Method, device and equipment for identifying bottlenecks in assembly lines based on industrial Internet

Abstract

The present application provides a method, device and equipment for identifying bottlenecks in an assembly line based on industrial Internet, relating to the field of big data. The method includes: determining the failure rate and repair rate of an equivalent machine composed of each assembly machine and the corresponding line-side inventory based on the probability of the assembly machine being in a working state, the probability of the part replenishment system successfully replenishing parts to the line-side inventory, the maximum capacity of the line-side inventory, the replenishment threshold of the line-side inventory, the number of parts in the line-side inventory, the working state of the part replenishment system, and the maximum capacity of the buffer; determining the blocking rate and starvation rate of the equivalent machine based on the failure rate and repair rate of the equivalent machine and the maximum capacity of the buffer; and determining the bottleneck among multiple equivalent machines of the assembly line according to the blocking rate and starvation rate of the equivalent machine. By comprehensively considering multi-dimensional parameters of the assembly machine, part replenishment system, line-side inventory and buffer, the method can accurately identify the bottleneck in the assembly line.

Description

Technical Field

[0001] This application relates to the field of big data, and in particular, to a method, device, and equipment for identifying bottlenecks in an assembly line based on the industrial Internet. Background Art

[0002] In assembly line production, bottleneck identification can identify specific links in the production process that hinder the improvement of overall efficiency and cost control. By optimizing these bottlenecks, production efficiency can be increased, resource waste can be reduced, and the smooth progress of the production process can be ensured, thereby enhancing the overall production benefit.

[0003] Traditional bottleneck identification methods mainly quantify and evaluate the working efficiency of the assembly line, and identify bottlenecks in the assembly line production process based on direct factors such as the failure rate, downtime, and operation time of the assembly machines.

[0004] However, due to the complex composition of the assembly line, involving multiple intertwined factors and links, traditional bottleneck identification methods cannot accurately identify the real bottlenecks in the assembly line. Summary of the Invention

[0005] This application provides a method, device, and equipment for identifying bottlenecks in an assembly line based on the industrial Internet, so as to solve the technical problem that traditional bottleneck identification methods cannot accurately identify the real bottlenecks in the assembly line.

[0006] In a first aspect, this application provides a method for identifying bottlenecks in an assembly line based on the industrial Internet. The assembly line includes multiple assembly machines that sequentially perform different part assemblies. Each assembly machine has a corresponding in-line inventory for storing the parts corresponding to the assembly machine. The parts in the in-line inventory are replenished by the corresponding part replenishment system. There is a buffer between two assembly machines for storing work-in-progress. The method includes:

[0007] Based on the probability that the assembly machine is in a working state, the probability that the part replenishment system successfully replenishes parts to the in-line inventory, the maximum capacity of the in-line inventory, the replenishment threshold of the in-line inventory, the number of parts in the in-line inventory, the working state of the part replenishment system, and the maximum capacity of the buffer, determine the failure rate and repair rate of the equivalent machine composed of each assembly machine and the corresponding in-line inventory;

[0008] Determine the blocking rate and starvation rate of the equivalent machine based on the failure rate and repair rate of the equivalent machine and the maximum capacity of the buffer, where the blocking rate of the equivalent machine is the probability that the buffer after the equivalent machine reaches the maximum capacity, the equivalent machine is in the working state, and the next equivalent machine of the equivalent machine cannot complete the assembly; the starvation rate of the equivalent machine is the probability that there is no work-in-progress in the buffer before the equivalent machine and the equivalent machine is in the working state;

[0009] Determine the bottleneck among the multiple equivalent machines of the assembly line according to the blocking rate and starvation rate of the equivalent machine.

[0010] In a possible implementation manner, the determining the failure rate and repair rate of the equivalent machine composed of each assembly machine and the corresponding line-side inventory based on the probability that the assembly machine is in the working state, the probability that the part replenishment system successfully replenishes parts to the line-side inventory, the maximum capacity of the line-side inventory, the replenishment threshold of the line-side inventory, the number of parts in the line-side inventory, the working state of the part replenishment system, and the maximum capacity of the buffer includes:

[0011] Determine the initial failure rate and initial repair rate of each equivalent machine based on the probability that the assembly machine is in the working state, the probability that the part replenishment system successfully replenishes parts to the line-side inventory, the maximum capacity of the line-side inventory, the replenishment threshold of the line-side inventory, the number of parts in the line-side inventory, and the working state of the part replenishment system;

[0012] Based on the assembly sequence of all the equivalent machines on the assembly line, the initial failure rate and initial repair rate of each equivalent machine, and the maximum capacity of the buffer, perform at least one round of update on the initial failure rate and initial repair rate of each equivalent machine to obtain the failure rate and repair rate of each equivalent machine.

[0013] In a possible implementation manner, the performing at least one round of update on the initial failure rate and initial repair rate of each equivalent machine based on the assembly sequence of all the equivalent machines on the assembly line, the initial failure rate and initial repair rate of each equivalent machine, and the maximum capacity of the buffer to obtain the failure rate and repair rate of each equivalent machine includes:

[0014] Based on the assembly sequence of all the equivalent machines on the assembly line, initialize the forward aggregated failure rate and forward aggregated repair rate of the first equivalent machine, the backward aggregated failure rate and backward aggregated repair rate of the last equivalent machine, and the forward aggregated failure rate and forward aggregated repair rate of the other equivalent machines except the first and the last in the first round of update;

[0015] In each round of update, in the order from the back to the front, based on the backward aggregated failure rate and backward aggregated repair rate of the first equivalent machine, the forward aggregated failure rate and forward aggregated repair rate of the second equivalent machine, the initial failure rate and initial repair rate of the second equivalent machine, and the maximum capacity of the buffer between the first equivalent machine and the second equivalent machine, determine the updated backward aggregated failure rate and backward aggregated repair rate of the second equivalent machine. And, in the order from the front to the back, based on the forward aggregated failure rate and forward aggregated repair rate of the third equivalent machine, the backward aggregated failure rate and backward aggregated repair rate of the fourth equivalent machine, the initial failure rate and initial repair rate of the fourth equivalent machine, and the maximum capacity of the buffer between the third equivalent machine and the fourth equivalent machine, determine the updated forward aggregated failure rate and forward aggregated repair rate of the fourth equivalent machine. Wherein, the first equivalent machine is the latter one of two adjacent equivalent machines, the second equivalent machine is the previous equivalent machine of the first equivalent machine, the third equivalent machine is the former one of two adjacent equivalent machines, and the fourth equivalent machine is the latter one of the first equivalent machine;

[0016] Judge whether the backward aggregated failure rate, backward aggregated repair rate, forward aggregated failure rate and forward aggregated repair rate of each updated equivalent machine meet the convergence condition. If so, determine the backward aggregated failure rate and forward aggregated failure rate of each updated equivalent machine as the failure rate of each equivalent machine, and determine the backward aggregated repair rate and forward aggregated repair rate of each updated equivalent machine as the repair rate of each equivalent machine. If not, continue to perform the next round of update.

[0017] In a possible implementation manner, the determining the blocking rate and starvation rate of the equivalent machine based on the failure rate and repair rate of the equivalent machine and the maximum capacity of the buffer includes:

[0018] According to the initial failure rate and initial repair rate of the fifth equivalent machine, the forward aggregated failure rate and forward aggregated repair rate of the fifth equivalent machine, the backward aggregated failure rate and backward aggregated repair rate of the sixth equivalent machine, and the maximum capacity of the buffer between the fifth equivalent machine and the sixth equivalent machine, determine the blocking rate of the fifth equivalent machine, where the fifth equivalent machine is any equivalent machine except the last equivalent machine, and the sixth equivalent machine is the next equivalent machine of the fifth equivalent machine;

[0019] Determine the starvation rate of the seventh equivalent machine according to the initial failure rate and initial repair rate of the seventh equivalent machine, the backward aggregation failure rate and backward aggregation repair rate of the seventh equivalent machine, the forward aggregation failure rate and forward aggregation repair rate of the eighth equivalent machine, and the maximum capacity of the buffer between the seventh equivalent machine and the eighth equivalent machine, where the seventh equivalent machine is any equivalent machine other than the first equivalent machine, and the eighth equivalent machine is the equivalent machine preceding the seventh equivalent machine.

