A Mapping Method from EBOM to PBOM Based on Process Flows

Abstract

The present invention discloses a mapping method from EBOM to PBOM based on a process flow. The method includes: traversing all nodes in the EBOM in sequence based on breadth-first search to obtain the hierarchical relationships, production types, and inherent attribute information of each component. Performing special component structure mapping rules on the components according to the production type to complete the structure mapping. Obtaining the constraint relationships between materials and processes, and between processes and processes in the process route, establishing a material-process constraint relationship matrix, and further performing process attribute extension on the hierarchical relationship after redefining the structure through a material-process matching algorithm to complete the process attribute derivative mapping. Finally, constructing the PBOM according to the BOM assembly rules for the complete assembly relationship set of PBOM components to complete the complete mapping process. The present invention clarifies the relationship between materials and the process flow, and optimizes the intelligent matching between materials and processes.

Description

Technical Field

[0001] The present invention relates to the fields of process design and information management, and particularly relates to a mapping method from EBOM to PBOM based on process flow. Background Art

[0002] The Bill of Materials (BOM) is currently the core of an enterprise's product data management system, running through all product life cycles, and mainly consists of two parts: the structural hierarchical relationship of components and their natural attributes. The structural hierarchical relationship describes the compositional dependencies and transformation forms of product components, and is the organizational framework supporting the entire BOM; the natural attributes describe the production conditions and control factors of each component, and design attributes, process attributes, manufacturing attributes, cost attributes, etc. can be added or transformed according to the needs of each department. Currently, research on multi-view mapping of BOM mostly focuses on the transformation of the structural hierarchical relationship, and only a few scholars have defined basic attribute mapping types. For example, Chinese authorized patent publication (announcement) number CN111612686A only provides a structural mapping method from EBOM to PBOM; Yan Jinjin et al. pointed out in "Research on the Structural Mapping Method of BOM Multi-views" that attribute mapping only needs to appropriately add or delete attribute information; Huang Xuewen et al. focused on describing the transformation of component assembly relationships in "Research on the Mapping Model between BOM Multi-views and Views", and did not elaborate on how to obtain attribute information by querying process documents; Sun Hongxia, in "Research on the BOM Multi-view Mapping Model for Shipbuilding Processes", summarized a relatively complete set of attribute mapping types based on structural mapping types, and designed a complete BOM multi-view mapping algorithm for BOM attributes and structural mapping using set theory.

[0003] The Process BOM (PBOM) is one of the many transformation forms of the Bill of Materials. Based on the assembly relationship of the Engineering BOM (EBOM), it reconstructs the structural hierarchical relationship more from a process perspective, and adds process attribute information in combination with the product process route. Due to the lack of standard quantification of the dual constraint relationship between process route materials and processes, and between processes and processes, as well as a unified process attribute derivation rule in actual design and production, the instability of the BOM is further increased. Therefore, it is necessary to separately design a mapping method from EBOM to PBOM based on process flow to ensure the accurate and automatic mapping of the Bill of Materials. Summary of the Invention

[0004] Aiming at the deficiencies in the prior art, the present invention provides a mapping method from EBOM to PBOM based on process flow. While reconstructing the PBOM assembly relationship structure, it follows the process route to complete the automatic matching of materials and processes, realizing the dual mapping of structure and process attributes.

[0005] The present invention is achieved by the following technical means: A mapping method from EBOM to PBOM based on process flow, the method comprising:

[0006] Step 1: Based on breadth-first, traverse all nodes in the EBOM structure tree in sequence to obtain the hierarchical relationship L of each component, the production type attribute k i and inherent attribute information g such as material code, name, version, specification dimensions, etc. i ;

[0007] The hierarchical relationship L of the component is:

[0008] L = (f, s, e, v), f, s ∈ C, e ∈ N + (1)

[0009] Wherein, f is the parent part code, s is the child part code, e is the assembly quantity of the child part s under the current parent part f, and v is the level of the current child part in the structure tree, represented as L and L in EBOM and PBOM respectively P ;

