A device whole life cycle maintenance activity graph model construction method

Abstract

The application discloses a device whole life cycle maintenance activity graph model construction method, which comprises the following steps: step one, construction of a graph model meta-model based on an event-state triggering mechanism; step two, initialization configuration of a specific model device graph model based on a BOM; and step three, management and tracking of maintenance activities by running and dynamically updating the device maintenance graph model; the application comprehensively applies the event-state triggering mechanism and a maintenance activity formalization method based on set theory and relational algebra, supports intuitive visualization of human device maintenance activities, supports deployment to a computer for reading, writing and dynamic updating of the device maintenance activities, helps device users to realize computer-aided maintenance of the device, and more conveniently manages and tracks the maintenance activities of the device; the application reduces the failure frequency of the device, reduces production cost, and improves enterprise profit.

Description

Technical Field

[0001] This invention belongs to the field of equipment maintenance technology, and specifically relates to a method for constructing a graphical model of equipment's full life cycle maintenance activities. Technical Background

[0002] The condition of equipment directly impacts a company's production efficiency and product quality, and equipment maintenance costs are increasingly becoming a key factor affecting company profits. Therefore, reducing equipment failure frequency and maintenance costs has become a crucial issue for businesses. Current research on equipment maintenance focuses primarily on fault diagnosis; however, fault diagnosis alone cannot fully meet the actual needs of companies. Proactive maintenance and manual inspections cannot be completely replaced, and sudden equipment failures cannot be entirely avoided. Therefore, companies often employ multiple strategies simultaneously, including periodic proactive maintenance, condition-based maintenance based on manual inspections, condition-based maintenance based on digital monitoring, and post-failure maintenance. Periodic proactive maintenance is the most widely used strategy in actual production, and its implementation relies heavily on guidance from equipment manufacturers. However, most proactive maintenance plans provided by equipment manufacturers are presented in paper manuals and simply listed as maintenance items, which cannot be directly applied to computer-aided maintenance (CAM) and hinders its implementation. The management and tracking of the other three maintenance activities also typically rely on paper forms or simple dispatch systems lacking industrial mechanisms, failing to enable computer-based reading, writing, and dynamic updates of maintenance activities throughout the equipment's lifecycle.

[0003] Patent CN102982430B discloses a graphical modeling method for real-time tracking of work-in-process logistics using RFID. This method involves granular decomposition and evolution of the process flow using graphical modeling, enabling RFID configuration for each process flow as needed. By configuring four state block graphical description units, abstracted from the RFID signal detection space, onto the process flow, a graphical representation of the RFID-configured process flow is achieved. Then, based on the state set of work-in-process obtained from the state description units, a mapping relationship between state pairs and events is established, realizing the transformation from state set to event set. Finally, an event-driven graphical description unit model is established, and the generated event set is used to connect several consecutive graphical description units, thus achieving a graphical description for work-in-process tracking. However, this patent is only applicable to real-time tracking of work-in-process logistics and cannot track and manage maintenance activities throughout the entire equipment lifecycle. Therefore, enterprises urgently need a management and control model for equipment maintenance activities to systematically manage and track equipment maintenance activities using computers. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the present invention aims to provide a method for constructing a graphical model of equipment lifecycle maintenance activities. This method comprehensively applies an "event-state" triggering mechanism and a formalization method for maintenance activities based on set theory and relational algebra. It not only supports intuitive visualization of equipment maintenance activities for humans, but also supports deployment on computers for reading, writing, and dynamic updating of equipment maintenance activities. This helps equipment users achieve computer-aided maintenance of equipment and makes it easier to manage and track equipment maintenance activities.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for constructing a graphical model of equipment lifecycle maintenance activities includes the following steps:

[0007] Step 1: Construction of the graph model metamodel based on the "event-state" triggering mechanism

[0008] Equipment maintenance activities are divided into four types of maintenance activity blocks, described using different colors and shapes. These activity blocks are represented as follows:

[0009] MAB::={TBM, ICBM, DCBM, BM}

[0010]

[0011] MAB describes the equipment maintenance activities, where S... i Represents the state of the activity; Start Event E start and the end event E end These represent the start and end of the maintenance activity, respectively; t start and t end They are E start and E end The time of occurrence, i.e., the start and end times of the maintenance activity; the component requiring maintenance is denoted as P; the worker performing the maintenance is denoted as W; F info This represents the fault information for the maintenance activity; M info This indicates specific maintenance information, defined in detail below:

[0012]

[0013] In the formula, phenomenon is the fault symptom recorded during the detection phase; reason is the fault cause discovered during the identification phase; tool is the required spare parts and tools; method represents the maintenance method; tool and method are in F info The middle represents the recommended solution for the decision-making stage, while the middle represents the solution recommended for the decision-making stage. info The middle part represents the actual solution used;

[0014] Since TBM activity blocks are planned before execution, TBM modes are divided into three types: planned, executed, and overdue; planned represents the end event of a TBM activity block. The end event E of the TBM activity block when it has been executed end =ME; The end event E of the TBM activity block after it has expired. end =0 indicates that the planned maintenance period for the equipment has expired;

[0015] The equipment maintenance diagram model describes all maintenance activities throughout the entire process of equipment from installation to decommissioning. It is represented as a timeline with maintenance activity blocks inserted, as shown below:

[0016] MGM::={MAB1, MAB2,…,MAB n} (5)

[0017] Using relational algebra theory, it can be expressed as:

[0018] MGM(id, S, E_start, E_end, t_start, t_end, part_id, w_id,

[0019] phenomenon, reason, tool_f, method_f, tool_m, method_m) (6)

[0020] MAB considers it to be a tuple of MGM, that is:

[0021] MAB i ∈MGM

[0022] MAB i = <id i S i E_start i E_end i t_start i t_end i part_id i w_id i (7). phenomenon i reason i tool_f i method_f i ,tool_m i method_m i >

[0023] Step 2: Initialize and configure the schematic model of the specific device based on the BOM.