[0020] In a possible implementation, the determining the bottleneck among the multiple equivalent machines of the assembly line according to the blockage rate and starvation rate of the equivalent machines includes:

[0021] For any equivalent machine other than the last equivalent machine, determine the first change rate of the productivity of the assembly line with respect to the influencing factor according to the initial failure rate and initial repair rate of the equivalent machine, the starvation rate of the next equivalent machine of the equivalent machine, the probability that the assembly machine in the equivalent machine is in the working state, the probability that the parts replenishment system successfully replenishes parts for the line-side inventory in the equivalent machine, the maximum capacity of the line-side inventory in the equivalent machine, and the replenishment threshold of the line-side inventory in the equivalent machine, where the influencing factor is any one of the following: the probability that the assembly machine is in the working state, the probability that the parts replenishment system successfully replenishes parts for the line-side inventory, the replenishment threshold of the line-side inventory, and the maximum capacity of the line-side inventory;

[0022] For any equivalent machine other than the first equivalent machine, determine the second change rate of the productivity of the assembly line with respect to the influencing factor according to the initial failure rate and initial repair rate of the equivalent machine, the blockage rate of the previous equivalent machine of the equivalent machine, the probability that the assembly machine in the equivalent machine is in the working state, the probability that the parts replenishment system successfully replenishes parts for the line-side inventory in the equivalent machine, the maximum capacity of the line-side inventory in the equivalent machine, and the replenishment threshold of the line-side inventory in the equivalent machine;

[0023] Determine the bottleneck among the multiple equivalent machines of the assembly line according to the first change rate and the second change rate.

[0024] In a possible implementation, the determining the bottleneck among the multiple equivalent machines of the assembly line according to the first change rate and the second change rate includes:

[0025] For the first equivalent machine, if the first change rate corresponding to the first equivalent machine is greater than the second change rate corresponding to the second equivalent machine, then the first equivalent machine is the bottleneck;

[0026] For any equivalent machine except the first equivalent machine and the last equivalent machine, if the first change rate corresponding to the any equivalent machine is greater than the second change rate corresponding to the next equivalent machine of the any equivalent machine, and the second change rate corresponding to the any equivalent machine is greater than the first change rate corresponding to the previous equivalent machine of the any equivalent machine, then the any equivalent machine is a bottleneck;

[0027] For the last equivalent machine, if the second change rate corresponding to the last equivalent machine is greater than the first change rate corresponding to the penultimate equivalent machine, then the last equivalent machine is a bottleneck.

[0028] In a possible implementation manner, it further includes:

[0029] When there are multiple bottlenecks in the assembly line, determine the bottleneck severity score corresponding to each bottleneck according to the first change rate and the second change rate, and determine the bottleneck with the largest bottleneck severity score as the core bottleneck of the assembly line.

[0030] In a possible implementation manner, the determining the bottleneck severity score corresponding to each bottleneck according to the first change rate and the second change rate includes:

[0031] When the first equivalent machine is a bottleneck, determine the absolute value of the difference between the first change rate corresponding to the first equivalent machine and the second change rate corresponding to the second equivalent machine as the bottleneck severity score corresponding to the first equivalent machine;

[0032] When any equivalent machine except the first equivalent machine and the last equivalent machine is a bottleneck, determine the absolute value of the sum of the difference between the first change rate corresponding to the any equivalent machine and the second change rate corresponding to the next equivalent machine of the any equivalent machine, and the absolute value of the difference between the second change rate corresponding to the any equivalent machine and the first change rate corresponding to the previous equivalent machine of the any equivalent machine as the bottleneck severity score corresponding to the any equivalent machine;

[0033] When the last equivalent machine is a bottleneck, determine the absolute value of the difference between the second change rate corresponding to the last equivalent machine and the first change rate corresponding to the penultimate equivalent machine as the bottleneck severity score corresponding to the last equivalent machine.

[0034] In a second aspect, the present application provides an assembly line bottleneck identification device based on an industrial Internet, including:

[0035] A determination module, configured to determine the failure rate and repair rate of an equivalent machine formed by each of the assembly machines and the corresponding line-side inventory based on the probability that the assembly machine is in a working state, the probability that the part replenishment system successfully replenishes parts to the line-side inventory, the maximum capacity of the line-side inventory, the replenishment threshold of the line-side inventory, the number of parts in the line-side inventory, the working state of the part replenishment system, and the maximum capacity of the buffer;

[0036] The determination module is further configured to determine the blocking rate and starvation rate of the equivalent machine based on the failure rate and repair rate of the equivalent machine and the maximum capacity of the buffer, where the blocking rate of the equivalent machine is the probability that the buffer after the equivalent machine reaches the maximum capacity, the equivalent machine is in a working state, and the next equivalent machine of the equivalent machine cannot complete the assembly; the starvation rate of the equivalent machine is the probability that there is no work-in-progress in the buffer before the equivalent machine and the equivalent machine is in a working state;

[0037] The determination module is further configured to determine the bottleneck among the multiple equivalent machines of the assembly line according to the blocking rate and starvation rate of the equivalent machine.

[0038] In a possible implementation manner, the determination module is further configured to determine the initial failure rate and initial repair rate of each equivalent machine based on the probability that the assembly machine is in a working state, the probability that the part replenishment system successfully replenishes parts to the line-side inventory, the maximum capacity of the line-side inventory, the replenishment threshold of the line-side inventory, the number of parts in the line-side inventory, and the working state of the part replenishment system;

[0039] The determination module is further configured to perform at least one round of update on the initial failure rate and initial repair rate of each equivalent machine based on the assembly sequence of all the equivalent machines on the assembly line, the initial failure rate and initial repair rate of each equivalent machine, and the maximum capacity of the buffer, so as to obtain the failure rate and repair rate of each equivalent machine.

[0040] In a possible implementation manner, the assembly line bottleneck identification device based on the industrial Internet further includes: a processing module and a judgment module;

[0041] The processing module is configured to initialize the forward aggregated failure rate and forward aggregated repair rate of the first equivalent machine, the backward aggregated failure rate and backward aggregated repair rate of the last equivalent machine, and the forward aggregated failure rate and forward aggregated repair rate of other equivalent machines in the first round of update based on the assembly sequence of all the equivalent machines on the assembly line;

[0042] The determining module is further configured to, in each round of update, in the order from the back to the front, based on the backward aggregated failure rate and backward aggregated repair rate of the first equivalent machine, the forward aggregated failure rate and forward aggregated repair rate of the second equivalent machine, the initial failure rate and initial repair rate of the second equivalent machine, and the maximum capacity of the buffer between the first equivalent machine and the second equivalent machine, determine the updated backward aggregated failure rate and backward aggregated repair rate of the second equivalent machine; and in the order from the front to the back, based on the forward aggregated failure rate and forward aggregated repair rate of the third equivalent machine, the backward aggregated failure rate and backward aggregated repair rate of the fourth equivalent machine, the initial failure rate and initial repair rate of the fourth equivalent machine, and the maximum capacity of the buffer between the third equivalent machine and the fourth equivalent machine, determine the updated forward aggregated failure rate and forward aggregated repair rate of the fourth equivalent machine, where the first equivalent machine is the latter one of two adjacent equivalent machines, the second equivalent machine is the previous equivalent machine of the first equivalent machine, the third equivalent machine is the former one of two adjacent equivalent machines, and the fourth equivalent machine is the latter one of the first equivalent machine;

[0043] The judging module is configured to judge whether the backward aggregated failure rate, backward aggregated repair rate, forward aggregated failure rate, and forward aggregated repair rate of each updated equivalent machine meet the convergence condition;

[0044] The determining module is further configured to, if the conditions are met, determine the backward aggregated failure rate and forward aggregated failure rate of each updated equivalent machine as the failure rate of each equivalent machine, and determine the backward aggregated repair rate and forward aggregated repair rate of each updated equivalent machine as the repair rate of each equivalent machine; if the conditions are not met, continue to perform the next round of update.

[0045] In a possible implementation manner, the determining module is further configured to determine the blocking rate of the fifth equivalent machine according to the initial failure rate and initial repair rate of the fifth equivalent machine, the forward aggregated failure rate and forward aggregated repair rate of the fifth equivalent machine, the backward aggregated failure rate and backward aggregated repair rate of the sixth equivalent machine, and the maximum capacity of the buffer between the fifth equivalent machine and the sixth equivalent machine, where the fifth equivalent machine is any equivalent machine except the last equivalent machine, and the sixth equivalent machine is the next equivalent machine of the fifth equivalent machine;

[0046] The determining module is further configured to determine the starvation rate of the seventh equivalent machine according to the initial failure rate and initial repair rate of the seventh equivalent machine, the backward aggregated failure rate and backward aggregated repair rate of the seventh equivalent machine, the forward aggregated failure rate and forward aggregated repair rate of the eighth equivalent machine, and the maximum capacity of the buffer between the seventh equivalent machine and the eighth equivalent machine, where the seventh equivalent machine is any equivalent machine other than the first equivalent machine, and the eighth equivalent machine is the previous equivalent machine of the seventh equivalent machine.

