A two-dimensional warranty product preventive maintenance strategy making method considering usage rate difference

Abstract

The application discloses a two-dimensional warranty product preventive maintenance strategy making method considering usage rate difference, belongs to the technical field of two-dimensional warranty product preventive maintenance, and aims at accurately evaluating warranty cost and effectively implementing preventive maintenance. The method comprises the following steps: S1, constructing a usage rate probability distribution and determining actual warranty periods under different usage rates based on user product usage data; S2, determining a failure rate type of the product based on failure mechanisms and historical failure conditions of the product or similar products; S3, determining a failure rate function of the product based on warranty data of the product or similar products; S4, constructing a preventive maintenance strategy of the product within a two-dimensional warranty period according to the failure rate type and the warranty period; S5, establishing a total warranty cost model according to the probability distribution model and the preventive maintenance strategy; and S6, taking the minimum total warranty cost as a target to determine an optimal preventive maintenance strategy. The application can effectively reduce the failure times of products and reduce warranty cost.

Description

Technical Field

[0001] This invention relates to the field of preventive maintenance technology for two-dimensional warranty products, and more specifically to a method for formulating a preventive maintenance strategy for two-dimensional warranty products that takes into account differences in usage rates. Background Technology

[0002] A two-dimensional warranty uses a two-dimensional plane composed of time and usage as the product quality guarantee period. For example, the two-dimensional warranty period for automobiles is generally 3 years or 100,000 kilometers. Repair costs for malfunctions occurring within the two-dimensional warranty period are borne by the company. Designing a scientifically sound and reasonable preventative maintenance strategy can reduce the total warranty cost of the product within the two-dimensional warranty period.

[0003] Currently, preventive maintenance strategies are mainly divided into periodic maintenance, condition-based maintenance, and proactive maintenance. Periodic maintenance is usually based on time and involves preventive maintenance on all equipment. It is labor-intensive and prone to over-maintenance or under-maintenance. Condition-based maintenance involves using condition monitoring technologies to carry out personalized preventive maintenance, but it has high requirements for data acquisition systems and is not suitable for systems without monitoring data. Proactive maintenance requires a deep understanding of complex fault mechanisms, making it difficult to implement and less feasible.

[0004] For two-dimensional warranty products with a large number of units and significant differences in usage rates, the actual warranty period is affected by the usage rate. Users with high usage rates have shorter warranty periods, while users with low usage rates have less usage. Therefore, warranty costs are greatly influenced by usage rates. Preventive maintenance strategies that do not consider usage rate differences cannot accurately assess warranty costs and are difficult to implement effectively. Summary of the Invention

[0005] The purpose of this invention is to provide a method for formulating a preventive maintenance strategy for two-dimensional warranty products that takes into account differences in usage rates, so as to effectively reduce the number of product failures and reduce warranty costs.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0007] This invention provides a method for formulating a preventive maintenance strategy for two-dimensional warranty products that takes into account usage rate differences. The method includes:

[0008] S1: Based on user data on product usage, construct a probability distribution of usage rate and determine the actual warranty period under different usage rates;

[0009] S2: Determine the failure rate type of the product based on the failure mechanism and historical failure data of the product or similar products;

[0010] S3: Determine the failure rate function based on the quality assurance data and failure rate type of the product or similar products;

[0011] S4: Based on the failure rate function and the actual warranty period, construct a preventive maintenance strategy for the product within the two-dimensional warranty period;

[0012] S5: Based on the probability distribution of the usage rate, the failure rate model, and the preventive maintenance strategy, establish a total warranty cost model;

[0013] S6: Determine the optimal preventive maintenance strategy with the goal of minimizing total warranty costs.

[0014] Alternatively, in step S1, the actual warranty period under different usage rates is determined in the following way:

[0015] If r ≤ r0, the actual warranty period of the product is [T, Tr]; if r > r0, the actual warranty period of the product is [T, Tr].

[0016] Where r represents the usage rate, r0 is the standard usage rate, T represents the warranty period, and S represents the usage amount under warranty.

[0017] Alternatively, in S2, the product failure rate type includes:

[0018] Failure rate affected only by time;

[0019] Failure rate affected only by usage; and

[0020] The failure rate is also affected by time and usage.

[0021] Alternatively, in S4, the preventative maintenance strategy includes:

[0022] When only affected by time, the usage rate is [0, r] p The product in T p Preventive maintenance should be performed regularly; at this time, r p >r0,

[0023] When only affected by usage, the usage rate is [r] p ,∞] products in S p Preventative maintenance is performed based on usage, at which point S p ≤Tr p r p ≤r0;

[0024] When simultaneously affected by time and usage, the usage rate is within the range [r] min ,r max The product in T p Preventative maintenance should be performed regularly.