[0024] The initial maintenance diagram model of a device is generated using BOM theory, including the following four steps:

[0025] 2.1 Construct a general design BOM describing a series of similar devices;

[0026] The generic design BOM contains all the components of this product series. According to graph theory, the generic design BOM can be represented as a tree, i.e.:

[0027] GEBOM = (P, A)

[0028] P = {e, p1, p2, ..., p} n}

[0029] A = {a1, a2, ..., a} m} (8)

[0030] In the formula, P represents parts and components; A represents the assembly relationship of parts; e represents equipment, i.e., the root node of the general design BOM tree; p i This represents a part or component; if it has no child nodes, it is a part; otherwise, it is a component. i This indicates assembly relationships; specific components can be represented as follows:

[0031] p i ={id i name i type i MD i} (9)

[0032] In the formula, id i Indicates the part or component number; name i Indicates name; type i Indicate whether it is a purchased part, a self-made part, or a standard part; MD i Different models of parts are indicated as follows:

[0033] MD i ={model1,model2,…,model n} (10)

[0034] model i ={id i name i code i detail i} (11)

[0035] In the formula, id i The model number; name i Indicates the model name; code iModel code representing the model; detail i Other information representing the model;

[0036] Assembly relationships can also be represented as node pairs, i.e.:

[0037] a j = <p k p l > (12)

[0038] 2.2 Summarize the contents of the proactive maintenance plan and add them to the general design BOM to build a general maintenance BOM for a series of similar equipment;

[0039] The general maintenance BOM is represented as follows:

[0040] GMBOM = (P, A)

[0041] P = {e, p1, p1, ..., p} n}

[0042] A = {a1, a1, ..., a1} m} (13)

[0043] A component may have multiple active maintenance items. PM is used to represent the active maintenance items of a part or component:

[0044] PM i ={pm1, pm2, ..., pm n}

[0045] pm i ={name i tool i method i period i} (14)

[0046] In the formula, pm i This represents each specific item of proactive maintenance; name i Indicates the name of the content to be actively maintained; tool i Indicates the maintenance tool used; method i Indicates the maintenance method; period i Indicates the maintenance cycle;

[0047] Associate proactive maintenance content with a specific model of component:

[0048] model i ={id i name i code i detaili PM i} (15)

[0049] To facilitate computer programming, the general design BOM uses relational algebra representation:

[0050] GEBOM(part_id, parent_id, name, typemodel_id, model_name, model_code, model_detail) (16)

[0051] Active maintenance projects can be represented as:

[0052] PM(model_id, pm_id, pm_name, pm_tool, pm_method, pm_period) (17)

[0053] Therefore, the general maintenance BOM can be represented as:

[0054]

[0055] in, The natural join symbol in relational algebra;

[0056] 2.3 Configure a dedicated design BOM for a specific model of equipment in this series, and then map and generate a dedicated maintenance BOM based on this design;

[0057] Configuring a dedicated design BOM involves two steps: First, select parts and components from the general design BOM to determine its structure; second, select a specific model number for each component based on the order.

[0058] SEBOM = σ F (GEBOM)

[0059] F: part_id∈P′∧model_id∈MD′ (20)

[0060] In the formula, σ represents the selection operator in relational algebra; F represents the selection condition; P′ represents a set of components required for this type of equipment; MD′ represents a set of models required for this type of equipment;

[0061] A dedicated maintenance BOM will be generated automatically:

[0062] SMBOM = σ F (GMBOM)

[0063] F: part_id∈P′∧model_id∈MD′ (21)

[0064] 2.4 Generate the initial maintenance diagram model for a specific instance of this model of equipment;

[0065] Multiple units of the same model of equipment may be manufactured. The maintenance BOM for a specific unit is as follows:

[0066] SMBOM k =SMBOM (22)

[0067] First, based on the equipment's lifespan and the proactive maintenance plan's cycle, calculate the start and end times for executing the proactive maintenance plan:

[0068] T = {(t_start} i t_end i )|t_start i = t0 + period × i,

[0069]

[0070] In the formula, t_start represents the start time of each maintenance plan; t_end represents the end time of each maintenance plan; t0 represents the time of equipment installation; period represents the execution cycle of the maintenance plan; Δt represents the maximum time to execute one maintenance plan; and life represents the rated service life of the equipment. Then, based on the content of the proactive maintenance plan in the generated maintenance BOM, all TBM activity blocks from equipment installation to scrapping are generated. Finally, all TBM blocks are inserted into the timeline representing the entire lifecycle of the equipment, completing the initial maintenance diagram model of the equipment instance. The mapping function between the maintenance BOM and the initial maintenance diagram model is as follows:

[0071]

[0072] Where Π is the projection operator in relational algebra, × is the Cartesian product in relational algebra, and S is the state domain of the maintenance activity;

[0073] S = {TBM, ICBM, DCBM, BM} (25).