[0047] In a possible implementation manner, the determining module is further configured to, for any equivalent machine other than the last equivalent machine, determine a first change rate of the productivity of the assembly line with respect to an influencing factor according to the initial failure rate and initial repair rate of the equivalent machine, the starvation rate of the next equivalent machine of the equivalent machine, the probability that the assembly machine in the equivalent machine is in a working state, the probability that the parts replenishment system successfully replenishes parts for the line-side inventory in the equivalent machine, the maximum capacity of the line-side inventory in the equivalent machine, and the replenishment threshold of the line-side inventory in the equivalent machine, where the influencing factor is any one of the following: the probability that the assembly machine is in a working state, the probability that the parts replenishment system successfully replenishes parts for the line-side inventory, the replenishment threshold of the line-side inventory, and the maximum capacity of the line-side inventory;

[0048] The determining module is further configured to, for any equivalent machine other than the first equivalent machine, determine a second change rate of the productivity of the assembly line with respect to the influencing factor according to the initial failure rate and initial repair rate of the equivalent machine, the blocking rate of the previous equivalent machine of the equivalent machine, the probability that the assembly machine in the equivalent machine is in a working state, the probability that the parts replenishment system successfully replenishes parts for the line-side inventory in the equivalent machine, the maximum capacity of the line-side inventory in the equivalent machine, and the replenishment threshold of the line-side inventory in the equivalent machine;

[0049] The determining module is further configured to determine the bottleneck among multiple equivalent machines of the assembly line according to the first change rate and the second change rate.

[0050] In a possible implementation manner, for the first equivalent machine, if the first change rate corresponding to the first equivalent machine is greater than the second change rate corresponding to the second equivalent machine, the first equivalent machine is the bottleneck;

[0051] The determining module is further configured to, for any equivalent machine other than the first equivalent machine and the last equivalent machine, if the first change rate corresponding to the any equivalent machine is greater than the second change rate corresponding to the next equivalent machine of the any equivalent machine, and the second change rate corresponding to the any equivalent machine is greater than the first change rate corresponding to the previous equivalent machine of the any equivalent machine, then the any equivalent machine is a bottleneck;

[0052] The determining module is further configured to, for the last equivalent machine, if the second change rate corresponding to the last equivalent machine is greater than the first change rate corresponding to the penultimate equivalent machine, then the last equivalent machine is a bottleneck.

[0053] In a possible implementation manner, the determining module is further configured to, when there are multiple bottlenecks in the assembly line, determine a bottleneck severity score corresponding to each bottleneck according to the first change rate and the second change rate, and determine the bottleneck with the largest bottleneck severity score as the core bottleneck of the assembly line.

[0054] In a possible implementation manner, the determining module is further configured to, when the first equivalent machine is a bottleneck, determine the absolute value of the difference between the first change rate corresponding to the first equivalent machine and the second change rate corresponding to the second equivalent machine as the bottleneck severity score corresponding to the first equivalent machine;

[0055] The determining module is further configured to, when any equivalent machine other than the first equivalent machine and the last equivalent machine is a bottleneck, determine the sum of the absolute value of the difference between the first change rate corresponding to the any equivalent machine and the second change rate corresponding to the next equivalent machine of the any equivalent machine, and the absolute value of the difference between the second change rate corresponding to the any equivalent machine and the first change rate corresponding to the previous equivalent machine of the any equivalent machine as the bottleneck severity score corresponding to the any equivalent machine;

[0056] The determining module is further configured to, when the last equivalent machine is a bottleneck, determine the absolute value of the difference between the second change rate corresponding to the last equivalent machine and the first change rate corresponding to the penultimate equivalent machine as the bottleneck severity score corresponding to the last equivalent machine.

[0057] In a third aspect, an embodiment of the present application provides an assembly line bottleneck identification device based on an industrial Internet, including: a memory, a processor;

[0058] The memory stores computer execution instructions;

[0059] The processor executes the computer-executable instructions stored in the memory, such that the processor performs the above first aspect and / or various possible implementation manners of the first aspect.

[0060] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, in which computer-executable instructions are stored, and when the computer-executable instructions are executed by a processor, they are used to implement the above first aspect and / or various possible implementation manners of the first aspect.

[0061] In a fifth aspect, an embodiment of the present application provides a computer program product, including a computer program, and when the computer program is executed by a processor, it implements the above first aspect and / or various possible implementation manners of the first aspect.

[0062] The method for identifying bottlenecks in an assembly line based on the industrial Internet provided by the present application determines the failure rate and repair rate of an equivalent machine composed of each assembly machine and the corresponding line-side inventory based on the probability that the assembly machine is in a working state, the probability that the part replenishment system successfully replenishes parts to the line-side inventory, the maximum capacity of the line-side inventory, the replenishment threshold of the line-side inventory, the number of parts in the line-side inventory, the working state of the part replenishment system, and the maximum capacity of the buffer. Based on the failure rate and repair rate of the equivalent machine and the maximum capacity of the buffer, the blocking rate and starvation rate of the equivalent machine are determined. The blocking rate of the equivalent machine is the probability that the buffer after the equivalent machine reaches the maximum capacity, the equivalent machine is in a working state, and the next equivalent machine of the equivalent machine cannot complete the assembly; the starvation rate of the equivalent machine is the probability that there is no work-in-process in the buffer before the equivalent machine and the equivalent machine is in a working state. Based on the blocking rate and starvation rate of the equivalent machine, the bottleneck in the multiple equivalent machines of the assembly line is determined. By comprehensively considering multi-dimensional parameters of the assembly machine, the part replenishment system, the line-side inventory, and the buffer, this method calculates the failure rate, repair rate, blocking rate, and starvation rate of the equivalent machine, thereby accurately identifying the bottleneck in the assembly line. Description of the Drawings

[0063] The drawings here are incorporated into the description and constitute a part of this description, showing embodiments consistent with the present application, and are used together with the description to explain the principles of the present application.

[0064] Figure 1 It is a schematic structural diagram of the assembly line provided by the present application;

[0065] Figure 2 It is a schematic flow diagram of the method for identifying bottlenecks in an assembly line based on the industrial Internet provided by the present application;

[0066] Figure 3 It is a schematic structural diagram of the device for identifying bottlenecks in an assembly line based on the industrial Internet provided by the present application;

[0067] Figure 4 The structural schematic diagram of the assembly line bottleneck identification device provided for this application based on the industrial Internet.

[0068] Through the above-mentioned drawings, the specific embodiments of this application have been shown, and there will be more detailed descriptions hereinafter. These drawings and textual descriptions are not intended to limit the scope of the concept of this application in any way, but to illustrate the concept of this application to those skilled in the art by referring to specific embodiments. Specific Embodiments

[0069] Here, the exemplary embodiments will be described in detail, and the examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. On the contrary, they are merely examples of devices and methods consistent with some aspects of this application.

[0070] In assembly line production, bottleneck identification can deeply analyze the production process and locate the specific machines that hinder the improvement of overall efficiency and cost control. By optimizing these bottleneck machines, the production efficiency of the assembly line can be improved, and resource waste can be significantly reduced, thus ensuring the smoothness of the production process.

[0071] Traditional bottleneck identification methods rely on the quantitative evaluation of the working efficiency of the assembly line, and determine the bottlenecks in the production process through intuitive factors such as the failure rate, downtime, and operation time of the assembly machines.

[0072] However, due to the rather complex composition of the assembly line, involving multiple intertwined factors and links, traditional bottleneck identification methods are difficult to accurately identify the real bottlenecks in the assembly line.

[0073] To address the above problems, the assembly line bottleneck identification method provided for this application constructs an assembly line bottleneck identification system based on the industrial Internet by combining multi-dimensional information such as the operating status of the assembly machines, the effectiveness of the part replenishment system, the management parameters of the line-side inventory, and the capacity limit of the buffer. According to the parameters of the assembly machines and the corresponding line-side inventory, calculate the failure rate and repair rate of each equivalent machine; combined with the maximum capacity of the buffer, analyze and obtain the blocking rate (i.e., the stagnation probability caused by the subsequent buffer being full and the subsequent equivalent machine being unable to operate) and starvation rate (i.e., the probability that the equivalent machine is idle due to the lack of in-process products in the pre-buffer) of the equivalent machine during operation, and determine the bottleneck of the assembly line; this method can accurately identify the potential bottlenecks in each equivalent machine on the assembly line.

