract

The invention relates to the technical field of product design, and discloses a method for calculating the importance degree of functions in a product function architecture, which comprises the following steps of: carding logical relationships among states, modes and functions of a product, constructing a function distribution table, defining the importance degree of each state, and keeping the sum of the importance degrees of the states to be 1; according to the function distribution table and the series-parallel connection relation between the functions, function flow block diagrams FFBDs are constructed one by one with the state as the unit; and calculating the importance degree corresponding to each function contained in each state according to the series-parallel connection relationship of each function in the FFBD corresponding to each state and the importance degree corresponding to each state, and further obtaining the total importance degree of each function in all the states.

Description

Technical Field

[0001] The present invention relates to the technical field of product design, and particularly relates to a method for calculating the importance degree of functions in a product function architecture. Background Art

[0002] In the process of product design, the function architecture is the key link connecting the product design requirements and the product composition architecture, and is also the main embodiment of product design innovation. Different functions in the function architecture cooperate with each other and execute in an orderly manner to jointly complete specific upper-layer functions. In the function analysis stage of the product, several functions are combined in an orderly manner to make the product in a specific working state / mode, and a specific function may appear repeatedly in multiple working states / modes. Given that the participation degrees of different functions in the working state / mode are different, resulting in different importance degrees of functions. Therefore, how to calculate the importance degree of functions is very important for identifying key functions, reasonably allocating function indicators, and improving the quality of function design. Summary of the Invention

[0003] The present invention provides a method for calculating the importance degree of functions in a product function architecture, which can quickly identify key functions, provide a data basis for reasonably allocating function indicators, and thus improve the quality of function design.

[0004] The present invention can be realized through the following technical solutions:

[0005] A method for calculating the importance degree of functions in a product function architecture, comprising the following steps:

[0006] Step 1: Sort out the logical relationships among the states, modes, and functions of the product, construct a function distribution table, and define the importance degree of each state, and keep the sum of the importance degrees of all states as 1;

[0007] Step 2: According to the function distribution table and the series-parallel relationships among the functions, construct a function flow block diagram FFBD for each state one by one;

[0008] Step 3: According to the series-parallel relationships of the functions in the function flow block diagram FFBD corresponding to each state, and the importance degree corresponding to each state, calculate the importance degree corresponding to each function included in each state, and further obtain the total importance degree of each function in all states.

[0009] Furthermore, in the said Step 3, according to the function flow block diagram FFBD corresponding to each state, formulate an importance degree allocation rule according to the series-parallel relationships of the functions. First, allocate the importance degree of the functions by 100% according to the percentage, calculate the importance degree ratio of each function, and then obtain the preset importance degree ci of the corresponding state, and multiply the importance degree ci by the importance degree ratio of each function in this state to obtain the importance degree of each function in this state.

[0010] Furthermore, the importance assignment rules are formulated as follows:

[0011] According to the functional flow block diagram FFBD, if K adjacent functions are in series relationship, the importance levels corresponding to these functions are equal;

[0012] If K adjacent functions are in parallel relationship and all of these K functions must be executed before the subsequent function can be executed, the importance levels corresponding to these K functions are the same, and are the same as the importance levels corresponding to the preceding or subsequent functions in series / parallel;

[0013] If K adjacent functions are in parallel relationship and any one of these functions can execute the subsequent function after being executed, the importance levels corresponding to these K functions are the same, and are 1 / K of the importance levels corresponding to the preceding or subsequent functions in series / parallel;

[0014] where K≥2.

[0015] Furthermore, in the third step, if a state contains multiple identical functions, only the importance level corresponding to the first-occurring function is calculated.

[0016] Furthermore, in the third step, the importance levels of each function in all states are accumulated, and the obtained sum is the total importance level of the function.

[0017] Furthermore, the function distribution table is constructed with states and modes as column distributions and functions as row distributions, and the states, modes, and functions are all arranged in the order of the product's functional flow. Among them, the state is the first-level column distribution, the mode is the second-level column distribution, a state can include one or more modes, and if a function is put into operation in the corresponding state / mode, it is marked as 1, otherwise it is left blank.