[0010] Step 2: Judge the production type attribute k of the current component i , k i = 0, 1, 2, 3, 4, 1 - 4 respectively correspond to split parts, combined parts, inherited parts and outsourced parts, 0 corresponds to the product itself; according to the judgment result, execute the corresponding structure mapping rule on the hierarchical relationship L of the component, and output the redefined PBOM component hierarchical relationship L P , completing the structure mapping;

[0011] The structure mapping rule of the combined part is:

[0012] If the component needs to be recombined in the PBOM to form a new combined part according to the process flow, the structure relationship of the components involved in the PBOM needs to be modified, that is, the structure relationship between the nodes involved and the original parent part is released, and they are rearranged as child nodes and a new parent node is added, including two cases of same-level combination and cross-level combination, which are described as shown in formula (2):

[0013] And k j,k = 2, c j,k is the lower-level child part of c i , c h is the parent part of c i , there is:

[0014]

[0015] Wherein, the product component c iThe set of (i = 1, 2, …, m) is C, which is represented as C E and C P in EBOM and PBOM respectively. L ij represents the hierarchical relationship between c i and c j . L ik and L hi are similar. S L and represent the sets of L and L P respectively. f P (i) and f E (j) represent taking the parent part of c i in PBOM and the parent part of c j in EBOM respectively. v E (j) and v P (i) represent taking the hierarchy of c j in EBOM and the hierarchy of c i in PBOM respectively. "Up / down combination" means that in the case of cross-level combination, the hierarchical change of most sub-parts of the new parent part is that the hierarchy decreases for upward and increases for downward. k j,k represents the production type attribute of c j and c k . K represents the set of k i (i = 1, 2, …, m);

[0016] Step 3: Obtain the constraints between materials and processes, and between processes in the process route, and establish a material-process constraint relationship matrix R;

[0017] The specific form of the material-process constraint relationship matrix R (m+1)×n is as follows:

[0018]

[0019] where n is the number of processes required for product processing, m is the number of types of materials required for product processing, r ij is the quantity quota of material p j required for the normal progress of process w i . r ij ≥0, r′ (m+1)j is the number of the immediate successor process of process w j . If r′ (m+1)j = 0, it means that there is no immediate successor process for the last process in the process route.

[0020] Step 4: Based on the material-process constraint relationship matrix R, through the material-process matching algorithm, perform process attribute extension on the hierarchical relationship L P of the PBOM components after structural redefinition, and add the dependent previous process Wpre , the assembly process w and the subsequent process w back , output the complete assembly relationship PP of the PBOM parts, and complete the derivation mapping of process attributes;

[0021] The specific implementation steps of the material-process matching algorithm are as follows:

[0022] STEP1: Extract the current part c i and the set of sibling parts c and their respective assembly quantities e under the same parent part:

[0023] C ib = {(c1,e1),(c2,e2),(c3,e3)...};

[0024] STEP2: Find the non-zero columns in the row where the current part c i is located in R to form the set of relevant process materials:

[0025]

[0026] STEP3: Traverse the set of relevant process materials and judge whether the materials {p1,p2,p3...} occupied by each w j process are included in {c1,c2,c3...} and {r 1j ,r 2j ,r 3j ...} is ≤ {e1,e2,e3...}, j ≤ s < n. If so, end the traversal and jump to STEP4; otherwise, repeat STEP3;

[0027] STEP4: Record the current process w j (j ≤ s < n) and are the assembly process w and the subsequent process w back respectively. Traverse the row vector of the constraint relationship matrix r′ (m+1) to obtain the set of dependent prior processes W pre = {w l …|r′ (m+1)l = j, l < j};

[0028] STEP5: Expand the hierarchical relationship L P of process attribute information, including dependent prior processes, assembly processes and subsequent processes, complete the matching of parts and process routes, and obtain the complete assembly relationship PP of parts = (f,e,m,v,W pre ,w,w back );

[0029] Step Five: The set S of the complete assembly relationships of PBOM parts PPConstruct the PBOM according to the BOM structure correspondence rules to complete the entire mapping process from EBOM to PBOM.

