Reusable product maintenance strategy optimization method, equipment and medium

Abstract

The invention relates to the technical field of maintenance guarantee, in particular to a reusable product maintenance strategy optimization method, equipment and a medium, which can give a reasonable period of preventive maintenance, improve the maintenance work efficiency and reduce the waste of maintenance resources. According to the method, the fault rate change of the reusable product after repeated use and repair is described by constructing the fault rate function of the reusable product, the change condition of the fault rate caused by repeated use of the product is analyzed, and the accumulated cost of repeated preventive maintenance of the product is sorted; the cost-effectiveness ratio of multiple preventive maintenance modes of the reusable product is measured through the ratio of the maintenance cost to the fault rate change, so that the maintenance strategy with the optimal maintenance cost-effectiveness ratio of the reusable product is judged, the reasonable period of preventive maintenance is finally given, the maintenance work efficiency is improved, and the waste of maintenance resources is reduced.

Description

Technical Field

[0001] The present invention relates to the field of maintenance guarantee technology, and specifically to a method, device and medium for optimizing a maintenance strategy for a reusable product. Background Art

[0002] At present, the formulation of maintenance strategies for reusable products lacks scientific theoretical basis. When repairing or repairing products that are in use or to be reused, the main maintenance system is based on regular maintenance and post-maintenance. Among them, regular maintenance adopts the principles of more (more maintenance times), more frequent (more frequent inspections), and more detailed (detailed maintenance items) to repair and maintain reusable products. Post-maintenance, also known as post-failure maintenance, refers to the use of corresponding maintenance methods to repair products when unexpected failures and damages occur. It is an unplanned maintenance method that is only applicable to equipment units with less impact from failures, otherwise it may cause catastrophic accidents. The above two maintenance methods are prone to over-maintenance and under-maintenance, resulting in a waste of maintenance resources.

[0003] It can be seen that the existing maintenance strategy for reusable products mainly adopts a maintenance system based on regular maintenance and post-maintenance. Among them, regular maintenance adopts the principles of more (more maintenance times), more frequent (more frequent inspections), and more detailed (detailed maintenance items) to repair and maintain reusable products, which is prone to over-maintenance; post-maintenance is to use corresponding maintenance methods to repair the product when unexpected failures and damage occur, which is prone to under-maintenance. It is an unplanned maintenance method. This method is only applicable to equipment units with less impact from failures, otherwise it may cause catastrophic accidents. The existing maintenance strategy is aimed at ensuring success, and often does not fully consider cost issues, resulting in a waste of maintenance resources. Summary of the invention

[0004] In view of this, the present invention provides a method, device and medium for optimizing maintenance strategy of reusable products, which can provide a reasonable cycle of preventive maintenance, improve maintenance work efficiency and reduce waste of maintenance resources.

[0005] (Consistent with the claims)

[0006] Beneficial effects:

[0007] 1. The present invention is a maintenance strategy optimization method for reusable products based on cost-effectiveness. The method describes the change in failure rate of reusable products after multiple uses and repairs by constructing a failure rate function of reusable products, analyzes the change in failure rate caused by multiple uses of products, and sorts out the cumulative cost of multiple preventive maintenance of products. The cost-effectiveness of various preventive maintenance methods for reusable products is measured by the ratio of maintenance cost to failure rate change, so as to determine the maintenance strategy with the best cost-effectiveness of reusable products, and finally gives a reasonable cycle of preventive maintenance, thereby improving maintenance work efficiency and reducing waste of maintenance resources.

[0008] 2. In the present invention, the monitoring parameters of the reusable products are processed by trend filtering technology to optimize the timing of preventive maintenance (preventive repair, preventive replacement), and finally a preventive maintenance strategy selection criterion based on cost-effectiveness is constructed to determine the maintenance strategy with the best cost-effectiveness for the reusable products. Among them, the monitoring data of the reusable products are smoothed by trend filtering technology to reduce the problems of untimely alarm and repeated crossing of the alarm line in the conventional fixed threshold line fault alarm method, thereby reducing the false alarm rate and false alarm rate of preventive maintenance.

[0009] 3. The method of the present invention constructs a failure rate function and a maintenance cost calculation formula for reusable products, defines a cost-effectiveness formula based on the ratio of maintenance cost to failure rate change, and introduces the concept of cost-effectiveness to judge the pros and cons of preventive maintenance methods; introduces a preventive maintenance (repair or replacement) maintenance system driven by reusable product monitoring parameters, and uses trend filtering technology to extract basic trends of monitoring parameters, reduce false alarms, more accurately judge the timing of preventive maintenance, and select preventive maintenance methods with higher cost-effectiveness, which can effectively improve maintenance work efficiency and reduce waste of maintenance resources.