[0018] The beneficial technical effects of the present invention are as follows:

[0019] In the process of product design, according to the logical relationship among states, modes, and functions, a function distribution table is constructed, and then the corresponding functional flow block diagram FFBD is constructed for each state based on the function distribution table, so as to calculate the total importance level distribution of each function in the whole product, providing an auxiliary tool to support designers to carry out efficient function analysis, helping designers quickly identify key functions, so as to more reasonably allocate function indicators and effectively improve the design quality of functions. Description of the Drawings

[0020] Figure 1 is the overall flow schematic diagram of the present invention;

[0021] Figure 2 is the schematic diagram of the functional flow block diagram FFBD constructed in series mode of the present invention;

[0022] Figure 3 Schematic diagram of the functional flow block diagram FFBD constructed in a concurrent-OR manner for the present invention;

[0023] Figure 4 Schematic diagram of the functional flow block diagram FFBD constructed in a concurrent-concurrent manner for the present invention;

[0024] Figure 5 Schematic diagram of the functional flow block diagram FFBD constructed in a concurrent-OR manner for the present invention with duplicate functions;

[0025] Figure 6 Schematic diagram of the functional flow block diagram FFBD constructed in a concurrent-concurrent manner for the present invention with duplicate functions;

[0026] Figure 7 FFBD diagram corresponding to product state 1 in a specific embodiment of the present invention;

[0027] Figure 8 FFBD diagram corresponding to product state 2 in a specific embodiment of the present invention. Detailed implementation manners

[0028] The following details the specific implementation manners of the present invention in conjunction with the accompanying drawings and preferred embodiments.

[0029] As Figure 1 shown, the present invention provides a method for calculating the importance degree of functions in a product function architecture. By sorting out the logical relationships among the states, modes, and functions of the product, a function distribution table is constructed, and the importance degree corresponding to each state is defined, with the sum of the importance degrees of all states being 1; according to the function distribution table and the series-parallel relationships among the functions, a functional flow block diagram FFBD is constructed one by one in units of states; according to the series-parallel relationships of the functions in the functional flow block diagram FFBD corresponding to each state, and the importance degree corresponding to each state, the importance degree corresponding to each function included in each state is calculated, and then the total importance degree of each function in all states is obtained. In this way, during the product design process, with the help of the function distribution table and the functional flow block diagram FFBD, the importance degree distribution of each function in the entire product is calculated, providing an auxiliary tool to support designers in carrying out efficient function analysis, helping designers quickly identify key functions, so as to reasonably allocate function indicators and effectively improve the design quality of functions.

[0030] Specifically as follows:

[0031] Step 1: Construct a function distribution table

[0032] Each function of the product is put into operation under specific states / modes. If a function is not used under all states / modes of the product operation, it means that the function is overdesigned and should be eliminated, that is, all product functions should be distributed under specific states / modes. By sorting out the logical relationships among the states, modes, and functions of the product, and according to whether the function runs and the number of runs under various states / modes of the product, during the product design process, a function distribution table is constructed to describe the logical relationship between the state / mode and the function. The structure of this table is shown in Table 1, and they are all arranged in the order of the product's function flow. Among them, the state is the first-level column distribution, the mode is the second-level column distribution, and one state can include one or more modes. If a certain function is put into operation under the corresponding state / mode, it is marked as 1 at the corresponding position in the table, otherwise it is left blank. At the same time, the importance corresponding to each state in the product is defined, and the sum of the importance of each state is kept as 1 to provide a basis for subsequent importance calculation.

[0033] Table 1 Product State / Mode Function Distribution Table

[0034]

[0035] Step 2: Construct a Function Flow Block Diagram FFBD for each state one by one

[0036] For the functions of the product, the logical relationships among the functions can be described by a Function Flow Block Diagram FFBD. This kind of diagram defines the hierarchical decomposition relationship of functions and the series and parallel execution logics among functions at the same level to describe the timing relationship of function operation. Figure 2 It means that the three functions F1, F2, and F3 of the product are executed in series.