[0074] Step 3: Operation and dynamic updating of equipment maintenance diagram model

[0075] The maintenance activities of the four types of maintenance activity blocks are mapped to three stages under the "event-state" triggering mechanism: the triggering of the start event, the maintenance state, and the triggering of the end event. The maintenance start event is triggered in the detection stage. Once a fault is detected, a maintenance start event is triggered, generating or activating a maintenance activity block, and the equipment enters the maintenance state. The maintenance state includes the identification, decision-making, and planning stages, which require analyzing the cause of the fault, locating the faulty component, and assigning a specific maintenance plan to the worker for execution. Finally, these data are recorded in the maintenance activity block. The maintenance end event is triggered in the execution stage. The worker receives the maintenance task and executes it. After completion, the worker reports the work, triggering the maintenance end event.

[0076] The operation mechanism of the maintenance activities of the four types of maintenance activity blocks is as follows:

[0077] (1) TBM activity operation mechanism

[0078] Triggering the start event: When the current event reaches the scheduled maintenance time, the PMS event is triggered, at which point a scheduled TBM activity block is activated;

[0079] TBM Status: Active maintenance can be viewed as a special type of fault; information such as maintenance methods, tools, fault phenomena and causes, maintained parts, and maintenance personnel during the maintenance process will be recorded in the TBM activity block;

[0080] The termination event is triggered in two ways: Scenario 1: The worker performs maintenance and reports the work before the deadline, triggering the ME event; Scenario 2: The worker does not perform maintenance before the deadline, triggering the O event.

[0081] (2) ICBM activity operation mechanism

[0082] Triggering the start event: When an inspector discovers a fault during an inspection, an IDF event is triggered, at which point an ICBM activity block is generated;

[0083] ICBM Status: The inspector submits a fault description; based on the fault description, the cause of the fault is analyzed, the faulty component is located, a repair plan is developed, and maintenance personnel are arranged to carry out maintenance; all of the above information will be recorded in the ICBM activity block;

[0084] End event triggering: When a worker records the actual maintenance methods and tools used during maintenance and reports the work, the ME event is triggered; after the end event is triggered, an ICBM activity block will be inserted into the maintenance diagram model;

[0085] (3) DCBM activity operation mechanism

[0086] Triggering of the start event: The digital monitoring system detects a fault, triggers a DDF event, and generates a DCBM activity block;

[0087] DCBM Status: Based on the monitored signals, analyze the cause of the fault, locate the faulty component, formulate a repair plan, and arrange maintenance personnel to carry out maintenance; all of the above information will be recorded in the DCBM activity block;

[0088] End event triggering: When a worker records the actual maintenance methods and tools used during maintenance and reports the work, the ME event is triggered; after the end event is triggered, a DCBM activity block will be inserted into the maintenance diagram model;

[0089] (4) BM activity operation mechanism

[0090] Triggering the start event: A sudden failure during operation triggers event A, which generates a BM activity block;

[0091] BM Status: The operator submits a fault description; based on the fault description, the cause of the fault is analyzed, the faulty component is located, a repair plan is developed, and maintenance personnel are arranged to carry out maintenance; all of the above information will be recorded in the BM activity block;

[0092] End event triggering: When a worker records the actual maintenance methods and tools and reports the work during the maintenance process, the ME event is triggered; after the end event is triggered, a BM activity block will be inserted into the maintenance diagram model.

[0093] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0094] Step 1 addresses the formalization of equipment maintenance activities by employing a graphical model construction method based on an "event-state" triggering mechanism. This method establishes a formal graphical model of equipment maintenance activities, which not only supports intuitive visualization of equipment maintenance activities for humans but also allows for deployment on computers for reading, writing, and dynamic updating of these activities.

[0095] 2. Step two addresses the configuration of predefined maintenance activities for equipment by using a BOM-based graphical model initialization configuration method, which can help equipment manufacturers better organize proactive equipment maintenance plans.

[0096] 3. Step three addresses the issue of equipment maintenance activity management by proposing a mechanism for the operation and dynamic updating of maintenance activities. This mechanism can help equipment users achieve computer-aided maintenance of equipment, make it easier to manage and track equipment maintenance activities, reduce the frequency of equipment failures, lower production costs, and increase corporate profits.

[0097] In summary, the device lifecycle maintenance activity diagram model proposed in this invention, based on an "event-state" triggering mechanism, provides device users with a method for managing device maintenance activities using computer assistance. This model not only supports intuitive visualization of device maintenance activities for humans but also supports deployment on a computer for reading, writing, and dynamic updating of these activities. Therefore, it can help device users achieve computer-aided maintenance, more conveniently manage and track device maintenance activities, reduce the frequency of device failures, lower production costs, and increase enterprise profits. Attached Figure Description

[0098] Figure 1 This is the meta-model of the equipment maintenance diagram model proposed in this invention.

[0099] Figure 2 This invention describes the process of constructing the general design BOM and general maintenance BOM for equipment.