[0030] The beneficial effects of the present invention are as follows:

[0031] Based on the existing technology, the present invention defines outsourced parts, split parts, assembled parts, inherited parts and related structure mapping rules, expresses the dual constraint relationships between materials and processes and between processes and processes in the product process route in the form of a constraint relationship matrix, and expands the process attribute information of the hierarchical relationship of parts through a material-process matching algorithm, realizing the dual conversion of the EBOM to the PBOM structure and process attributes, and driving and guiding the collaborative work of the entire product life cycle with the process flow. Description of the Drawings

[0032] Figure 1 It is the overall flowchart of the present invention.

[0033] Figure 2 It is the structure mapping process diagram from EBOM to PBOM in the embodiment of the present invention.

[0034] Figure 3 It is the directed graph of process relationships in the embodiment of the present invention.

[0035] Figure 4 It is the flowchart of the material-process matching algorithm in the embodiment of the present invention. Detailed Embodiments

[0036] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0037] According to an embodiment of the present invention, a method for mapping EBOM to PBOM based on a process flow is provided. It should be noted that the specific implementation details in the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention.

[0038] Since the BOM is a data form of the product structure, usually a tree-like organization form, this organization form runs through the entire product life cycle and reflects the parent-child relationship of parts at each stage of the product. For the convenience of describing the data structure and attribute information in the BOM below, the following definitions are first introduced:

[0039] (1) The set of product parts c i (i = 1, 2,..., m) is C, which is respectively represented as C E (c E i ) and C P (c P i ) in the EBOM and PBOM;

[0040] (2) Quadruple of component hierarchical relationship:

[0041] L = (f, s, e, v), f, s ∈ C, e ∈ N + (1)

[0042] Among them, f is the parent part code, s is the child part code, e is the assembly quantity of the child part s under the current parent part f, and v is the level of the current child part in the structure tree, which are represented as L and L in EBOM and PBOM respectively P ;

[0043] (3) EBOM quadruple:

[0044] B E = (C E , S L , K, G) (2)

[0045] Among them, C E is the set of components c E i in EBOM, S L is the set of component hierarchical relationship L in EBOM, K is the set of component production type attributes k i (i = 1, 2,..., m), and G is the set of component inherent attribute key-value pairs g i (i = 1, 2,..., m), including material code, name, version, specification size, etc.

[0046] (4) Seven-tuple of complete component assembly relationship:

[0047] PP = (f, s, e, v, W pre , w, w back ), f, s ∈ C p , e ∈ N + , W pre , w, w back ∈ Q (3)

[0048] Among them, W pre is the set of dependent previous processes, w is the assembly process, and w back is the subsequent process.

[0049] (5) PBOM five-tuple:

[0050] B P = (C P , S PP , K, G, Q) (4)

[0051] Among them, C P is the set of components c P iSet, S PP is the set of complete assembly relationships PP of components, and Q is the required process w of the product j (j = 1, 2, …, n).

[0052] Such as Figure 1 shown, is a flowchart of a mapping method from EBOM to PBOM based on process flow in an embodiment of the present invention, including the following steps:

[0053] Step 1: Based on breadth - first, traverse all nodes in the EBOM structure tree in sequence to obtain the hierarchical relationship L of each component, the production type attribute k i and inherent attribute information g such as material code, name, version, specification size, etc i .

[0054] Step 2: Judge the current production type attribute k of the component i , where 1 - 4 correspond to split parts, assembled parts, inherited parts, and outsourced parts respectively, and 0 corresponds to the product itself. According to the judgment result, execute the corresponding structure mapping rule on the hierarchical relationship L of the component, and output the re - defined PBOM component hierarchical relationship L P , completing the structure mapping.

[0055] In the BOM structure mapping problem, currently most research focuses on the conversion process from EBOM to Manufacturing BOM (MBOM), and there is little detailed analysis of the transformation form from EBOM to PBOM. The present invention establishes a corresponding mathematical model for the mapping rules of each special part on the basis of identifying special material types in the process of mapping from EBOM to PBOM, and establishes a structure mapping template library based on existing product mapping processing experience. If there is no corresponding processing template in the library, the conversion needs to be completed through human - machine interaction according to the mapping rules.