[0025] Where, r p This represents the critical utilization rate for preventive maintenance, where r0 is the standard utilization rate and S represents the usage amount covered by the warranty, and T represents the warranty period. p S represents preventative maintenance time, where s represents actual usage. p Indicates the amount of preventative maintenance used, r min r represents the minimum utilization rate at which preventative maintenance is required. max This indicates the maximum utilization rate at which preventative maintenance is performed, and k represents the timing of maintenance.

[0026] Alternatively, in step S5, the total warranty cost model is:

[0027] S2=(N 21 +N 22 C1+N 23 C2

[0028] Where S2 is the total warranty cost, N 21 N represents the potential average number of failures during the two-dimensional warranty period for users who do not perform preventative maintenance. 22 N represents the potential average number of failures for users who perform preventative maintenance during the two-dimensional warranty period. 23 The average number of preventive maintenance operations is given. C1 represents the cost of a single post-maintenance repair, and C2 represents the cost of a single preventive maintenance operation.

[0029] Alternatively, when only time is affected, the calculation formulas for each parameter in the total warranty cost model are as follows:

[0030]

[0031]

[0032]

[0033] Where, N 21 r represents the potential average number of failures during the two-dimensional warranty period for users who do not perform preventative maintenance. p Let f(r) represent the critical utilization rate for preventive maintenance, f(r) represent the utilization rate probability density function, s represent the actual utilization, r represent the utilization rate, λ(t) represent the failure rate function over time before preventive maintenance is applied, t represent the actual utilization time, and N represent the failure rate. 22 For users who perform preventative maintenance, the potential average number of failures during the two-dimensional warranty period is given by r0, which represents the standard utilization rate. S represents the warranty usage amount, and T represents the warranty period. p Let λ'(t) represent the preventive maintenance time, and let λ'(t) represent the failure rate function over time after the application of preventive maintenance. α represents maintenance intensity and N 23 This represents the average number of preventative maintenance procedures.

[0034] Alternatively, when only the usage volume is affected, the calculation formulas for each parameter in the total warranty cost model are as follows:

[0035]

[0036]

[0037]

[0038] Where, N 21 r represents the potential average number of failures during the two-dimensional warranty period for users who do not perform preventative maintenance. p Let f(r) represent the critical utilization rate for preventive maintenance, f(r) represent the utilization rate probability density function, s represent the actual utilization, r represent the utilization rate, λ(s) represent the failure rate function as a function of utilization before preventive maintenance, t represent the actual utilization time, and N represent the failure rate. 22 For users who perform preventative maintenance, the potential average number of failures during the two-dimensional warranty period is given by r0, which represents the standard utilization rate. S represents the warranty usage amount, and T represents the warranty period. p N represents the amount of preventative maintenance used, λ'(s) represents the failure rate function over time after preventative maintenance is performed, and N represents the failure rate function over time. 23 This represents the average number of preventative maintenance procedures.

[0039] Alternatively, when both time and usage are affected, the calculation formulas for each parameter in the total warranty cost model are as follows:

[0040]

[0041]

[0042]

[0043] Where, N 21 r represents the potential average number of failures during the two-dimensional warranty period for users who do not perform preventative maintenance. min Let f(r) represent the minimum utilization rate at which preventative maintenance is required, T represent the warranty period, f(r) represent the utilization rate probability density function, λ(r,t) represent the failure rate function as a function of time and usage before preventative maintenance is applied, r represent the utilization rate, and t represent the actual usage time. max T represents the maximum utilization rate at which preventative maintenance is performed. p N represents preventative maintenance time, s represents actual usage, and N represents the amount of time spent on maintenance. 22For users who perform preventative maintenance, the potential average number of failures during the two-dimensional warranty period is given by r0, which represents the standard utilization rate. S represents the warranty usage, λ'(r,t) represents the failure rate function as a function of time and usage after preventive maintenance, and N 23 This represents the average number of preventative maintenance procedures.

[0044] Alternatively, the product may be an automobile.