[0100] Figure 3 This invention describes the process of configuring a dedicated maintenance BOM for a specific model of equipment.

[0101] Figure 4 This invention describes the process of generating an initialization device maintenance diagram model.

[0102] Figure 5 This invention relates to the operational mechanism of equipment maintenance activities and equipment maintenance diagram model.

[0103] Figure 6 This invention proposes a mechanism for associating the graphical model with the maintenance of BOM instances.

[0104] Figure 7 This invention presents an optimization process for proactive maintenance planning based on a feedback historical maintenance diagram model. Detailed Implementation

[0105] The present invention will now be described in detail with reference to the accompanying drawings, which are an integral part of this application and are used to further explain the invention, but do not constitute a limitation thereof. The graphical model proposed in this invention will be explained in detail from the following three aspects: the construction of the graphical model metamodel based on the "event-state" triggering mechanism, the graphical model initialization configuration for specific device models, and the graphical model's operation and dynamic update mechanism.

[0106] Step 1: Construction of the graph model metamodel based on the "event-state" triggering mechanism

[0107] like Figure 1 As shown, this invention divides equipment maintenance activities into four types of maintenance activity blocks. First, some relevant definitions and concepts are explained.

[0108] State: Defined as a condition in which a device remains stable for a period of time; the state is denoted by S. i This indicates that i represents the state number, and the state transition is triggered by an event;

[0109] An event is defined as a set of operations or actions that occur at a specific point in time and cause a change in the state of a device; events are represented by E. i This indicates that 'i' represents the event number. All events here are instantaneous and have no duration.

[0110] Maintenance activities are defined as all actions aimed at restoring equipment to a state where it can perform its required functions. Maintenance activities consist of five phases: detection, identification, decision-making, planning, and execution.

[0111] The detection phase involves determining whether the equipment has malfunctioned based on its operating conditions and recording the malfunction phenomenon.

[0112] The identification stage involves identifying the cause of the fault and locating the faulty component based on the fault symptoms.

[0113] The decision-making stage involves providing a detailed maintenance plan, as well as the tools and spare parts required during the maintenance process.

[0114] The planning phase involves assigning maintenance tasks to workers and specifying maintenance times.

[0115] The execution phase: Workers perform maintenance tasks according to the maintenance plan and report maintenance details.

[0116] Based on the above definitions and engineering practice research, this invention proposes four basic states and six basic events for equipment maintenance activities.

[0117] The four basic states are: Scheduled Maintenance (TBM) – This refers to the state where workers perform regular, proactive maintenance on equipment according to a proactive maintenance plan. Inspection-Driven In-Situ Maintenance (ICBM) – This refers to the state where inspectors discover equipment faults during inspections and perform maintenance accordingly. Data-Driven In-Situ Maintenance (DCBM) – This refers to the state where maintenance is performed on faults detected by a digital monitoring system. Post-Fault Maintenance (BM) – This refers to the state where workers repair equipment after an accident has occurred.

[0118] Six basic events: Periodic Maintenance Start (PMS) event refers to the event where the planned time for proactive equipment maintenance has arrived. Inspection Detect Fault (IDF) event refers to the event where equipment malfunctions are discovered by inspection personnel during routine inspections. Data Detect Fault (DDF) event refers to the event where equipment malfunctions are discovered through digital monitoring. Accident (A) event refers to an event where equipment experiences a sudden downtime. Overdue (O) event refers to the event where the proactive maintenance plan is not completed on time. Maintenance End (ME) event refers to the event where equipment maintenance is completed.

[0119] S i ∈{TBM, ICBM, DCBM, BM} (1)

[0120] E i ∈{PMS,IDF,DDF,A,O,ME} (2)

[0121] To describe maintenance activities based on the four basic states mentioned above, this invention proposes a formalized model, namely Maintenance Activity Blocks (MABs), which are described using graphics of different colors and shapes. The activity blocks are represented as follows:

[0122] MAB::={TBM, ICBM, DCBM, BM}

[0123]

[0124] MAB describes the equipment maintenance activities, where S... i Represents the state of the activity; Start Event E start and the end event E end These represent the start and end of the maintenance activity, respectively; t start and t end They are E start and E end The time of occurrence, i.e., the start and end times of the maintenance activity; the component requiring maintenance is denoted as P; the worker performing the maintenance is denoted as W; F info This represents the fault information for the maintenance activity; M info This indicates specific maintenance information, defined in detail below:

[0125]

[0126] In the formula, phenomenon is the fault symptom recorded during the detection phase; reason is the fault cause discovered during the identification phase; tool is the required spare parts and tools; and method represents the maintenance method. Tool and method are defined in F... info The middle represents the recommended solution for the decision-making stage, while the middle represents the solution recommended for the decision-making stage. info The middle part represents the actual solution used.

[0127] Since TBM activity blocks are planned before execution, TBM modes are divided into three types: planned, executed, and overdue; planned represents the end event of a TBM activity block. The end event E of the TBM activity block when it has been executed end =ME; The end event E of the TBM activity block after it has expired. end =0 indicates that the equipment has exceeded the planned maintenance period.