[0056] By analyzing the content and characteristics of the BOM views in the two stages of product design and process, it is determined that split parts, assembled parts, inherited parts, and outsourced parts are special parts in the mapping process. A split part refers to a part that is split into several sub - components in the EBOM due to processing method limitations; an assembled part refers to a new part formed by recombining several different components in the EBOM in the PBOM according to the process flow; an inherited part refers to a component whose structure information remains consistent during the mapping process; an outsourced part refers to a part whose body and subordinate components need to be processed outsourced, which has nothing to do with actual production and assembly, and the specific structure needs to be filtered in the PBOM.

[0057] Define the mapping rule f of split parts s as: If a certain component is a split part, then its subordinate components need to be reflected in the PBOM, that is, several sub - nodes are added under this node, and its mathematical description is shown in formula (5).

[0058] And k i =1,c j c i The subordinate components of

[0059]

[0060] Among them, v(j) is the number of components c. j level.

[0061] Split-piece mapping rule f s The corresponding algorithm process is:

[0062] STEP1: If the current component production type attribute k i =1, then split this piece c i And its level information is pushed into the stack parts_stack;

[0063] STEP2: When parts_stack is not empty, pop an element from it and assign it to parts, otherwise the mapping process ends;

[0064] STEP3: Find all sub-components c of parts in the structure mapping template library j , including sub-component code and assembly quantity information, pushed into the stack childs_stack;

[0065] STEP4: When childs_stack is not empty, pop an element from it and assign it to childs, set the level of childs to the parts level plus 1, build the structural hierarchy relationship L that does not exist in EBOM, repeat STEP4, otherwise go to STEP2.

[0066] Define assembly mapping rules f c If several parts need to be reassembled in PBOM to form a new assembly according to the process flow, the structural relationship of the involved parts in PBOM needs to be modified, that is, the structural relationship between the involved nodes and the original parent parts is released, and the nodes are rearranged as child nodes and new parent nodes are added. This mainly includes the same-level combination and cross-level combination. The mathematical description is shown in formula (6).

[0067] And k j,k =2,c j,k c i The lower level component, c h c i The parent of

[0068]

[0069] Among them, f(j) is the component cj Parent part

[0070] Assembly mapping rule f c The corresponding algorithm process is as follows:

[0071] STEP1: If the current part production type attribute k j = 2, then push this assembly c j and its part hierarchy relationship quadruple onto the stack parts_stack;

[0072] STEP2: When parts_stack is not empty, pop an element from it and assign it to parts, otherwise the mapping process ends;

[0073] STEP3: Search in parts_stack for the assembly c k corresponding to parts according to the structure mapping template library, including the part hierarchy relationship quadruple, and push it onto the stack bros_stack;

[0074] STEP4: When bros_stack is not empty, pop an element from it and assign it to bros, set the new common parent part of parts and bro_s in PBOM to father_new, corresponding to the part c i , modify the parent part code of parts and bro_s to the father_new code, otherwise go to STEP2;

[0075] STEP5: Determine the part c h of father_new in PBOM, construct the structure hierarchy relationship L hi that does not exist in EBOM, modify the levels of parts and bro_s to the level of father_new plus 1, and go to STEP4.

[0076] Define the inheritance part mapping rule f i as: If a certain part is an inheritance part, then there is no need to change its body and subordinate parts in PBOM, that is, the node structure relationship remains unchanged, and its mathematical description is shown in Equation (7).

[0077] And k i = 3, c j is the lower-level sub-part of c i , there is

[0078]

[0079] Define the outsourcing part mapping rule f aThat is: if a component is an outsourced component, its subordinate components will no longer be reflected in the PBOM, that is, all child nodes of this node will be deleted, and its mathematical description is shown in Equation (8).

[0080] And k i = 4, c j is the lower-level sub-component of c i and there are

[0081]

[0082] Due to the relatively simple mapping rules f i and f a for inherited components and outsourced components, the corresponding algorithms will not be elaborated here.