[0074] The technical solution of the present application and how the technical solution of the present application solves the above technical problems will be described in detail below with specific embodiments. The following several specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0075] Figure 1 is a schematic structural diagram of the assembly line provided by the present application. As Figure 1 shown, the schematic structural diagram of the specific assembly line of the present application includes:

[0076] The assembly line includes multiple assembly machines that sequentially perform different part assemblies , and each assembly machine has a corresponding in-line inventory . The in-line inventory is used to store the parts corresponding to the assembly machine, and the parts in the in-line inventory are replenished by the corresponding part replenishment system. There is a buffer between two assembly machines , and the buffer is used to store work-in-progress.

[0077] represents the th assembly machine. The assembly machines have the same and fixed operation cycles.

[0078] represents the in-line inventory corresponding to the th assembly machine. The part replenishment system adopts an inventory control strategy to replenish parts for the in-line inventory . Among them, , . The number of parts in the in-line inventory , among which, .

[0079] represents the buffer between assembly machine and assembly machine . The maximum value of the number of work-in-progress in the buffer .

[0080] The working process of the assembly line is as follows: taking the to-be-assembled part as the input, first, assembly machine selects parts from the in-line inventory and assembles them onto the to-be-assembled part. After the initial assembly is completed, it is transferred to the buffer ; then, the to-be-assembled part in the buffer is conveyed to the next assembly machine , and assembly machine selects parts from the in-line inventory Parts are selected from it for assembly, and after the assembly operation is completed, they are transferred to the buffer area ; This process loops continuously until reaching the assembly machine The assembly machine selects parts from the line-side inventory for assembly and transfers them to the buffer area ; Finally, the parts to be assembled in the buffer area are conveyed to the assembly machine The assembly machine selects parts from the line-side inventory to complete the final assembly, and the output is the finished product.

[0081] Figure 2 is the process schematic diagram of the assembly line bottleneck identification method provided by this application. The execution subject of this embodiment is, for example, an assembly line bottleneck identification system. As Figure 2 shown, the assembly line bottleneck identification method based on the industrial Internet shown in this embodiment includes:

[0082] S101: Based on the probability that the assembly machine is in the working state, the probability that the part replenishment system successfully replenishes parts to the line-side inventory, the maximum capacity of the line-side inventory, the replenishment threshold of the line-side inventory, the number of parts in the line-side inventory, the working state of the part replenishment system, and the maximum capacity of the buffer area, determine the failure rate and repair rate of the equivalent machine composed of each assembly machine and the corresponding line-side inventory.

[0083] Among them, the state of the assembly machine obeys the Bernoulli reliability model. In each time period, the assembly machine is in the working state with a probability of and in the failure state with a probability of .

[0084] The result of the part replenishment system replenishing parts to the line-side inventory follows a Bernoulli distribution with a parameter of , that is, at each moment, the probability of successfully replenishing one part to the line-side inventory is . To ensure the normal operation of the assembly line, it is assumed that the efficiency of the part replenishment system is greater than the efficiency of the assembly machine, that is .

[0085] The maximum capacity of the line-side inventory is , the replenishment threshold of the line-side inventory is , the number of parts in the line-side inventory is , and the maximum capacity of the buffer area is .

[0086] The equivalent machine is the assembly machine and the line-side inventory constitute an independent machine, representing the th equivalent machine.

[0087] The failure rate of the equivalent machine represents the failure rate of the th equivalent machine. The failure rate of the equivalent machine is used to indicate the probability that the th equivalent machine transitions from the working state to the failed state.

[0088] The repair rate of the equivalent machine represents the repair rate of the th equivalent machine. The repair rate of the equivalent machine is used to indicate the probability that the th equivalent machine transitions from the failed state to the working state.

[0089] S102: Based on the failure rate and repair rate of the equivalent machine, and the maximum capacity of the buffer, determine the blocking rate and starvation rate of the equivalent machine. Among them, the blocking rate of the equivalent machine is the probability that the buffer after the equivalent machine reaches the maximum capacity, the equivalent machine is in the working state, and the next equivalent machine of the equivalent machine cannot complete the assembly; the starvation rate of the equivalent machine is the probability that there is no work-in-process in the buffer before the equivalent machine and the equivalent machine is in the working state.

[0090] Among them, the blocking rate of the equivalent machine represents the blocking rate of the th equivalent machine. The equivalent machine is in the working state and the equivalent machine cannot complete the assembly operation, and the number of work-in-process in the buffer has reached the maximum capacity , and the work-in-process assembled by the equivalent machine cannot be transferred out, then the equivalent machine will be in the blocked state, and the probability that the equivalent machine will be in the blocked state is the blocking rate.

[0091] The blocking rate of the equivalent machine represents the starvation rate of the th equivalent machine. The number of work-in-process in the buffer is zero, the equivalent machine cannot receive the work-in-process that can be assembled and the equivalent machine is in the working state, then the equivalent machine will be in the starvation state, and the probability that the equivalent machine will be in the starvation state is the starvation rate.

[0092] S103: Determine the bottleneck among multiple equivalent machines of the assembly line according to the blockage rate and starvation rate of the equivalent machines.

[0093] Among them, the bottleneck refers to the equivalent machine that has the greatest impact on the productivity of the assembly line. For example, if an equivalent machine has a greater impact on the productivity of the assembly line, it is very likely that this equivalent machine is in an unhealthy state. Therefore, in order to improve the productivity of the assembly line, it is necessary to identify the bottleneck among multiple equivalent machines of the assembly line.

[0094] The method for identifying the bottleneck of the assembly line based on the industrial Internet provided in this embodiment determines the failure rate and repair rate of the equivalent machine composed of each assembly machine and the corresponding line-side inventory based on the probability of the assembly machine being in the working state, the probability of the part replenishment system successfully replenishing parts for the line-side inventory, the maximum capacity of the line-side inventory, the replenishment threshold of the line-side inventory, the number of parts in the line-side inventory, the working state of the part replenishment system, and the maximum capacity of the buffer. Based on the failure rate and repair rate of the equivalent machine and the maximum capacity of the buffer, determine the blockage rate and starvation rate of the equivalent machine. Among them, the blockage rate of the equivalent machine is the probability that the buffer after the equivalent machine reaches the maximum capacity, the equivalent machine is in the working state, and the next equivalent machine of the equivalent machine cannot complete the assembly; the starvation rate of the equivalent machine is the probability that there is no work-in-process in the buffer before the equivalent machine and the equivalent machine is in the working state. According to the blockage rate and starvation rate of the equivalent machine, determine the bottleneck among multiple equivalent machines of the assembly line; this method comprehensively considers multi-dimensional parameters of the assembly machine, part replenishment system, line-side inventory, and buffer, calculates the failure rate, repair rate, blockage rate, and starvation rate of the equivalent machine, so as to accurately identify the bottleneck in the assembly line.

[0095] In a possible implementation manner, based on the probability of the assembly machine being in the working state, the probability of the part replenishment system successfully replenishing parts for the line-side inventory, the maximum capacity of the line-side inventory, the replenishment threshold of the line-side inventory, the number of parts in the line-side inventory, the working state of the part replenishment system, and the maximum capacity of the buffer, determine the failure rate and repair rate of the equivalent machine composed of each assembly machine and the corresponding line-side inventory. The specific implementation method includes:

[0096] Based on the probability of the assembly machine being in the working state, the probability of the part replenishment system successfully replenishing parts for the line-side inventory, the maximum capacity of the line-side inventory, the replenishment threshold of the line-side inventory, the number of parts in the line-side inventory, and the working state of the part replenishment system, determine the initial failure rate and initial repair rate of each equivalent machine;

[0097] Based on the assembly sequence of all equivalent machines on the assembly line, the initial failure rate and initial repair rate of each equivalent machine, and the maximum capacity of the buffer, perform at least one round of update on the initial failure rate and initial repair rate of each equivalent machine to obtain the failure rate and repair rate of each equivalent machine.

[0098] The calculation formula for the initial failure rate of the equivalent machine is:

[0099]

[0100] The calculation formula for the initial repair rate of the equivalent machine is:

[0101]

[0102] Indicates the equivalent machine In-line side inventory The number of parts is 0 and the part replenishment system is in-line side inventory The probability of normal part supply.