[0128] To help equipment manufacturers customize proactive maintenance plans and repair methods for equipment before installation, thereby reminding equipment maintenance personnel to maintain the equipment on time and perform maintenance tasks correctly, this invention describes maintenance activities throughout the entire life cycle of equipment from a macro perspective and proposes a model that can track and manage maintenance activities from equipment installation to scrapping, namely, the equipment maintenance diagram model.

[0129] The equipment maintenance diagram model describes all maintenance activities throughout the entire process of equipment from installation to decommissioning. It is represented as a timeline with maintenance activity blocks inserted, as shown below:

[0130] MGM::={MAB1, MAB2,…,MAB n} (5)

[0131] Using relational algebra theory, it can be expressed as:

[0132] MGM(id, S, E_start, E_end, t_start, t_end, part_id, w_id,

[0133] phenomenon, reason, tool_f, method_f, tool_m, method_m) (6)

[0134] MAB considers it to be a tuple of MGM, that is:

[0135] MAB i ∈MGM

[0136] MAB i = <id i S i E_starti E_end i t_start i t_end i part_id i w_id i (7) phenomenon i reason i tool_f i method_f i ,tool_m i method_m i >

[0137] Step 2: Initialize and configure the schematic model of the specific device based on the BOM.

[0138] Currently, while equipment manufacturers provide manuals outlining maintenance procedures, including information on components requiring maintenance, maintenance schedules, methods, and spare parts, this invention proposes a BOM-based graphical model initialization configuration method to further enhance enterprise digitalization and enable computer-aided maintenance. This method helps equipment manufacturers better organize proactive equipment maintenance plans.

[0139] A Bill of Materials (BOM) is used to describe the component structure of equipment, making it ideal for organizing equipment maintenance. Generating an initial maintenance diagram model of a piece of equipment using BOM theory involves the following four steps:

[0140] 2.1 Construct a general design BOM describing a series of similar devices;

[0141] like Figure 2 As shown, the generic design BOM contains all the components of this product series. According to graph theory, the generic design BOM can be represented as a tree, i.e.:

[0142] GEBOM = (P, A)

[0143] P = {e, p1, p2, ..., p} n}

[0144] A = {a1, a2, ..., a} m} (8)

[0145] In the formula, P represents parts and components; A represents the assembly relationship of parts; e represents equipment, i.e., the root node of the general design BOM tree; p i This represents a part or component; if it has no child nodes, it is a part; otherwise, it is a component. i This indicates assembly relationships. Specific components can be represented as follows:

[0146] pi ={id i name i type i MD i} (9)

[0147] In the formula, id i Indicates the part or component number; name i Indicates name; type i Indicate whether it is a purchased part, a self-made part, or a standard part; MD i Different models of parts are indicated as follows:

[0148] MD i ={model1,model2,…,model n} (10)

[0149] model i ={id i name i code i detail i} (11)

[0150] In the formula, id i The model number; name i Indicates the model name; code i Model code representing the model; detail i Other information about the model.

[0151] Assembly relationships can also be represented as node pairs, i.e.:

[0152] a j = <p k p l > (12)

[0153] 2.2 Summarize the contents of the proactive maintenance plan and add them to the general design BOM to build a general maintenance BOM for a series of similar equipment;

[0154] like Figure 2 As shown, the design BOM emphasizes the structure and component composition of the equipment, while the maintenance BOM adds maintenance information to the design BOM. Therefore, a general maintenance BOM can be represented as follows:

[0155] GMBOM = (P, A)

[0156] P = {e, p1, p1, ..., p} n}

[0157] A = {a1, a1, ..., a1}m} (13)

[0158] A component may have multiple active maintenance items. PM is used to represent the active maintenance items of a part or component:

[0159] PM i ={pm1, pm2, ..., pm n}

[0160] pm i ={name i tool i method i period i} (14)

[0161] In the formula, pm i This represents each specific item of proactive maintenance; name i Indicates the name of the content to be actively maintained; tool i Indicates the maintenance tool used; method i Indicates the maintenance method; period i This indicates the maintenance cycle.

[0162] Associate proactive maintenance content with a specific model of component:

[0163] model i ={id i name i code i detail i PM i} (15)

[0164] To facilitate computer programming, the general design BOM uses relational algebra representation:

[0165] GEBOM(part_id, parent_id, name, typemodel_id, model_name, model_code, model_detail) (16)

[0166] Active maintenance projects can be represented as:

[0167] PM(model_id, pm_id, pm_name, pm_tool, pm_method, pm_period) (17) Therefore, the general maintenance BOM can be represented as:

[0168]

[0169] in, This is the natural join symbol in relational algebra.

[0170] 2.3 Configure a dedicated design BOM for a specific model of equipment in this series, and then map and generate a dedicated maintenance BOM based on this design;

[0171] like Figure 3 As shown, a dedicated design BOM describes the components of a given equipment model. Equipment manufacturers only need to configure the specific design BOM according to the customer's order, and a dedicated maintenance BOM for that equipment model will be automatically generated. The equipment manufacturer first needs to configure the dedicated design BOM, which can be represented as a subtree of the general design BOM, i.e.:

[0172]

[0173] Configuring a dedicated design BOM involves two steps. The first step is to select parts and components from the general design BOM, determining its structure. The second step is to select a specific model number for each component based on the order details.