[0037] Take Figure 2 F2 in as an example. Assume that the F2 function contains three sub-functions F2.1, F2.2, and F2.3. The three sub-functions are executed concurrently, and if any one of the sub-functions is executed, the function F2 is executed, that is, the concurrent-concurrent logical relationship. The function logic is defined as Figure 3 shown. If all three sub-functions F2.1, F2.2, and F2.3 must be executed before the function F2 is executed, that is, the concurrent-OR logical relationship. The function logic is defined as Figure 4 shown.

[0038] Step 3: Calculate the importance corresponding to each function included in each state

[0039] According to the function decomposition scheme under each state described by the FFBD, for the FFDB corresponding to each state, based on the following rules, the importance of each function in the FFBD is calculated subsequently:

[0040] If two or more functions have a serial logical relationship, the importance levels of these functions are equal, as shown by F1, F2, and F3 in Figure 2 ;

[0041] If two or more functions have a concurrent logical relationship and subsequent functions can only be executed after all functions have been completed, the importance levels of these functions are the same and are the same as the predecessors or successors of other functions connected in series / parallel. For example, as shown by F21, F22, and F23 in Figure 3 , the importance levels of F21, F22, and F23 are all equal to that of F1. That is, if there are k concurrent-concurrent functions in the figure, the importance levels of these k functions are the same;

[0042] Specifically, for the case where the function F1 as shown in Figure 5 repeatedly appears, although the importance level of F1 in the parallel position is the same as that of F1 in the series position at this time, only the importance level of the first F1 connected in series is calculated, and the importance level of F1 in the parallel structure is not calculated repeatedly.

[0043] If two or more functions have a concurrent logical relationship, but subsequent functions can be executed after any one of the functions is completed, the importance levels of these functions are all equal to the importance level of the predecessor or successor function divided by the number of concurrent functions. For example, as shown in Figure 4 , the importance levels of F21, F22, and F23 in the figure are 1 / 3 of that of F1. That is, if there are k concurrent-or functions in the figure, the importance levels of these functions are 1 / k of the importance level of the predecessor / successor function;

[0044] Specifically, for the case where the function F1 as shown in Figure 6 repeatedly appears, although the importance level of F1 at the position of F2 is half of that of F1 in the series position at this time, only the importance level of the first F1 connected in series is calculated, and the importance level of F1 in the parallel structure is not calculated repeatedly.

[0045] Similarly, for the case where the serial logical function F1 as shown in Figure 2 repeatedly appears, only the importance level of the first F1 connected in series is calculated, and the importance level of F1 in the parallel structure is not calculated repeatedly.

[0046] According to the above rules, first allocate the importance level of the function at 100%, calculate the importance level ratio of each function in each state, and then obtain the preset importance level ci for the corresponding state. Multiply the importance level ci by the importance level ratio of each function in that state to obtain the importance level of each function in that state.

[0047] Step 4: Calculate the total importance level of each function in all states

[0048] The importance level of a function is equal to the sum of the importance levels obtained for that function in all states, and the importance level of the function based on the percentage is obtained.

[0049] To verify the feasibility of the calculation method of the present invention, the following example is described in detail. The function distribution table of this example is shown in Table 2, and the importance of state 1 is set to 0.6, and the importance of state 2 is set to 0.4.

[0050] Table 2 Example of Function Distribution of Product States

[0051] Status 1 Status 2 Function 1 (F1) 1 Function 2 (F2) 1 Function 3 (F3) 1 1 Function 4 (F4) 1

[0052] Correspondingly, the FFBD diagrams of the functions in states 1 and 2 are shown in Figures 7 and 8 respectively.