[0103] The calculation formula for it is:

[0104]

[0105]

[0106] Wherein, ; ; Indicates the equivalent machine The state it is in; Indicates that the part replenishment system is in-line side inventory Normal part supply; Indicates that the part replenishment system stops supplying parts to the in-line side inventory; Indicates that the equivalent machine Is in the state The probability of; Indicates the equivalent machine Is in the in-line side inventory The number of parts in it is And the part replenishment system is in-line side inventory The probability of the state of normal part supply; Indicates the equivalent machine Is in the in-line side inventory The number of parts in it is And the part replenishment system stops supplying parts to the in-line side inventory The probability of the state of;

[0107] Optionally, based on the assembly sequence of all equivalent machines on the assembly line, the initial failure rate and initial repair rate of each equivalent machine, and the maximum capacity of the buffer, perform at least one round of update on the initial failure rate and initial repair rate of each equivalent machine to obtain the failure rate and repair rate of each equivalent machine. The specific implementation method includes:

[0108] Initialize the forward aggregated failure rate and forward aggregated repair rate of the first equivalent machine, the backward aggregated failure rate and backward aggregated repair rate of the last equivalent machine, and the forward aggregated failure rate and forward aggregated repair rate of other equivalent machines except the first and the last in the first-round update, based on the assembly sequence of all equivalent machines on the assembly line;

[0109] Initialize the forward aggregated failure rate of the first equivalent machine: , ;

[0110] Initialize the forward aggregated repair rate of the first equivalent machine: , ;

[0111] Initialize the backward aggregated failure rate of the last equivalent machine: , ;

[0112] Initialize the backward aggregated repair rate of the last equivalent machine: ;

[0113] Initialize the forward aggregated failure rate of other equivalent machines except the first and the last in the first-round update: , ;

[0114] Initialize the forward aggregated repair rate of other equivalent machines except the first and the last in the first-round update: , .

[0115] In each round of update, in the order from back to front, based on the backward aggregated failure rate and backward aggregated repair rate of the first equivalent machine, the forward aggregated failure rate and forward aggregated repair rate of the second equivalent machine, the initial failure rate and initial repair rate of the second equivalent machine, and the maximum capacity of the buffer between the first equivalent machine and the second equivalent machine, determine the updated backward aggregated failure rate and backward aggregated repair rate of the second equivalent machine, where the first equivalent machine is the latter of two adjacent equivalent machines, and the second equivalent machine is the former equivalent machine of the first equivalent machine;

[0116] Expression for the updated backward aggregated failure rate of the equivalent machine:

[0117]

[0118] Expression for the updated backward aggregated repair rate of the equivalent machine:

[0119]

[0120] where, The calculation formula is:

[0121]

[0122] = ;

[0123] ;

[0124] ;

[0125] ;

[0126] ;

[0127] ;

[0128] ;

[0129] .

[0130] In the order from front to back, based on the forward aggregation failure rate and forward aggregation repair rate of the third equivalent machine, the backward aggregation failure rate and backward aggregation repair rate of the fourth equivalent machine, the initial failure rate and initial repair rate of the fourth equivalent machine, and the maximum capacity of the buffer between the third equivalent machine and the fourth equivalent machine, determine the updated forward aggregation failure rate and forward aggregation repair rate of the fourth equivalent machine, where the third equivalent machine is the previous one of two adjacent equivalent machines, and the fourth equivalent machine is the equivalent machine after the first equivalent machine;

[0131] Expression of the forward aggregation failure rate of the updated equivalent machine:

[0132]

[0133] Expression of the forward aggregation repair rate of the updated equivalent machine:

[0134]

[0135] Among them, The calculation formula is:

[0136]

[0137] ;

[0138] ;

[0139] ;

[0140] ;

[0141] ;

[0142] ;

[0143] ;

[0144] 。

[0145] Determine whether the backward aggregation failure rate, backward aggregation repair rate, forward aggregation failure rate, and forward aggregation repair rate of each equivalent machine after update meet the convergence conditions. The convergence conditions are:

[0146] , ;

[0147] , ;

[0148] , ;

[0149] , 。

[0150] If they are met, determine the backward aggregation failure rate and forward aggregation failure rate of each equivalent machine after update as the failure rate of each equivalent machine, and determine the backward aggregation repair rate and forward aggregation repair rate of each equivalent machine after update as the repair rate of each equivalent machine, that is , , , , 。If they are not met, continue to perform the next round of update.

[0151] In a possible implementation manner, based on the failure rate and repair rate of the equivalent machine and the maximum capacity of the buffer, the specific implementation manner for determining the blocking rate and starvation rate of the equivalent machine is as follows, including:

[0152] Determine the blocking rate of the fifth equivalent machine according to the initial failure rate and initial repair rate of the fifth equivalent machine, the forward aggregation failure rate and forward aggregation repair rate of the fifth equivalent machine, the backward aggregation failure rate and backward aggregation repair rate of the sixth equivalent machine, and the maximum capacity of the buffer between the fifth equivalent machine and the sixth equivalent machine, where the fifth equivalent machine is any equivalent machine except the last equivalent machine, and the sixth equivalent machine is the next equivalent machine of the fifth equivalent machine;

[0153] The calculation formula for the blocking rate of the equivalent machine is:

[0154]

[0155] Determine the starvation rate of the seventh equivalent machine based on the initial failure rate and initial repair rate of the seventh equivalent machine, the backward aggregation failure rate and backward aggregation repair rate of the seventh equivalent machine, the forward aggregation failure rate and forward aggregation repair rate of the eighth equivalent machine, and the maximum capacity of the buffer between the seventh equivalent machine and the eighth equivalent machine, where the seventh equivalent machine is any equivalent machine other than the first equivalent machine, and the eighth equivalent machine is the equivalent machine preceding the seventh equivalent machine.

[0156] The calculation formula for the starvation rate of an equivalent machine is:

[0157]

[0158] In a possible implementation, determine the bottleneck among the multiple equivalent machines of the assembly line based on the blockage rate and starvation rate of the equivalent machines, including:

[0159] For any equivalent machine other than the last equivalent machine, determine the first change rate of the productivity of the assembly line with respect to the influencing factor based on the initial failure rate and initial repair rate of the equivalent machine, the starvation rate of the next equivalent machine of the equivalent machine, the probability that the assembly machine in the equivalent machine is in the working state, the probability that the part replenishment system successfully replenishes parts for the line-side inventory in the equivalent machine, the maximum capacity of the line-side inventory in the equivalent machine, and the replenishment threshold of the line-side inventory in the equivalent machine. The influencing factor is any one of the following: the probability that the assembly machine is in the working state, the probability that the part replenishment system successfully replenishes parts for the line-side inventory, the replenishment threshold of the line-side inventory, and the maximum capacity of the line-side inventory;

[0160] The calculation formula for the first change rate of the productivity of the assembly line with respect to the influencing factor is:

[0161]

[0162] where ; is the influencing factor, is any one of the following: the probability that the assembly machine is in the working state 、the probability that the part replenishment system successfully replenishes parts for the line-side inventory 、the replenishment threshold of the line-side inventory 、the maximum capacity of the line-side inventory 。

[0163] For any equivalent machine except the first equivalent machine, determine the second rate of change of the productivity of the assembly line with respect to the influencing factor based on the initial failure rate and initial repair rate of any equivalent machine, the blocking rate of the previous equivalent machine of any equivalent machine, the probability that the assembly machine in any equivalent machine is in the working state, the probability that the part replenishment system successfully replenishes parts for the line-side inventory in any equivalent machine, the maximum capacity of the line-side inventory in any equivalent machine, and the replenishment threshold of the line-side inventory in any equivalent machine.

[0164] The formula for calculating the second rate of change of the productivity of the assembly line with respect to the influencing factor is:

[0165]

[0166] where ; is the influencing factor, is any one of the following: the probability that the assembly machine is in the working state , the probability that the part replenishment system successfully replenishes parts for the line-side inventory , the replenishment threshold of the line-side inventory , the maximum capacity of the line-side inventory .

[0167] Determine the bottleneck among multiple equivalent machines of the assembly line according to the first rate of change and the second rate of change.

[0168] Optionally, the specific implementation method for determining the bottleneck among multiple equivalent machines of the assembly line according to the first rate of change and the second rate of change includes:

[0169] For the first equivalent machine, if the first rate of change corresponding to the first equivalent machine is greater than the second rate of change corresponding to the second equivalent machine, then the first equivalent machine is the bottleneck;

[0170] where the first rate of change corresponding to the first equivalent machine is , and the second rate of change corresponding to the second equivalent machine is .

[0171] If , then the equivalent machine is the bottleneck.

[0172] For any equivalent machine except the first equivalent machine and the last equivalent machine, if the first rate of change corresponding to any equivalent machine is greater than the second rate of change corresponding to the next equivalent machine of any equivalent machine, and the second rate of change corresponding to any equivalent machine is greater than the first rate of change corresponding to the previous equivalent machine of any equivalent machine, then any equivalent machine is the bottleneck;

[0173] where the first rate of change corresponding to any equivalent machine is The second change rate corresponding to the next equivalent machine of any equivalent machine is The second change rate corresponding to any equivalent machine is The first change rate corresponding to the previous equivalent machine of any equivalent machine is .