[0045] The present invention has the following beneficial effects:

[0046] This invention takes into account the different failure patterns caused by different user usage rates and product operating conditions. Based on this, it can select some high-risk users who need to be subject to preventive maintenance and perform preventive maintenance at appropriate times, thereby reducing the overall number of failures and reducing warranty costs. Attached Figure Description

[0047] Figure 1 This is a flowchart illustrating the method for developing a preventative maintenance strategy for two-dimensional quality assurance products that takes into account usage differences, as described in this invention. Detailed Implementation

[0048] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0049] Example 1

[0050] This invention provides a method for developing a preventative maintenance strategy for two-dimensional warranty products that takes into account differences in usage rates, with reference to... Figure 1 As shown, the method for developing a two-dimensional quality assurance product preventive maintenance strategy that considers usage rate differences includes:

[0051] S1: Based on user data on product usage, construct a probability distribution of usage rate and determine the actual warranty period under different usage rates;

[0052] The product of this invention can be any product with two-dimensional warranty, and this invention does not impose any specific limitations.

[0053] Furthermore, this invention determines the actual warranty period for products with low usage rates through the following methods:

[0054] If r ≤ r0, the actual warranty period of the product is [T, Tr]; if r > r0, the actual warranty period of the product is [T, Tr].

[0055] Where r represents the usage rate, r0 is the standard usage rate, T represents the warranty period, and S represents the usage amount under warranty.

[0056] S2: Determine the failure rate type of the product based on the failure mechanism and historical failure data of the product or similar products;

[0057] Product failure rate types include:

[0058] Failure rate affected only by time;

[0059] Failure rate affected only by usage; and

[0060] The failure rate is also affected by time and usage.

[0061] S3: Determine the failure rate function based on the quality assurance data and failure rate type of the product or similar products;

[0062] Here, the failure rate function can be retrieved using existing software based on the failure rate type, or it can be determined manually.

[0063] S4: Based on the failure rate function and the actual warranty period, construct a preventative maintenance strategy for the product within the two-dimensional warranty period; when only affected by time, for usage rates [0, r]... p The product in T p Preventive maintenance should be performed regularly; at this time, r p >r0,

[0064] When only affected by usage, the usage rate is [r] p ,∞] products in S p Preventative maintenance is performed based on usage, at which point S p ≤Tr p r p ≤r0;

[0065] When simultaneously affected by time and usage, the usage rate is within the range [r] min ,r max The product in T p Preventative maintenance should be performed regularly.

[0066] Where, r p This represents the critical utilization rate for preventive maintenance, where r0 is the standard utilization rate and S represents the usage amount covered by the warranty, and T represents the warranty period. p S represents preventative maintenance time, where s represents actual usage. p Indicates the amount of preventative maintenance used, r min r represents the minimum utilization rate at which preventative maintenance is required. max This indicates the maximum utilization rate at which preventative maintenance is performed, and k represents the timing of maintenance.

[0067] S5: Based on the probability distribution of the usage rate, the failure rate model, and the preventive maintenance strategy, establish a total warranty cost model;

[0068] The total warranty cost model is as follows:

[0069] S2=(N 21 +N 22 C1+N 23 C2

[0070] Where S2 is the total warranty cost, N 21 N represents the potential average number of failures during the two-dimensional warranty period for users who do not perform preventative maintenance. 22 N represents the potential average number of failures for users who perform preventative maintenance during the two-dimensional warranty period. 23 The average number of preventive maintenance operations is given. C1 represents the cost of a single post-maintenance repair, and C2 represents the cost of a single preventive maintenance operation.

[0071] When only time is a factor, the calculation formulas for each parameter in the total warranty cost model are as follows:

[0072]

[0073]

[0074]

[0075] Where, N 21 r represents the potential average number of failures during the two-dimensional warranty period for users who do not perform preventative maintenance. p Let f(r) represent the critical utilization rate for preventive maintenance, f(r) represent the utilization rate probability density function, s represent the actual utilization, r represent the utilization rate, λ(t) represent the failure rate function over time before preventive maintenance is applied, t represent the actual utilization time, and N represent the failure rate. 22 For users who perform preventative maintenance, the potential average number of failures during the two-dimensional warranty period is given by r0, which represents the standard utilization rate. S represents the warranty usage amount, and T represents the warranty period. p Let λ'(t) represent the preventive maintenance time, and let λ'(t) represent the failure rate function over time after the application of preventive maintenance. In practice, it's not limited to this function. When T > Tp, it can be written as: λ(t, α, Tp), where α represents the maintenance intensity and N 23 This represents the average number of preventative maintenance procedures.