[0010] 4. The device of the present invention is used to implement the method of the present invention, which describes the change in failure rate of a reusable product after multiple uses and repairs by constructing a failure rate function of the reusable product, analyzes the change in failure rate caused by multiple uses of the product, and sorts out the cumulative cost of multiple preventive maintenance of the product; measures the cost-effectiveness of various preventive maintenance methods for the reusable product by the ratio of maintenance cost to failure rate change, thereby determining the maintenance strategy with the best cost-effectiveness for the reusable product, and finally providing a reasonable cycle of preventive maintenance, thereby improving maintenance work efficiency and reducing waste of maintenance resources.

[0011] 5. The medium of the present invention is used to implement the method of the present invention, which describes the change in the failure rate of a reusable product after multiple uses and repairs by constructing a failure rate function of a reusable product, analyzes the change in the failure rate caused by multiple uses of the product, and sorts out the cumulative cost of multiple preventive maintenance of the product; measures the cost-effectiveness of various preventive maintenance methods for the reusable product by the ratio of maintenance cost to failure rate change, thereby determining the maintenance strategy with the best cost-effectiveness for the reusable product, and finally providing a reasonable cycle of preventive maintenance, thereby improving maintenance work efficiency and reducing waste of maintenance resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The figure is a flow chart of a method according to an embodiment of the present invention.

[0013] Figure 2 It is a schematic diagram showing the curve of the repeated use of product monitoring data after trend filtering in an embodiment of the present invention, and the advantages of its effect compared with the traditional conventional alarm method.

[0014] Figure 3 Schematic diagram of preventive maintenance method criteria for reusable products according to an embodiment of the present invention.

[0015] Figure 4 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0016] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0017] The present invention provides a maintenance strategy optimization method for reusable products based on cost-effectiveness. First, a failure rate function of reusable products is constructed to describe the change in failure rate after the product is used multiple times. Then, the product maintenance cost composition is sorted out, and a cost-effectiveness formula is defined using the ratio of maintenance cost to failure rate change. The principle of selecting a preventive maintenance method (repair or replacement) is formulated. Then, a trend filtering technology is used to optimize the fluctuation curve of monitoring parameters of reusable products, reduce erroneous maintenance or over-maintenance in preventive maintenance, clarify the timing and means of preventive maintenance of reusable products, and optimize the maintenance strategy of reusable products.

[0018] Specifically, the method of the present invention constructs a failure rate function and a maintenance cost calculation formula based on the use and maintenance characteristics of reusable products, and defines a cost-effectiveness formula based on the ratio of maintenance cost to failure rate change. Different from conventional regular maintenance and post-maintenance methods, the method determines the choice of preventive maintenance methods (repair or replacement) for reusable products based on the cost-effectiveness ratio, thereby optimizing the maintenance strategy of reusable products. In addition, the present invention optimizes the fluctuation curve of monitoring parameters of reusable products through trend filtering technology, reduces false alarms and false alarms that occur in the process of determining the timing of preventive maintenance, can improve maintenance work efficiency, and reduce maintenance resource waste. The process is as follows: Figure 1 As shown, the following steps are included:

[0019] Step 1: Develop a repeated use product failure rate function.

[0020] Specifically, for reusable products, they need to be repaired after each use to restore them to a usable level. However, after each maintenance, the product will not be restored to its original state. The failure rate of reusable products tends to increase with the increase in the number of maintenance times. The preventive maintenance means defined in the method of the present invention are divided into two types: preventive maintenance and preventive replacement. Therefore, the failure rate function of reusable products is constructed as:

[0021] λ i+1 (t) = m i λ i (t+n i T i ),0 <t<T i+1

[0022] Where, T i is the time interval between the ith preventive maintenance and the last maintenance, n i is the service age factor (0 <n i <1), which means that as the cumulative usage time of a reusable product increases, the failure rate during the i+1th preventive maintenance will be higher than the failure rate during the ith preventive maintenance; m i is the failure rate increasing factor (m i ≥1), which means that the failure rate growth rate of the reused product after the i+1th preventive maintenance will be higher than the failure rate growth rate during the i-th preventive maintenance. i and m i The value of needs to be derived based on the summary of the product's historical maintenance and guarantee data.