[0174] If and then the equivalent machine is the bottleneck, where .

[0175] Assume that the influence factor is the probability that the assembly machine is in the working state , , , , , , , = 0.4862, , , , , then , , , , , then, the equivalent machines and are the bottlenecks.

[0176] For the last equivalent machine, if the second change rate corresponding to the last equivalent machine is greater than the first change rate corresponding to the penultimate equivalent machine, then the last equivalent machine is the bottleneck.

[0177] Among them, the second change rate corresponding to the last equivalent machine is , and the first change rate corresponding to the penultimate equivalent machine is .

[0178] If then the equivalent machine is the bottleneck.

[0179] In a possible implementation manner, when there are multiple bottlenecks on the assembly line, the bottleneck severity scores corresponding to each bottleneck are determined according to the first change rate and the second change rate, and the bottleneck with the maximum bottleneck severity score is determined as the core bottleneck of the assembly line.

[0180] Optionally, the specific implementation manner of determining the bottleneck severity scores corresponding to each bottleneck according to the first change rate and the second change rate includes:

[0181] In the case where the first equivalent machine is the bottleneck, the absolute value of the difference between the first change rate corresponding to the first equivalent machine and the second change rate corresponding to the second equivalent machine is used to determine the bottleneck severity score corresponding to the first equivalent machine;

[0182] wherein, the first change rate corresponding to the first equivalent machine is , and the second change rate corresponding to the second equivalent machine is , and the bottleneck severity score corresponding to the first equivalent machine is .

[0183] The calculation formula for the bottleneck severity score corresponding to the first equivalent machine is:

[0184]

[0185] In the case where any equivalent machine except the first equivalent machine and the last equivalent machine is the bottleneck, the sum of the absolute value of the difference between the first change rate corresponding to any equivalent machine and the second change rate corresponding to the next equivalent machine of any equivalent machine, and the absolute value of the difference between the second change rate corresponding to any equivalent machine and the first change rate corresponding to the previous equivalent machine of any equivalent machine is determined as the bottleneck severity score corresponding to any equivalent machine;

[0186] wherein, the first change rate corresponding to any equivalent machine is , the second change rate corresponding to the next equivalent machine of any equivalent machine is , the second change rate corresponding to any equivalent machine is , the first change rate corresponding to the previous equivalent machine of any equivalent machine is , and the bottleneck severity score corresponding to any equivalent machine is .

[0187] The calculation formula for the bottleneck severity score corresponding to any equivalent machine is:

[0188]

[0189] Assume that the influence factor is the probability that the assembly machine is in the working state , , , , , , , = 0.4862, , , , , , , , , , , , equivalent machine and is the bottleneck.

[0190] = , = ,

[0191]

[0192] Then, the core bottleneck of the assembly line is .

[0193] In the case where the last equivalent machine is the bottleneck, the absolute value of the difference between the second change rate corresponding to the last equivalent machine and the first change rate corresponding to the penultimate equivalent machine is determined as the bottleneck severity score corresponding to the last equivalent machine.

[0194] Among them, the second change rate corresponding to the last equivalent machine is , and the first change rate corresponding to the penultimate equivalent machine is , and the bottleneck severity score corresponding to the last equivalent machine is .

[0195] The calculation formula for the bottleneck severity score corresponding to the last equivalent machine is:[[]]

[0196]

[0197] Figure 3 is the structural schematic diagram of the assembly line bottleneck identification device based on industrial Internet provided by this application. As Figure 3 shown, the assembly line bottleneck identification device 200 based on industrial Internet provided in this embodiment includes:[[]]

[0198] Determination module 201, configured to determine the failure rate and repair rate of the equivalent machine composed of each assembly machine and the corresponding line-side inventory based on the probability that the assembly machine is in the working state, the probability that the part replenishment system successfully replenishes parts for the line-side inventory, the maximum capacity of the line-side inventory, the replenishment threshold of the line-side inventory, the number of parts in the line-side inventory, the working state of the part replenishment system, and the maximum capacity of the buffer.[[]]

[0199] The determination module 201 is further configured to determine the blocking rate and starvation rate of the equivalent machine based on the failure rate and repair rate of the equivalent machine and the maximum capacity of the buffer, where the blocking rate of the equivalent machine is the probability that the buffer after the equivalent machine reaches the maximum capacity, the equivalent machine is in the working state, and the next equivalent machine of the equivalent machine cannot complete the assembly; the starvation rate of the equivalent machine is the probability that there is no work-in-progress in the buffer before the equivalent machine and the equivalent machine is in the working state;

[0200] The determination module 201 is further configured to determine the bottleneck among the multiple equivalent machines of the assembly line according to the blocking rate and starvation rate of the equivalent machine.

[0201] In a possible implementation manner, the determination module 201 is further configured to determine the initial failure rate and initial repair rate of each equivalent machine based on the probability that the assembly machine is in the working state, the probability that the part replenishment system successfully replenishes parts for the line-side inventory, the maximum capacity of the line-side inventory, the replenishment threshold of the line-side inventory, the number of parts in the line-side inventory, and the working state of the part replenishment system;

[0202] The determination module 201 is further configured to perform at least one round of update on the initial failure rate and initial repair rate of each equivalent machine based on the assembly sequence of all the equivalent machines on the assembly line, the initial failure rate and initial repair rate of each equivalent machine, and the maximum capacity of the buffer, so as to obtain the failure rate and repair rate of each equivalent machine.

[0203] In a possible implementation manner, the assembly line bottleneck identification device based on the industrial Internet further includes: a processing module 202 and a judgment module 203;

[0204] The processing module 202 is configured to initialize the forward aggregated failure rate and forward aggregated repair rate of the first equivalent machine, the backward aggregated failure rate and backward aggregated repair rate of the last equivalent machine, and the forward aggregated failure rate and forward aggregated repair rate of the other equivalent machines except the first and the last in the first round of update based on the assembly sequence of all the equivalent machines on the assembly line;

[0205] The determination module 201 is further configured to, in each round of update, in the reverse order, based on the backward aggregated failure rate and backward aggregated repair rate of the first equivalent machine, the forward aggregated failure rate and forward aggregated repair rate of the second equivalent machine, the initial failure rate and initial repair rate of the second equivalent machine, and the maximum capacity of the buffer between the first equivalent machine and the second equivalent machine, determine the backward aggregated failure rate and backward aggregated repair rate of the updated second equivalent machine, and, in the forward order, based on the forward aggregated failure rate and forward aggregated repair rate of the third equivalent machine, the backward aggregated failure rate and backward aggregated repair rate of the fourth equivalent machine, the initial failure rate and initial repair rate of the fourth equivalent machine, and the maximum capacity of the buffer between the third equivalent machine and the fourth equivalent machine, determine the forward aggregated failure rate and forward aggregated repair rate of the updated fourth equivalent machine, where the first equivalent machine is the latter one of two adjacent equivalent machines, the second equivalent machine is the previous equivalent machine of the first equivalent machine, the third equivalent machine is the previous one of two adjacent equivalent machines, and the fourth equivalent machine is the latter equivalent machine of the first equivalent machine;

[0206] The judgment module 203 is configured to judge whether the backward aggregated failure rate, backward aggregated repair rate, forward aggregated failure rate, and forward aggregated repair rate of each updated equivalent machine satisfy the convergence condition;

[0207] The determination module 201 is further configured to, if satisfied, determine the backward aggregated failure rate and forward aggregated failure rate of each updated equivalent machine as the failure rate of each equivalent machine, and determine the backward aggregated repair rate and forward aggregated repair rate of each updated equivalent machine as the repair rate of each equivalent machine, and if not satisfied, continue to perform the next round of update.

[0208] In a possible implementation manner, the determination module 201 is further configured to determine the blocking rate of the fifth equivalent machine according to the initial failure rate and initial repair rate of the fifth equivalent machine, the forward aggregated failure rate and forward aggregated repair rate of the fifth equivalent machine, the backward aggregated failure rate and backward aggregated repair rate of the sixth equivalent machine, and the maximum capacity of the buffer between the fifth equivalent machine and the sixth equivalent machine, where the fifth equivalent machine is any equivalent machine except the last equivalent machine, and the sixth equivalent machine is the next equivalent machine of the fifth equivalent machine;

[0209] The determination module 201 is further configured to determine the starvation rate of the seventh equivalent machine according to the initial failure rate and initial repair rate of the seventh equivalent machine, the backward aggregated failure rate and backward aggregated repair rate of the seventh equivalent machine, the forward aggregated failure rate and forward aggregated repair rate of the eighth equivalent machine, and the maximum capacity of the buffer between the seventh equivalent machine and the eighth equivalent machine, where the seventh equivalent machine is any equivalent machine except the first equivalent machine, and the eighth equivalent machine is the previous equivalent machine of the seventh equivalent machine.