[0076] Alternatively, when only the usage volume is affected, the calculation formulas for each parameter in the total warranty cost model are as follows:

[0077]

[0078]

[0079]

[0080] Where, N 21 r represents the potential average number of failures during the two-dimensional warranty period for users who do not perform preventative maintenance. p Let f(r) represent the critical utilization rate for preventive maintenance, f(r) represent the utilization rate probability density function, s represent the actual utilization, r represent the utilization rate, λ(s) represent the failure rate function as a function of utilization before preventive maintenance, t represent the actual utilization time, and N represent the failure rate. 22 For users who perform preventative maintenance, the potential average number of failures during the two-dimensional warranty period is given by r0, which represents the standard utilization rate. S represents the warranty usage amount, and T represents the warranty period. p N represents the amount of preventative maintenance used, λ'(s) represents the failure rate function over time after preventative maintenance is performed, and N represents the failure rate function over time. 23 This represents the average number of preventative maintenance procedures.

[0081] Alternatively, when both time and usage are affected, the calculation formulas for each parameter in the total warranty cost model are as follows:

[0082]

[0083]

[0084]

[0085] Where, N 21 r represents the potential average number of failures during the two-dimensional warranty period for users who do not perform preventative maintenance. min Let f(r) represent the minimum utilization rate at which preventative maintenance is required, T represent the warranty period, f(r) represent the utilization rate probability density function, λ(r,t) represent the failure rate function as a function of time and usage before preventative maintenance is applied, r represent the utilization rate, and t represent the actual usage time. max T represents the maximum utilization rate at which preventative maintenance is performed. p N represents preventative maintenance time, s represents actual usage, and N represents the amount of time spent on maintenance. 22 For users who perform preventative maintenance, the potential average number of failures during the two-dimensional warranty period is given by r0, which represents the standard utilization rate. S represents the warranty usage, λ'(r,t) represents the failure rate function as a function of time and usage after preventive maintenance, and N 23 This represents the average number of preventative maintenance procedures.

[0086] S6: Determine the optimal preventive maintenance strategy with the goal of minimizing total warranty costs.

[0087] Here, a common enumeration method can be used, given the parameters of various preventive maintenance strategies, to calculate the warranty cost and select the parameters corresponding to the optimal solution; alternatively, an optimization algorithm, such as a genetic optimization algorithm, can be used to obtain the lowest total warranty cost, thereby determining the optimal preventive maintenance strategy.

[0088] Example 2

[0089] This invention provides a method for developing a preventative maintenance strategy for two-dimensional warranty products that takes into account differences in usage rates, with reference to... Figure 1 As shown, the method for developing a two-dimensional quality assurance product preventive maintenance strategy that considers usage rate differences includes:

[0090] S1: Based on user data on product usage, construct a probability distribution of usage rate and determine the actual warranty period under different usage rates;

[0091] The product described in this invention is a product with a two-dimensional warranty. As a specific embodiment, the following detailed description focuses on the product as an automobile:

[0092] The two-dimensional warranty period for automotive products includes two dimensions: mileage limit s and usage time limit t. The usage rate of automotive products is the ratio of mileage to driving time. When driving time is measured in months, the usage rate is the average monthly mileage r of the vehicle.

[0093] The average monthly mileage r of automobiles is widely considered to follow a log-normal distribution, denoted as lnr ~ N(μ,σ). 2 ), where μ and σ are distribution parameters, and their probability density functions are:

[0094]

[0095] Where μ and σ 2 Let μ and σ be the mean and variance of the logarithm of monthly mileage, respectively, and μ and σ be the mean and variance of the logarithm of monthly mileage, respectively. 2 The value is obtained by using the method of moments to estimate the actual monthly average mileage of the vehicle. The calculation formula is:

[0096]

[0097]

[0098] in: This represents the sample mean of the actual monthly average mileage driven by vehicles. This represents the sample variance of the actual monthly average mileage driven by the vehicles.

[0099] In addition, the actual warranty period corresponding to the unused rate r is determined in the following way:

[0100] If r ≤ r0, the actual warranty period of the product is [T, Tr]; if r > r0, the actual warranty period of the product is [T, Tr].

[0101] Where r represents the usage rate, r0 is the standard usage rate, T represents the warranty period, and S represents the warranty mileage.

[0102] S2: Determine the failure rate type of the product based on the failure mechanism and historical failure data of the product or similar products;

[0103] Based on the research on automobile failure rate types in this invention, the failure rate types of automobiles include:

[0104] Failure rate affected only by time;

[0105] Failure rate affected only by mileage; and

[0106] The failure rate is also affected by time and mileage.

[0107] S3: Determine the failure rate function based on the quality assurance data and failure rate type of the product or similar products;

[0108] Based on this, the preventive maintenance strategy for the two-dimensional warranty period constructed by this invention includes:

[0109] When only affected by time, the usage rate is [0, r] p The product in T p Preventive maintenance should be performed regularly; at this time, r p >r0,

[0110] That is, if it is only affected by the time t, then it is a function of the specified time t, denoted as λ(t).