[0083] Figure 2 is the structure mapping process diagram from the EBOM to the PBOM in the embodiment of the present invention. In the EBOM, the component set C E = {P, A, B, C, D, E, F, G, C1, C2}, and the four-tuple representing the hierarchical relationship between the product P and the component C can be expressed as L 14 = (P, C, 2, 1). By analogy, the component hierarchical relationship set can be expressed as S L = {(P, A, 3, 1), (P, B, 1, 1), (P, C, 2, 1), (P, D, 1, 1), (P, E, 2, 1), (B, F, 3, 2), (B, G, 1, 2), (C, C1, 1, 2), (C, C2, 3, 2)}, K = {0, 1, 3, 4, 3, 2, 3, 2, 4, 4}. Together with the inherent attributes of each component, the four-tuple B E = (C E , S L , K, G) can completely represent the information contained in the EBOM.

[0084] For the split component A, 3 new structural hierarchical relationships L P are respectively (A, A1, 2, 2), (A, A2, 4, 2), (A, A3, 1, 2); for the outsourced component C, the child nodes C1, C2 and the structural hierarchical relationships (C, C1, 1, 2), (C, C2, 3, 2) are deleted; for the combined components G and E, the new parent component GE has B as the parent component, which is a cross-level downward combination. The structural hierarchical relationships L P of G and E are modified to be (GE, G, 1, 3) and (GE, E, 2, 3) respectively, and the structural hierarchical relationship L P of GE is added as (B, GE, 1, 2); the structural hierarchical relationships of the remaining inherited components remain unchanged.

[0085] After the structure mapping, the PBOM component set C P={P, A, B, C, D, A1, A2, A3, F, G, E, K and G are modified accordingly as the components increase or decrease (for the special production types involved in the conversion of PBOM to MBOM in K, separate definitions are required). At this time, the quadruple can fully represent the information contained in the current PBOM.

[0086] Step 3: Obtain the constraint relationships between materials and processes, and between processes and processes in the process route. After sorting, establish the material-process constraint relationship matrix R.

[0087] BOM mapping includes structure mapping and attribute mapping. During the conversion from EBOM to PBOM, in addition to reconstructing the component structure hierarchy according to the process separation surface, more importantly, process attribute information such as processing procedures, material quotas, man-hour quotas, and lead times is added in combination with enterprise production configuration and product process routes. Currently, process personnel often manually add process information based on experience. After obtaining the process route, it is necessary to consider the dual constraint relationships of materials on processes and processes on processes to improve the accuracy of the matching between PBOM materials and processes.

[0088] If processing a certain product requires N processes, the traditional process constraint relationship matrix is usually an N-order matrix, which quantitatively represents the precedence constraint information with 0-1. However, because PBOM needs to associate components with process data and material quotas, the present invention simultaneously considers the two constraints of materials and processes, constructs a material-process constraint relationship matrix based on the process route, and lays the foundation for the accurate matching of materials and processes. Different process routes result in different constraint relationship matrices. To facilitate the description of the establishment process of the material-process constraint relationship matrix in the present invention and related content in subsequent methods, the following symbolic variables are introduced:

[0089] R: Represents the material-process constraint relationship matrix corresponding to the selected process route of the current product;

[0090] n: Represents the number of processes required for product processing;

[0091] m: Represents the number of types of materials required for product processing (excluding the product itself);

[0092] p i : Represents the i-th material required for product processing, 0 < i ≤ m;

[0093] w j : Represents the j-th process for product processing, 0 < j ≤ n;

[0094] r ij : Represents the quantity quota of the material p j required for the normal progress of the process w i rij ≥ 0;

[0095] r' (m+1)j : represents the serial number of the immediate successor process of process w j If r' (m+1)j = 0, it means that there is no immediate successor process for the last process in the process route.

[0096] The material - process constraint relationship matrix R is shown in Equation (9). After selecting the production process route of the current product, an (m + 1) × n - order matrix is constructed. Horizontally, it represents process w j , and vertically, it represents material p i . By traversing the non - zero values in each column, the types and quotas of materials required for process w j can be obtained. By traversing the non - zero values in each row, the processes involved in material p i can be obtained. The r' (m+1) row vector represents the immediate successor process of each process w j . Each process can only have one subsequent process, and the entire process route can only end in one process. In this way, the precedence relationship between product processes and the corresponding relationship between processes and materials can be completely determined.

[0097]

[0098] Figure 3 is the directed graph of process relationships in the embodiment of the present invention, which characterizes the dependency relationship between product processes. The corresponding relationship between processes and materials is shown in Table 1.