[0210] In a possible implementation, the determining module 201 is further configured to, for any equivalent machine except the last equivalent machine, determine a first change rate of the productivity of the assembly line with respect to an influencing factor according to the initial failure rate and initial repair rate of any equivalent machine, the starvation rate of the next equivalent machine of any equivalent machine, the probability that the assembly machine in any equivalent machine is in a working state, the probability that the part replenishment system successfully replenishes parts for the line-side inventory in any equivalent machine, the maximum capacity of the line-side inventory in any equivalent machine, and the replenishment threshold of the line-side inventory in any equivalent machine, where the influencing factor is any one of the following: the probability that the assembly machine is in a working state, the probability that the part replenishment system successfully replenishes parts for the line-side inventory, the replenishment threshold of the line-side inventory, and the maximum capacity of the line-side inventory;

[0211] The determining module 201 is further configured to, for any equivalent machine except the first equivalent machine, determine a second change rate of the productivity of the assembly line with respect to an influencing factor according to the initial failure rate and initial repair rate of any equivalent machine, the blocking rate of the previous equivalent machine of any equivalent machine, the probability that the assembly machine in any equivalent machine is in a working state, the probability that the part replenishment system successfully replenishes parts for the line-side inventory in any equivalent machine, the maximum capacity of the line-side inventory in any equivalent machine, and the replenishment threshold of the line-side inventory in any equivalent machine;

[0212] The determining module 201 is further configured to determine a bottleneck among multiple equivalent machines of the assembly line according to the first change rate and the second change rate.

[0213] In a possible implementation, the determining module 201 is further configured to, for the first equivalent machine, if the first change rate corresponding to the first equivalent machine is greater than the second change rate corresponding to the second equivalent machine, then the first equivalent machine is the bottleneck;

[0214] The determining module 201 is further configured to, for any equivalent machine except the first equivalent machine and the last equivalent machine, if the first change rate corresponding to any equivalent machine is greater than the second change rate corresponding to the next equivalent machine of any equivalent machine, and the second change rate corresponding to any equivalent machine is greater than the first change rate corresponding to the previous equivalent machine of any equivalent machine, then any equivalent machine is the bottleneck;

[0215] The determining module 201 is further configured to, for the last equivalent machine, if the second change rate corresponding to the last equivalent machine is greater than the first change rate corresponding to the penultimate equivalent machine, then the last equivalent machine is the bottleneck.

[0216] In a possible implementation, the determining module 201 is further configured to, when there are multiple bottlenecks on the assembly line, determine the bottleneck severity score corresponding to each bottleneck according to the first change rate and the second change rate, and determine the bottleneck with the largest bottleneck severity score as the core bottleneck of the assembly line.

[0217] In a possible implementation, the determining module 201 is further configured to, when the first equivalent machine is the bottleneck, determine the absolute value of the difference between the first change rate corresponding to the first equivalent machine and the second change rate corresponding to the second equivalent machine as the bottleneck severity score corresponding to the first equivalent machine;

[0218] The determining module 201 is further configured to, when any equivalent machine other than the first equivalent machine and the last equivalent machine is the bottleneck, determine the sum of the absolute value of the difference between the first change rate corresponding to any equivalent machine and the second change rate corresponding to the next equivalent machine of any equivalent machine, and the absolute value of the difference between the second change rate corresponding to any equivalent machine and the first change rate corresponding to the previous equivalent machine of any equivalent machine as the bottleneck severity score corresponding to any equivalent machine;

[0219] The determining module 201 is further configured to, when the last equivalent machine is the bottleneck, determine the absolute value of the difference between the second change rate corresponding to the last equivalent machine and the first change rate corresponding to the penultimate equivalent machine as the bottleneck severity score corresponding to the last equivalent machine.

[0220] The assembly line bottleneck identification device based on the industrial Internet provided in this embodiment can execute the method provided in the above method embodiment, and its implementation principle and technical effect are similar, which will not be elaborated here in this embodiment.

[0221] Figure 4 It is a schematic structural diagram of the assembly line bottleneck identification device based on the industrial Internet provided by this application. As Figure 4 shown, the electronic device 300 provided in this embodiment includes: at least one processor 301 and a memory 302. Optionally, the device 30 further includes a communication component 303. Among them, the processor 301, the memory 302, and the communication component 303 are connected through a bus 304.

[0222] In a specific implementation process, at least one processor 301 executes the computer execution instructions stored in the memory 302, so that at least one processor 301 executes the above method.

[0223] The specific implementation process of the processor 301 can refer to the above method embodiment, and its implementation principle and technical effect are similar, which will not be elaborated here in this embodiment.

[0224] In the above embodiments, it should be understood that the processor may be a central processing unit (CPU for short), or other general-purpose processors, digital signal processors (DSP for short), application specific integrated circuits (ASIC for short), etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the method disclosed in combination with the invention can be directly implemented by the execution of the hardware processor, or implemented by the combination of hardware and software modules in the processor.

[0225] The memory may include a high-speed random access memory (RAM), and may also include non-volatile memory (NVM), such as at least one disk memory.

[0226] The bus may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For the convenience of representation, the bus in the drawings of this application is not limited to only one bus or one type of bus.

[0227] This application also provides a computer program product, including a computer program, which implements the above method when executed by a processor.

[0228] This application also provides a computer-readable storage medium, in which computer-executable instructions are stored, and when the processor executes the computer-executable instructions, the above method is implemented.

[0229] The above-readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, a magnetic disk or an optical disc. The readable storage medium can be any available medium accessible by a general-purpose or special-purpose computer.

[0230] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can be located in an Application Specific Integrated Circuits (ASIC). Of course, the processor and the readable storage medium can also exist as discrete components in a device.

[0231] The division of units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Additionally, the couplings or direct couplings or communication connections shown or discussed among each other can be indirect couplings or communication connections through some interfaces, devices or units, and can be in electrical, mechanical or other forms.

[0232] The units described as separate components may or may not be physically separated. The components shown as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0233] In addition, in each embodiment of the present invention, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0234] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods in each embodiment of the present invention. The aforementioned storage medium includes various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs.

[0235] Those of ordinary skill in the art will understand that all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments; and the aforementioned storage medium includes: various media such as ROM, RAM, magnetic disks, or optical discs that can store program codes.

[0236] Finally, it should be noted that: After considering the specification and practicing the invention disclosed herein, those skilled in the art will readily think of other embodiments of the present invention. The present invention is intended to cover any variations, uses, or adaptations of the present invention, which follow the general principles of the present invention and include known common knowledge or conventional technical means in the technical field not disclosed by the present invention. It is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope.

Claims

1. An assembly line bottleneck identification method based on the industrial Internet, characterized in that, The assembly line includes a plurality of assembly machines that sequentially perform different part assemblies. Each of the assembly machines has a corresponding in-line inventory, which is used to store the parts corresponding to the assembly machine. The parts in the in-line inventory are replenished by a corresponding part replenishment system. There is a buffer between two of the assembly machines, and the buffer is used to store work-in-progress; the method includes: Based on the probability that the assembly machine is in a working state, the probability that the part replenishment system successfully replenishes parts to the in-line inventory, the maximum capacity of the in-line inventory, the replenishment threshold of the in-line inventory, the number of parts in the in-line inventory, the working state of the part replenishment system, and the maximum capacity of the buffer, determine the failure rate and repair rate of the equivalent machine formed by each of the assembly machines and the corresponding in-line inventory; Based on the failure rate and repair rate of the equivalent machine and the maximum capacity of the buffer, determine the blocking rate and starvation rate of the equivalent machine. Among them, the blocking rate of the equivalent machine is the probability that the buffer after the equivalent machine reaches the maximum capacity, the equivalent machine is in a working state, and the next equivalent machine of the equivalent machine cannot complete the assembly; the starvation rate of the equivalent machine is the probability that there is no work-in-progress in the buffer before the equivalent machine and the equivalent machine is in a working state; According to the blocking rate and starvation rate of the equivalent machine, determine the bottleneck among the multiple equivalent machines of the assembly line; The determining the bottleneck among the multiple equivalent machines of the assembly line according to the blocking rate and starvation rate of the equivalent machine includes: For any equivalent machine except the last one, according to the initial failure rate and initial repair rate of the equivalent machine, the starvation rate of the next equivalent machine of the equivalent machine, the probability that the assembly machine in the equivalent machine is in a working state, the probability that the part replenishment system successfully replenishes parts to the in-line inventory in the equivalent machine, the maximum capacity of the in-line inventory in the equivalent machine, and the replenishment threshold of the in-line inventory in the equivalent machine, determine the first change rate of the productivity of the assembly line with respect to the influencing factor, where the influencing factor is any one of the following: the probability that the assembly machine is in a working state, the probability that the part replenishment system successfully replenishes parts to the in-line inventory, the replenishment threshold of the in-line inventory, and the maximum capacity of the in-line inventory; For any equivalent machine except the first one, according to the initial failure rate and initial repair rate of the equivalent machine, the blocking rate of the previous equivalent machine of the equivalent machine, the probability that the assembly machine in the equivalent machine is in a working state, the probability that the part replenishment system successfully replenishes parts to the in-line inventory in the equivalent machine, the maximum capacity of the in-line inventory in the equivalent machine, and the replenishment threshold of the in-line inventory in the equivalent machine, determine the second change rate of the productivity of the assembly line with respect to the influencing factor; According to the first change rate and the second change rate, determine the bottleneck among the multiple equivalent machines of the assembly line.