[0023] Step 2, calculate the preventive maintenance cost of the reusable product, where the preventive maintenance cost for the reusable product mainly includes the labor cost, tool cost and spare parts cost, etc., which are usually affected by the maintenance cycle and maintenance frequency. Specifically, the preventive maintenance cost calculation of the reusable product in this embodiment is implemented by the following steps:

[0024] Step 21, define the cost of product preventive maintenance. and Represent the average cost of one preventive maintenance and one preventive replacement respectively. If N preventive maintenance operations are performed on a reusable product (preventive maintenance is performed for the first N-1 times and preventive replacement is performed for the Nth time), then:

[0025]

[0026] Step 22, define the loss when the product is downtime. When the reusable product is in downtime, it will incur a certain economic loss, and the downtime caused by the preventive maintenance of the reusable product is M t for:

[0027]

[0028] In the formula, C s is the downtime cost rate per unit time of the reused product; and Respectively represent the average time for a preventive maintenance and a preventive replacement of the product.

[0029] Step 23, define the total cost of reusing products for preventive maintenance as:

[0030]

[0031] Step 3, obtain the cost-effectiveness of the preventive maintenance of the reusable product, as follows:

[0032] Preventive maintenance is performed on reusable products. After maintenance, the failure rate of the product is reduced, but it will not drop to 0. The failure rate of the product before and after maintenance is shown in the following formula:

[0033]

[0034] Failure rates of reused products are reduced through preventive maintenance:

[0035]

[0036] If preventive replacement is performed on reusable products, the equipment failure rate will drop to 0 after replacement. The failure rates of the products before and after replacement are shown below.

[0037]

[0038] Failure rates of reused products are reduced through preventive replacement:

[0039]

[0040] With Δλ i (t) represents the decrease in failure rate, and the cost-effectiveness of the reusable product after preventive maintenance can be expressed as:

[0041]

[0042] In the formula, when k p 1 >k p 2 When k p 1 ≤k p 2 Perform preventive maintenance on the product when necessary.

[0043] Select the preventive maintenance method for reusable products based on the cost-effectiveness. Preventive maintenance and preventive replacement can reduce the failure rate of reusable products. In the actual maintenance process, when the cost of repairing the product is too high, replacement will be chosen.

[0044] Furthermore, the present invention also smoothes the monitoring data of reusable products through l1 trend filtering technology, reduces the problems of untimely alarm and repeated crossing of alarm lines in conventional fixed threshold line fault alarm methods, and reduces the false alarm rate and false alarm rate of preventive maintenance. The specific implementation steps are as follows:

[0045] Step 41, smooth the monitoring data of the reused product by using the l1 trend filtering technology. After the trend data of the monitoring parameters of the reused product are processed by the l1 trend filtering, the real data development trend of the product can be obtained. Assume that the standard time series y j (j=1,…,n) is the basic trend x j and the random variable z j The purpose of trend filtering is to estimate the basic trend x of the standard time series. j , or estimate the random variable z of the standard time series j =y j -x j process.

[0046] The l1 trend filtering is achieved by minimizing the weighted objective function, which is:

[0047]

[0048] When the weighted objective function takes the minimum value, the basic trend of the reused product monitoring data can be estimated.

[0049] The matrix form of the above formula is:

[0050]

[0051] Where y=(y1,y2,…,y n )∈R n ,x=(x1,x2,…,x n )∈R n ,||u||1=Σ j u j represents the l1 norm of vector u, D∈R (n-2)×n is a second-order difference matrix:

[0052]

[0053] a is a non-negative parameter that controls the smoothness of the trend line of the monitoring parameters of the repeated use product and the size of the balance residual, controlling the balance between the estimated trend and signal redundancy. For x, since the weighted objective function is a convex function, the minimum value Is unique, then The curve after the repeated use of product monitoring data through trend filtering and its advantages over traditional conventional alarm methods are shown in the attached figure. Figure 2 False alarms are reduced and more accurate guidance is provided for determining when to perform preventive maintenance.

[0054] Step 42, set the preventive maintenance method criteria for the reused product. Determine the conventional alarm threshold line, that is, the potential failure threshold L p It is a maintenance decision variable used to determine the maintenance timing of reusable products. Figure 3 The functional failure threshold of the reused product is L, which is a fixed parameter, then 0<L p <L. The preventive maintenance method for reusable products is set as follows: When the product monitoring parameter X (t) Less than the potential failure threshold L p When the monitoring parameter X (t) Exceeding the potential failure threshold L p When k p 1 >k p 2 When k p1 ≤k p 2 Perform preventive maintenance on the product when necessary.

[0055] With the extensive application of current fault prediction and health management technologies, the method of setting product early failure threshold lines by monitoring product operation data through sensors and judging whether the product needs preventive maintenance based on data-driven methods has been widely used.