[0099] Table 1 Corresponding relationship between processes and materials

[0100]

[0101] According to the above definitions and the precedence relationship between product processes and the corresponding relationship between processes and materials, the material - process constraint relationship matrix corresponding to the current process route can be established, as shown in Equation (10).

[0102]

[0103] Step 4: Based on the material - process constraint relationship matrix R, through the material - process matching algorithm, perform process attribute expansion on the hierarchical relationship L P of the PBOM components after re - definition of the structure, and add the dependent precedence process W pre , the assembly process w, and the immediate successor process w back , and output the complete assembly relationship PP of the PBOM components to complete the derivative mapping of process attributes.

[0104] The material - process constraint relation matrix R is the basis for the expansion of the process information of PBOM components. The following presents the material - process matching algorithm to help the process information of product components be automatically and accurately associated. Figure 4 It is the flowchart of the material - process matching algorithm of the embodiment of the present invention.

[0105] STEP1: Extract the current component c i and its co - sibling components c and the set of assembly quantities e:

[0106] C ib ={(c1,e1),(c2,e2),(c3,e3)...};

[0107] STEP2: Find the non - zero columns in the row where the current component c i is located in R to form the set of relevant process materials

[0108]

[0109] STEP3: Traverse the set of relevant process materials, and judge whether the materials {p1,p2,p3…} occupied by each w j (j≤s<n) process are included in {c1,c2,c3…} and {r 1j ,r 2j ,r 3j …} is ≤ {e1,e2,e3…}. If so, end the traversal and jump to STEP4; otherwise, repeat STEP3;

[0110] STEP4: Record the current process w j (j≤s<n) and are the assembly process w and the immediate successor process w back respectively. Traverse the row vector of the constraint relation matrix r′ (m+1) to obtain the set of dependent prior processes W pre ={w l …|r′ (m+1)l =j,l<j};

[0111] STEP5: Expand the hierarchical relationship L P of the component process attribute information, including the dependent prior process, the assembly process, and the immediate successor process, complete the matching of the component and the process route, and obtain the complete assembly relationship of the component PP=(f,e,m,v,W pre ,w,w back ).

[0112] Taking Figure 2 and Figure 3 as examples, the set of component hierarchical relationships output in step 2 The material - process constraint relationship matrix established in step 3 is used as the input of the material - process matching algorithm to expand the process attributes of each component. For component A1, it and its sibling components with the same father together form set C 5b ={(A1, 2), (A2, 4), (A3, 1)}. The non - zero columns in the 5th row of the material - process constraint relationship matrix are 3, and the relevant process material set is

[0113] Because and {2, 4, 1} ≤ {2, 4, 1}, so record the current process w3 and as the assembly process and the immediate successor process respectively, traverse the constraint relationship matrix r′ (12) row vectors, and obtain the set of dependent precedence processes as The complete assembly relationship PP5 of component A1 after process attribute expansion can be expressed as And so on, the set S of complete assembly relationships of PBOM components PP can be expressed as:

[0114]

[0115] Step 5: Assemble the PBOM by organizing the set S of complete assembly relationships of PBOM components PP according to the BOM structure correspondence rules, and complete the complete mapping process from EBOM to PBOM.

[0116] The PBOM after structure mapping in step 2 has been represented by the quadruple After expanding the process attributes of L P , has been converted to S PP , and the current PBOM can be represented by B P =(C P , S PP , K, G, Q). In the PBOM, the processes are described by process numbers, and information such as material quota, man - hour quota, and lead time can be queried by associating with the process numbers, ensuring the consistency and accuracy of BOM information in the product life cycle and improving the BOM mapping efficiency.