[0174] SEBOM = σ F (GEBOM)

[0175] F: part_id∈P′∧model_id∈MD′ (20)

[0176] In the formula, σ represents the selection operator in relational algebra; F represents the selection condition; P′ represents a set of components required for this type of equipment; and MD′ represents a set of models required for this type of equipment.

[0177] A dedicated maintenance BOM will be generated automatically:

[0178] SMBOM = σ F (GMBOM)

[0179] F: part_id∈P′∧model_id∈MD′ (21)

[0180] 2.4 Generate the initial maintenance diagram model for a specific instance of this model of equipment.

[0181] Multiple units of the same model of equipment may be manufactured. The maintenance BOM for a specific unit is as follows:

[0182] SMBOM k =SMBOM (22)

[0183] like Figure 4As shown, to configure an initial maintenance diagram model for a specific piece of equipment, it is first necessary to calculate the start and end times of the proactive maintenance plan based on the equipment's lifespan and the cycle of the proactive maintenance plan.

[0184] T = {(t_start} i t_end i )|t_start i = t0 + period × i,

[0185]

[0186] In the formula, t_start represents the start time of each maintenance plan; t_end represents the end time of each maintenance plan; t0 represents the time of equipment installation; period represents the execution cycle of the maintenance plan; Δt represents the maximum time to execute one maintenance plan; and life represents the rated service life of the equipment. Then, based on the content of the proactive maintenance plan in the generated maintenance BOM, all TBM activity blocks from equipment installation to scrapping are generated. Finally, all TBM blocks are inserted into the timeline representing the entire lifecycle of the equipment, completing the initial maintenance diagram model of the equipment instance. The mapping function between the maintenance BOM and the initial maintenance diagram model is as follows:

[0187] Where Π is the projection operator in relational algebra, × is the Cartesian product in relational algebra, and S is the state domain of the maintenance activity.

[0188] S={TBM, ICBM, DCBM, BM} (25)

[0189] Step 3: Operation and dynamic updating of equipment maintenance diagram model

[0190] During the production and operation of equipment, many faults will occur, and corresponding maintenance activities will be carried out. Based on the four maintenance activity blocks proposed above, this invention proposes a set of operation and dynamic update mechanisms for maintenance activities, which are used to illustrate how to represent these faults on the time axis of a graphical model.

[0191] The maintenance activities of the four types of maintenance activity blocks are mapped to three stages under the "event-state" triggering mechanism: the triggering of the start event, the maintenance state, and the triggering of the end event. The maintenance start event is triggered in the detection stage. Once a fault is detected, a maintenance start event is triggered, generating or activating a maintenance activity block, and the equipment enters the maintenance state. The maintenance state includes the identification, decision-making, and planning stages, which require analyzing the cause of the fault, locating the faulty component, and assigning specific maintenance plans to workers for execution. Finally, this data is recorded in the maintenance activity block. The maintenance end event is triggered in the execution stage. Workers receive and execute the maintenance task, and report the completion of the task, triggering the maintenance end event.

[0192] like Figure 5 As shown, the operation mechanism of maintenance activities for the four types of maintenance activity blocks is described in detail.

[0193] (1) TBM activity operation mechanism

[0194] Triggering the start event: When the current event reaches the scheduled maintenance time, the PMS event is triggered, at which point a scheduled TBM activity block is activated.

[0195] TBM Status: Active maintenance can be considered a special type of fault. Information such as maintenance methods, tools, fault symptoms and causes, maintained components, and maintenance personnel will be recorded in the TBM activity block.

[0196] The termination event is triggered in two ways: First, the worker performs maintenance and reports the work before the deadline, triggering the ME event; second, the worker does not perform maintenance before the deadline, triggering the O event.

[0197] (2) ICBM activity operation mechanism

[0198] Triggering the start event: When an inspector discovers a fault during an inspection, an IDF event is triggered, at which point an ICBM activity block is generated.

[0199] ICBM Status: The inspector submits a fault description. Based on the description, the inspector analyzes the cause of the fault, locates the faulty component, develops a repair plan, and arranges for maintenance personnel to perform the repairs. All of this information will be recorded in the ICBM activity block.

[0200] End event triggering: When a worker records the actual maintenance methods and tools used during maintenance and reports the work, the ME event is triggered. After the end event is triggered, an ICBM activity block will be inserted into the maintenance diagram model.

[0201] (3) DCBM activity operation mechanism

[0202] Triggering of the start event: The digital monitoring system detects a fault and triggers a DDF event, which generates a DCBM activity block.

[0203] DCBM Status: Based on the monitored signals, analyze the cause of the fault, locate the faulty component, formulate a repair plan, and arrange maintenance personnel to carry out maintenance. All of the above information will be recorded in the DCBM activity block.

[0204] End event triggering: When a worker records the actual maintenance methods and tools used during maintenance and reports the work, the ME event is triggered. After the end event is triggered, a DCBM activity block will be inserted into the maintenance diagram model.

[0205] (4) BM activity operation mechanism

[0206] Triggering the start event: A sudden failure during operation triggers event A, which generates a BM activity block.

[0207] BM Status: The operator submits a fault description. Based on the description, the cause of the fault is analyzed, the faulty component is located, a repair plan is developed, and maintenance personnel are assigned to perform the repair. All of this information will be recorded in the BM activity block.