[0056] The embodiment of the present application also provides an electronic device, Figure 4 The structure of the electronic device provided by the embodiment of the present invention is shown. For example, the electronic device 40 may include a processor 41, a memory 42 and a transmission device 43. The processor 41 is used to execute the reuse product maintenance strategy optimization method mentioned in the above embodiment, wherein the processor and the memory may be connected by a bus or other means, taking the bus connection as an example. The transmission device may be connected to the processor and the memory by wire or wirelessly. The memory, as a non-transient computer-readable storage medium, may be used to store non-transient software programs, non-transient computer executable programs and modules, such as program instructions / modules corresponding to the reuse product maintenance strategy optimization method in the embodiment of the present application. The processor executes various functional applications and data processing of the processor by running the non-transient software programs, instructions and modules stored in the memory, that is, the reuse product maintenance strategy optimization method in the above method embodiment is implemented. The memory may include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application required by at least one function; the storage data area may store data created by the processor, etc. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a memory remotely arranged relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof. The one or more modules are stored in the memory, and when executed by the processor, the method for optimizing the maintenance strategy of the reused product in the embodiment is executed.

[0057] As another aspect, the present application also provides a computer-readable storage medium, which may be the computer-readable storage medium included in the device described in the above embodiment; or it may be a computer-readable storage medium that exists independently and is not assembled into the device. The computer-readable storage medium may be a tangible storage medium, such as a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a floppy disk, a hard disk, a removable storage disk, a CD-ROM, or any other form of storage medium known in the technical field. The computer-readable storage medium stores one or more programs, and the programs are used by one or more processors to execute the method for optimizing the maintenance strategy of reusable products described in the present application.

[0058] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for optimizing maintenance strategy for reusable products, characterized in that: Construct a failure rate function for reusable products to describe the change in failure rate after multiple uses. Define a cost-effectiveness formula using the ratio of preventive maintenance cost to failure rate change for reusable products. Use the cost-effectiveness ratio to determine the choice of preventive maintenance method for reusable products.

2. The method according to claim 1, characterized in that It also includes optimizing the fluctuation curve of monitoring parameters of reusable products through trend filtering, clarifying the timing and means of preventive maintenance of reusable products, and optimizing the maintenance strategy of reusable products.

3. The method according to claim 2, characterized in that The failure rate function for building a reusable product is: λ i+1 (t)=m i λ i (t+n i T i ),0<t<T i+1 Where, T i is the time interval between the ith preventive maintenance and the last maintenance, n i is the service age factor; m i is the failure rate increasing factor, n i and m i The value of is derived from the summary of the product's historical maintenance and guarantee data.

4. The method according to any one of claims 1 to 3, characterized in that: The preventive maintenance cost calculation of the reused product is achieved through the following steps: Step 21, define the cost of product preventive maintenance: use and Represents the average cost of one preventive maintenance and one preventive replacement respectively. If a reusable product is subjected to N preventive maintenance operations: Step 22, define the loss when the product is down: When the reused product is in downtime, the downtime M caused by the preventive maintenance of the reused product t for: Where Cs is the downtime cost rate per unit time of the reused product; and Respectively represent the average time for a preventive maintenance and a preventive replacement of the product; Step 23, define the total cost of reusing products for preventive maintenance as:

5. The method according to claim 4, characterized in that Select the preventive maintenance method for reusable products based on the cost-effectiveness ratio; the cost-effectiveness ratio of reusable products after preventive maintenance can be expressed as: In the formula, when k p 1 >k p 2 When k p 1 ≤k p 2 Perform preventive maintenance on the product when necessary.

6. The method according to claim 2 or 3, characterized in that: The specific implementation steps of optimizing the parameter fluctuation curve of repeated use product monitoring through trend filtering are as follows: Step 41, assuming that the standard time series yj (j = 1, ..., n) is composed of the basic trend x j and the random variable z j Composition; l1 trend filtering is achieved by minimizing the weighted objective function, where the weighted objective function is: When the weighted objective function takes the minimum value, the basic trend of the monitoring data of reused products can be estimated; Step 42, set the preventive maintenance method criteria for reusable products: determine the conventional alarm threshold line, that is, the potential failure threshold L p is a maintenance decision variable used to determine the maintenance timing of reused products. The functional failure threshold of reused products is L, which is a fixed parameter. Then 0<L p <L; The preventive maintenance method for reusable products is set as follows: (t) Less than the potential failure threshold L p When the monitoring parameter X (t) Exceeding the potential failure threshold L p When k p 1 >k p 2 When k p 1 ≤k p 2 Perform preventive maintenance on the product when necessary.

7. An electronic device, characterized in that: The electronic device includes a processor and a memory for storing executable instructions of the processor; the processor is used to read the executable instructions from the memory and execute the instructions to implement the method for optimizing the maintenance strategy of reusable products as described in any one of claims 1-6 above.

8. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and the computer program is used to execute the method for optimizing the maintenance strategy of reusable products as described in any one of claims 1 to 6.

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