Claims

1. A mapping method from EBOM to PBOM based on the process flow, the method comprising: Step 1: Based on breadth-first traversal, traverse all nodes in the EBOM structure tree in sequence to obtain the hierarchical relationship L of each component, the production type attribute k i and the inherent attribute information g of the material code, name, version, and specification size i ; The hierarchical relationship L of the parts is: L = (f, s, e, v), where f, s ∈ C and e ∈ N + (1) Among them, f is the parent part code, s is the child part code, e is the assembly quantity of the child part s under the current parent part f, and v is the level of the current child part in the structure tree, which is represented as L and L in the EBOM and PBOM respectively. P ; Step 2: Determine the production type attribute k of the current component i , k i = 0, 1, 2, 3, 4, where 1 - 4 respectively correspond to split parts, assembled parts, inherited parts, and outsourced parts, and 0 corresponds to the product itself; according to the determination result, perform the corresponding structure mapping rules on the component hierarchy relationship L, and output the re - defined PBOM component hierarchy relationship L P , and complete the structure mapping; The structure mapping rule of the sub-assembly is: If the parts need to be recombined in the PBOM to form a new sub-assembly according to the process flow, the structure relationship of the parts involved needs to be modified in the PBOM, that is, the structure relationship between the nodes involved and the original parent part is released, and they are rearranged as child nodes and a new parent node is added, including two cases of same-level combination and cross-level combination, which are described as shown in formula (2): and k j,k = 2, c j,k is the subordinate sub-component of c i and c h is the parent component of c i there is: Among them, product component c i (i = 1, 2, …, m) has a set C, which is represented as C E and C P in the EBOM and PBOM respectively. L ij represents the hierarchical relationship between c i and c j . L ik and L hi are similar. S L and S LP represent the sets of L and L P respectively. f P (i) and f E (j) represent taking the parent component of c i in the PBOM and the parent component of c j in the EBOM respectively. v E (j) and v P (i) represent taking the hierarchy of c j in the EBOM and the hierarchy of c i in the PBOM respectively. "Up / Down combination" means that in the case of cross-level combination, the hierarchical changes of most sub-components of the new parent component, with the hierarchy decreasing for upward and increasing for downward. k j,k represents the production type attribute of c j and c k . K represents the set of k i (i = 1, 2, …, m); Step Three: Obtain the constraint relationships between materials and processes, and between processes and processes in the process route, and establish a material-process constraint relationship matrix R; The material - process constraint relationship matrix R (m+1)×n is specifically expressed as: where n is the number of processes required for product processing, m is the number of types of materials required for product processing, and r ij is the quantity quota of material p j required for the normal progress of process w i , r ij ≥0, and r′ (m+1)j is the number of the immediate successor process of process w j . If r′ (m+1)j = 0, it means that there is no immediate successor process for the last process in the process route; Step 4: Based on the material - process constraint relationship matrix R, through the material - process matching algorithm, perform process attribute extension on the PBOM component hierarchy relationship L P after the structure is re - defined, adding the dependent preceding process W pre , the assembly process w, and the succeeding process w back , and output the complete assembly relationship PP of the PBOM components to complete the derivative mapping of process attributes; Step Five: The complete assembly relationship set S of PBOM components PP Construct the PBOM according to the corresponding rules of the BOM structure to complete the complete mapping process from EBOM to PBOM.

2. The mapping method from EBOM to PBOM based on a process flow as described in claim 1, wherein The specific implementation steps of the material-process matching algorithm in Step Four are: STEP1: Extract the current component c i and the set of sibling components c and their respective assembly quantities e under the same parent component: C ib = {(c1, e1), (c2, e2), (c3, e3)...}; STEP2: Locate the current component c i The non-zero columns of the row where it is located in R form the set of materials for related processes: STEP3: Traverse the set of materials for related processes and determine whether the materials {p1, p2, p3...} occupied by each j process are included in {c1, c2, c3...} and {r 1j , r 2j , r 3j ...} is ≤ {e1, e2, e3...}, where j ≤ s < n. If so, end the traversal and jump to STEP4; otherwise, repeat STEP3. STEP4: Record the current process w j (j ≤ s < n) and are the assembly process w and the subsequent process w respectively back , traverse the constraint relation matrix r′ (m+1) row vector, and obtain the set W of dependent preceding processes pre ={w l …|r′ (m+1)l = j, l < j}; STEP5 : Expand the hierarchical relationship L of parts P Process attribute information, including dependent previous processes, assembly processes, and subsequent processes, to complete the matching of parts and process routes, and obtain the complete assembly relationship PP = (f, e, m, v, W pre , w, w back ).

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