[0053] According to the aforementioned importance calculation process, for the FFBD diagram of state 1, F1 and F3 are in series, indicating that the importance of F1 and F3 is the same. According to the rule mentioned in step three of the above method, when the importance is allocated according to 100%, the importance of F1 and F3 each accounts for half, both being 50%; then, since the importance of state 1 is 0.6, the importance of each function in this state is:

[0054] The importance of F1 is: 50% × 0.6 = 0.3;

[0055] The importance of F3 is: 50% × 0.6 = 0.3;

[0056] For the FFBD diagram of state 2, it can be seen that the importance of F2, F3, and F4 is the same, that is, when the importance is allocated according to 100%, the importance of F2, F3, and F4 each accounts for 1 / 3 (about 33.3%). Since the importance of state 2 is 0.4, the importance of each function in this state is:

[0057] The importance of F2 is: 1 / 3 × 0.4 ≈ 0.1332;

[0058] The importance of F3 is: 1 / 3 × 0.4 ≈ 0.1332;

[0059] The importance of F4 is: 1 / 3 × 0.4 ≈ 0.1332;

[0060] In summary, the total importance of each function is equal to the sum of the importance of the function in all states, and there is:

[0061] The importance of F! is: the importance of F1 in state 1 + the importance of F1 in state 2 = 0.3 + 0 = 30%

[0062] The importance of F2 is: the importance of F2 in state 1 + the importance of F2 in state 2 = 0 + 0.1332 = 13.32%

[0063] The importance of F3 is: the importance of F3 in state 1 + the importance of F3 in state 2 = 0.3 + 0.1332 = 43.32%

[0064] The importance of F4 is: the importance of F4 in state 1 + the importance of F4 in state 2 = 0 + 0.1332 = 13.32%. Although the specific embodiments of the present invention are described above, those skilled in the art should understand that these are only examples. Without departing from the principles and essence of the present invention, various changes or modifications can be made to these embodiments. Therefore, the protection scope of the present invention is defined by the appended claims.

Claims

1. A method for calculating the importance degree of functions in a product function architecture, characterized in that It includes the following steps: Step 1: Sort out the logical relationships among the states, modes, and functions of the product, construct a function distribution table, and define the importance of each state, with the sum of the importance of all states being 1; Step 2: According to the function distribution table and the series-parallel relationships among the functions, construct a function flow block diagram FFBD for each state one by one; Step 3: According to the series-parallel relationships of the functions in the function flow block diagram FFBD corresponding to each state and the importance corresponding to each state, calculate the importance corresponding to each function included in each state, and then obtain the total importance of each function in all states.

2. The calculation method of the importance degree of functions in the product function architecture according to claim 1, wherein: In Step 3, according to the function flow block diagram FFBD corresponding to each state, formulate an importance distribution rule according to the series-parallel relationships of the functions. First, distribute the importance of the functions at 100%, calculate the importance ratio of each function, and then obtain the preset importance ci of the corresponding state. Multiply the importance ci by the importance ratio of each function in this state to obtain the importance of each function in this state.

3. The calculation method of the importance degree of functions in the product function architecture according to claim 2, characterized in that Formulate the importance distribution rule in the following way: According to the function flow block diagram FFBD, if K adjacent functions are in series relationship, the importance corresponding to these functions is equal; If K adjacent functions are in parallel relationship and all these K functions must be executed before the subsequent function can be executed, the importance corresponding to these K functions is the same, and is the same as the importance corresponding to the previous or subsequent function in series / parallel connection; If K adjacent functions are in parallel relationship and any one of these functions can be executed to execute the subsequent function, the importance corresponding to these K functions is the same, and is 1 / K of the importance corresponding to the previous or subsequent function in series / parallel connection; where K≥2.

4. The calculation method of the importance degree of functions in the product function architecture according to claim 3, characterized in that: In Step 3, if a state contains multiple identical functions, only calculate the importance corresponding to the function that appears first.

5. The calculation method of the importance degree of functions in the product function architecture according to claim 1, wherein: In Step 3, accumulate the importance of each function in all states, and the obtained sum is the total importance of the function.

6. The calculation method of the importance degree of functions in the product function architecture according to claim 1, wherein: The function distribution table is constructed with states and modes as column distributions and functions as row distributions, and the states, modes, and functions are all arranged in the order of the product's function process. Among them, the state is the first-level column distribution, the mode is the second-level column distribution, a state can include one or more modes. If a function is put into operation in the corresponding state / mode, it is marked as 1, otherwise it is left blank.

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