[0208] End event triggering: When a worker records the actual maintenance methods and tools used during maintenance and reports the work, the ME event is triggered. After the end event is triggered, a BM activity block will be inserted into the maintenance diagram model.

[0209] In summary, this invention first establishes a meta-model of the maintenance diagram model. Based on a literature review and engineering practice, four maintenance activity strategies are summarized: Time-Based Maintenance (TBM), Inspection-Driven Condition-Based Maintenance (ICBM), Data-Driven Condition-Based Maintenance (DCBM), and Breakdown Maintenance (BM). To describe equipment maintenance activities under different strategies, a maintenance activity diagram model unit based on an "event-state" triggering mechanism, namely the Maintenance Activity Block (MAB), is proposed. Based on this, the four maintenance activity blocks are dynamically inserted into a timeline representing the entire equipment lifecycle according to the order in which maintenance activities occur, to formally describe the dynamic evolution of maintenance activities throughout the equipment's lifecycle.

[0210] Then, combining BOM theory, initial configuration is performed for specific devices based on the graphical meta-model. First, a general design BOM and a general maintenance BOM are built for a series of devices. On this basis, a dedicated design BOM is configured for specific models of devices, and a dedicated maintenance BOM is automatically generated. Finally, the graphical model instance is initialized and configured according to the mapping relationship between the maintenance BOM and the device graphical model.

[0211] Finally, a graphical model-based operational and dynamic update mechanism is used to manage and control maintenance activities throughout the entire equipment lifecycle. Numerous maintenance activities occur during equipment operation. These activities are formally described using maintenance activity blocks, and their maintenance information is recorded. These maintenance activity blocks are dynamically inserted into a timeline representing the entire equipment lifecycle, according to the order in which they occur, thereby describing the maintenance activities throughout the equipment lifecycle and enabling the management and tracking of equipment maintenance activities.

[0212] like Figure 6 As shown, the equipment maintenance diagram model will be associated with the maintenance BOM of this equipment to organize the equipment's maintenance records:

[0213]

[0214] Once the equipment reaches the end of its service life, its maintenance diagram model will be fed back to the equipment manufacturer. Based on this feedback, the manufacturer can continuously optimize the proactive maintenance plan for this series of equipment, such as... Figure 7 As shown.

Claims

1. A method for constructing a graphical model of equipment lifecycle maintenance activities, characterized in that, Includes the following steps: Step 1: Construction of the graph model metamodel based on the "event-state" triggering mechanism Equipment maintenance activities are divided into four types of maintenance activity blocks, described using different colors and shapes. These activity blocks are represented as follows: （3） MAB describes the maintenance activities of the equipment, where... Represents the status of an activity; the start event. and End Event These indicate the start and end of the maintenance activity, respectively. and They are and The time of occurrence, i.e., the start and end times of the maintenance activity; the parts requiring maintenance are denoted as... The workers performing maintenance are referred to as ; This represents fault information related to the maintenance activity; This indicates specific maintenance information, defined in detail below: （4） In the formula These are fault phenomena recorded during the testing phase; This is the cause of the fault discovered during the identification phase; These are the necessary spare parts and tools; The method of maintenance; and exist The middle part indicates the recommended solution to be used during the decision-making stage, while... The middle part represents the actual solution used; Since TBM activity blocks are planned before execution, TBM modes are divided into three types: planned, executed, and overdue; planned is the end event of a TBM activity block. The end event of the TBM activity block when it has been executed. ; The end event of the TBM activity block after the expiration date This indicates that the equipment has exceeded its planned maintenance period; The equipment maintenance diagram model describes all maintenance activities throughout the entire process of equipment from installation to decommissioning. It is represented as a timeline with maintenance activity blocks inserted, as shown below: （5） Using relational algebra theory, it can be expressed as: （6） MAB considers it to be a tuple of MGM, that is: （7）； Step 2. Initialization and configuration of the schematic model of a specific device based on the BOM. The initial maintenance diagram model of a device is generated using BOM theory, including the following four steps: 2.1 Construct a general design BOM describing a series of similar devices; 2.2 Summarize the contents of the proactive maintenance plan and add them to the general design BOM to build a general maintenance BOM for a series of similar equipment; 2.3 Configure a dedicated design BOM for a specific model of equipment in this series, and then map and generate a dedicated maintenance BOM based on this design; Configuring a dedicated design BOM involves two steps: First, select parts and components from the general design BOM to determine its structure; second, select a specific model number for each component based on the order. （20） In the formula, Represents the selection operator in relational algebra; Indicates selection criteria; This refers to a set of components required for this type of equipment; A set of models is required to represent this type of device; A dedicated maintenance BOM will be generated automatically: （21） 2.4 Generate the initial maintenance diagram model for a specific instance of this model of equipment; Multiple units of the same model of equipment may be manufactured. The maintenance BOM for a specific unit is as follows: （22） First, based on the equipment's lifespan and the proactive maintenance plan's cycle, calculate the start and end times for executing the proactive maintenance plan: （23） In the formula, Indicates the start time of each maintenance plan; Indicates the deadline for each maintenance plan; Indicates the time when the equipment was installed; Indicates the execution cycle of the maintenance plan; Indicates the maximum time required to execute a single maintenance plan; The rated service life of the equipment is indicated. Then, based on the content of the proactive maintenance plan in the generated maintenance BOM, all TBM activity blocks from the installation to the scrapping of the equipment are generated. Finally, all TBM blocks are inserted into the timeline representing the entire life cycle of the equipment to complete the initial maintenance diagram model of the equipment instance. Step 3. Operation and Dynamic Update of Equipment Maintenance Diagram Model The maintenance activities of the four types of maintenance activity blocks are mapped to three stages under the "event-state" triggering mechanism: the triggering of the start event, the maintenance state, and the triggering of the end event. The maintenance start event is triggered in the detection stage. Once a fault is detected, a maintenance start event will be triggered, generating or activating a maintenance activity block, and the device will enter the maintenance state. The maintenance process includes identification, decision-making, and planning phases. It requires analyzing the cause of the failure, locating the faulty component, and assigning specific maintenance plans to workers for execution. Finally, these data are recorded in the maintenance activity block. The maintenance completion event is triggered during the execution phase. Workers receive maintenance tasks, execute them, and report the completion of the task, triggering the maintenance completion event.