2. The method according to claim 1, wherein Determining the failure rate and repair rate of an equivalent machine composed of each of the assembly machines and the corresponding line-side inventory based on the probability that the assembly machine is in a working state, the probability that the part replenishment system successfully replenishes parts to the line-side inventory, the maximum capacity of the line-side inventory, the replenishment threshold of the line-side inventory, the number of parts in the line-side inventory, the working state of the part replenishment system, and the maximum capacity of the buffer, includes: Based on the probability that the assembly machine is in a working state, the probability that the part replenishment system successfully replenishes parts to the line-side inventory, the maximum capacity of the line-side inventory, the replenishment threshold of the line-side inventory, the number of parts in the line-side inventory, and the working state of the part replenishment system, determining the initial failure rate and initial repair rate of each of the equivalent machines; Based on the assembly sequence of all the equivalent machines on the assembly line, the initial failure rate and initial repair rate of each of the equivalent machines, and the maximum capacity of the buffer, performing at least one round of update on the initial failure rate and initial repair rate of each of the equivalent machines to obtain the failure rate and repair rate of each of the equivalent machines.

3. The method according to claim 2, characterized in that The performing at least one round of update on the initial failure rate and initial repair rate of each of the equivalent machines based on the assembly sequence of all the equivalent machines on the assembly line, the initial failure rate and initial repair rate of each of the equivalent machines, and the maximum capacity of the buffer to obtain the failure rate and repair rate of each of the equivalent machines includes: Based on the assembly sequence of all the equivalent machines on the assembly line, initializing the forward aggregated failure rate and forward aggregated repair rate of the first equivalent machine, the backward aggregated failure rate and backward aggregated repair rate of the last equivalent machine, and the forward aggregated failure rate and forward aggregated repair rate of other equivalent machines except the first and the last in the first round of update; In each round of update, in the order from back to front, based on the backward aggregated failure rate and backward aggregated repair rate of the first equivalent machine, the forward aggregated failure rate and forward aggregated repair rate of the second equivalent machine, the initial failure rate and initial repair rate of the second equivalent machine, and the maximum capacity of the buffer between the first equivalent machine and the second equivalent machine, determining the updated backward aggregated failure rate and backward aggregated repair rate of the second equivalent machine, and, in the order from front to back, based on the forward aggregated failure rate and forward aggregated repair rate of the third equivalent machine, the backward aggregated failure rate and backward aggregated repair rate of the fourth equivalent machine, the initial failure rate and initial repair rate of the fourth equivalent machine, and the maximum capacity of the buffer between the third equivalent machine and the fourth equivalent machine, determining the updated forward aggregated failure rate and forward aggregated repair rate of the fourth equivalent machine, where the first equivalent machine is the latter one of two adjacent equivalent machines, the second equivalent machine is the previous equivalent machine of the first equivalent machine, the third equivalent machine is the previous one of two adjacent equivalent machines, and the fourth equivalent machine is the latter one of the first equivalent machine; Determine whether the backward aggregation failure rate, backward aggregation repair rate, forward aggregation failure rate, and forward aggregation repair rate of each updated equivalent machine meet the convergence condition. If they meet, determine the backward aggregation failure rate and forward aggregation failure rate of each updated equivalent machine as the failure rate of each equivalent machine, and determine the backward aggregation repair rate and forward aggregation repair rate of each updated equivalent machine as the repair rate of each equivalent machine. If they do not meet, continue to perform the next round of update.

4. The method according to claim 3, characterized in that, Based on the failure rate and repair rate of the equivalent machine and the maximum capacity of the buffer, determining the blocking rate and starvation rate of the equivalent machine includes: Determine the blocking rate of the fifth equivalent machine according to the initial failure rate and initial repair rate of the fifth equivalent machine, the forward aggregation failure rate and forward aggregation repair rate of the fifth equivalent machine, the backward aggregation failure rate and backward aggregation repair rate of the sixth equivalent machine, and the maximum capacity of the buffer between the fifth equivalent machine and the sixth equivalent machine, where the fifth equivalent machine is any equivalent machine except the last equivalent machine, and the sixth equivalent machine is the next equivalent machine of the fifth equivalent machine; Determine the starvation rate of the seventh equivalent machine according to the initial failure rate and initial repair rate of the seventh equivalent machine, the backward aggregation failure rate and backward aggregation repair rate of the seventh equivalent machine, the forward aggregation failure rate and forward aggregation repair rate of the eighth equivalent machine, and the maximum capacity of the buffer between the seventh equivalent machine and the eighth equivalent machine, where the seventh equivalent machine is any equivalent machine except the first equivalent machine, and the eighth equivalent machine is the previous equivalent machine of the seventh equivalent machine.

5. The method according to claim 3 or 4, characterized in that, The determining of the bottleneck among the multiple equivalent machines of the assembly line according to the first change rate and the second change rate includes: For the first equivalent machine, if the first change rate corresponding to the first equivalent machine is greater than the second change rate corresponding to the second equivalent machine, then the first equivalent machine is the bottleneck; For any equivalent machine except the first equivalent machine and the last equivalent machine, if the first change rate corresponding to the any equivalent machine is greater than the second change rate corresponding to the next equivalent machine of the any equivalent machine, and the second change rate corresponding to the any equivalent machine is greater than the first change rate corresponding to the previous equivalent machine of the any equivalent machine, then the any equivalent machine is the bottleneck; For the last equivalent machine, if the second change rate corresponding to the last equivalent machine is greater than the first change rate corresponding to the penultimate equivalent machine, then the last equivalent machine is the bottleneck.

6. The method according to claim 5, wherein It further includes: In the case where there are multiple bottlenecks in the assembly line, determine the bottleneck severity score corresponding to each bottleneck according to the first change rate and the second change rate, and determine the bottleneck with the largest bottleneck severity score as the core bottleneck of the assembly line.

7. The method according to claim 6, characterized in that, The determining of the bottleneck severity score corresponding to each bottleneck according to the first change rate and the second change rate includes: In the case where the first equivalent machine is the bottleneck, the absolute value of the difference between the first change rate corresponding to the first equivalent machine and the second change rate corresponding to the second equivalent machine is used to determine the bottleneck severity score corresponding to the first equivalent machine; In the case where any equivalent machine other than the first equivalent machine and the last equivalent machine is the bottleneck, the sum of the absolute value of the difference between the first change rate corresponding to the any equivalent machine and the second change rate corresponding to the next equivalent machine of the any equivalent machine, and the absolute value of the difference between the second change rate corresponding to the any equivalent machine and the first change rate corresponding to the previous equivalent machine of the any equivalent machine is determined as the bottleneck severity score corresponding to the any equivalent machine; In the case where the last equivalent machine is the bottleneck, the absolute value of the difference between the second change rate corresponding to the last equivalent machine and the first change rate corresponding to the penultimate equivalent machine is determined as the bottleneck severity score corresponding to the last equivalent machine.

8. An assembly line bottleneck recognition device based on the industrial Internet, characterized in that Comprising: A memory, a processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory, so that the processor executes the method according to any one of claims 1-7.

9. A computer-readable storage medium, characterized in that, Computer-executable instructions are stored in the computer-readable storage medium, and when the computer-executable instructions are executed by a processor, they are used to implement the method according to any one of claims 1-7.

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