2. The method for constructing a diagrammatic model of equipment lifecycle maintenance activities according to claim 1, characterized in that, Step two involves constructing a generic design BOM describing a series of similar devices; specifically: The generic design BOM contains all the components of this product series. According to graph theory, the generic design BOM can be represented as a tree, i.e.: （8） In the formula, Indicates parts and components; Indicates the assembly relationship of parts; The representative device is the root node of the general design BOM tree; This represents a part or component. If it has no child nodes, it is a part; otherwise, it is a component. This indicates the assembly relationship; specific components are represented as follows: （9） In the formula, Indicates the part or component number; Indicates the name; Indicate whether it is a purchased part, a self-made part, or a standard part; Different models of parts are indicated as follows: （10） （11） In the formula, The model number; Indicates the model name; The model code representing the model; Other information representing the model; Assembly relationships are represented as node pairs, i.e.: （12） The general maintenance BOM in step two is represented as follows: （13） A single component may have multiple active maintenance requirements, and its use... This indicates the active maintenance content for a part or component: （14） In the formula, This represents each specific proactive maintenance item; Indicates the name of the content to be actively maintained; Indicates the maintenance tools used; Indicate the maintenance method; Indicates the maintenance cycle; Associate proactive maintenance content with a specific model of component: （15） To facilitate computer programming, the general design BOM uses relational algebra representation: （16） Actively maintained projects are represented as: （17） Therefore, the general maintenance BOM is represented as: （18） in, The natural join symbol in relational algebra; The mapping function between maintaining the BOM and the initial maintenance diagram model in step two is as follows: （24） in, For projection operators in relational algebra, For Cartesian product in relational algebra, To maintain the state domain of the activity; （25）。 3. The method for constructing a diagrammatic model of equipment lifecycle maintenance activities according to claim 1, characterized in that, The operation mechanism of the maintenance activities of the four maintenance activity blocks mentioned in step three is as follows: (1) TBM activity operation mechanism Triggering the start event: When the current event reaches the scheduled maintenance time, the PMS event is triggered, at which point a scheduled TBM activity block is activated; TBM status: Active maintenance can be viewed as a special type of fault; The maintenance methods, tools, fault phenomena and causes, maintained parts, and maintenance personnel information during the maintenance process will all be recorded in the TBM activity block; The termination event is triggered in two ways: Scenario 1: The worker performs maintenance and reports the work before the deadline, triggering the ME event; Scenario 2: The worker does not perform maintenance before the deadline, triggering the O event. (2) ICBM activity operation mechanism Triggering the start event: When an inspector discovers a fault during an inspection, an IDF event is triggered, at which point an ICBM activity block is generated; ICBM Status: The inspector submits a fault description; based on the fault description, the cause of the fault is analyzed, the faulty component is located, a repair plan is developed, and maintenance personnel are arranged to carry out maintenance; all of the above information will be recorded in the ICBM activity block; End event triggering: When a worker records the actual maintenance methods and tools used during maintenance and reports the work, the ME event is triggered; after the end event is triggered, an ICBM activity block will be inserted into the maintenance diagram model; (3) DCBM activity operation mechanism Triggering of the start event: The digital monitoring system detects a fault, triggers a DDF event, and generates a DCBM activity block; DCBM Status: Based on the monitored signals, analyze the cause of the fault, locate the faulty component, formulate a repair plan, and arrange maintenance personnel to carry out maintenance; all of the above information will be recorded in the DCBM activity block; End event triggering: When a worker records the actual maintenance methods and tools used during maintenance and reports the work, the ME event is triggered; after the end event is triggered, a DCBM activity block will be inserted into the maintenance diagram model; (4) BM activity operation mechanism Triggering the start event: A sudden failure during operation triggers event A, which generates a BM activity block; BM Status: The operator submits a fault description; based on the fault description, the cause of the fault is analyzed, the faulty component is located, a repair plan is developed, and maintenance personnel are arranged to carry out maintenance; all of the above information will be recorded in the BM activity block; End event triggering: When a worker records the actual maintenance methods and tools and reports the work during the maintenance process, the ME event is triggered; after the end event is triggered, a BM activity block will be inserted into the maintenance diagram model.

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