[0111] Since product failure rate is only related to time, customers with usage rates r > r0 have shorter warranty periods T compared to other customers, thus having fewer potential failures. Furthermore, the higher the usage rate, the shorter the warranty expiration date, and the fewer potential failures. Therefore, the preventative maintenance strategy in this case is to target customers with usage rates [0, r]. p The product in T p Preventive maintenance should be performed regularly, including r p >r0,

[0112] When only affected by mileage, the usage rate is [r] p ,∞] products in S p During preventative maintenance, S...p ≤Tr p , r p ≤r0.

[0113] That is, since the product failure rate is only related to mileage, customers whose usage rate r<r0 have a shorter warranty mileage S than other customers, so the potential number of failures is fewer, and the smaller the usage rate, the shorter the corresponding mileage when the warranty expires, and the fewer potential failures. Therefore, the optimal preventive maintenance strategy should be applied to products with usage rate in [r p , ∞] for preventive maintenance at S p mileage, where S p ≤Tr p , r p ≤r0.

[0114] When the failure is affected by both time and usage mileage, preventive maintenance is performed at time T for products whose usage rate is in the interval [r min , r max , where T p is the time for preventive maintenance, at this time, k∈[0, 1].

[0115] Since the product failure rate is related to both driving time t and driving mileage s, when the usage rate r<r0, the time for the product to reach the warranty period is all T. The smaller the usage rate, the shorter the corresponding mileage when reaching the warranty period, and the smaller the potential failure probability. When the usage rate r>r0, the mileage for the product to reach the warranty period is all S. The larger the usage rate, the shorter the corresponding time when reaching the warranty period, and the smaller the potential failure probability. Therefore, the optimal preventive maintenance strategy should be applied to products whose usage rate is in the interval [r min , r max , preventive maintenance is performed at time T, where, p T is the time for preventive maintenance, wherein, k∈[0, 1].

[0116] wherein, r p represents the critical usage rate for preventive maintenance, r0 is the standard usage rate and S represents warranty mileage, T represents warranty time, T p represents preventive maintenance time, s represents driving mileage, S p represents preventive maintenance mileage, r min represents the minimum usage rate for adopting preventive maintenance, r max represents the maximum usage rate for adopting preventive maintenance, and k represents maintenance timing.

[0117] S4: Establish a total warranty cost model according to the probability distribution model and the preventive maintenance strategy;

[0118] The total warranty cost is divided into two parts: post-repair repair cost and preventive maintenance cost. Let C1 and C2 be the cost of a single post-repair repair and the cost of a single preventive maintenance, respectively.

[0119] The decision variables for strategy optimization are the usage period during which preventative maintenance is performed and the maintenance time T. p or S p The three failure modes—product failure rate depending only on time, product failure rate depending only on mileage, and product failure rate depending on both time and mileage—correspond to the intervals [0, r], respectively. p ]、[r p ,∞]、[r min ,r max ];

[0120] Therefore, the total warranty cost model is as follows:

[0121] S2=(N 21 +N 22 C1+N 23 C2

[0122] Where S2 is the total warranty cost, N 21 N represents the potential average number of failures during the two-dimensional warranty period for users who do not perform preventative maintenance. 22 N represents the potential average number of failures for users who perform preventative maintenance during the two-dimensional warranty period. 23 The average number of preventive maintenance operations is given. C1 represents the cost of a single post-maintenance repair, and C2 represents the cost of a single preventive maintenance operation.

[0123] When only time is a factor, the calculation formulas for each parameter in the total warranty cost model are as follows:

[0124]

[0125]

[0126]

[0127] Where, N 21 r represents the potential average number of failures during the two-dimensional warranty period for users who do not perform preventative maintenance. p Let f(r) represent the critical service life for preventive maintenance, f(r) represent the probability density function of service life, s represent mileage, r represent service life, λ(t) represent the failure rate function over time before preventive maintenance is applied, t represent mileage, and N represent service life. 22 For users who perform preventative maintenance, the potential average number of failures during the two-dimensional warranty period is given by r0, which represents the standard utilization rate. S represents the warranty mileage, and T represents the warranty period. pLet λ'(t) represent the preventive maintenance time, and let λ'(t) represent the failure rate function over time after the application of preventive maintenance. α represents maintenance intensity and N 23 This represents the average number of preventative maintenance procedures.

[0128] When only mileage is affected, the calculation formulas for each parameter in the total warranty cost model are as follows:

[0129]

[0130]

[0131]

[0132] Where, N 21 r represents the potential average number of failures during the two-dimensional warranty period for users who do not perform preventative maintenance. p Let f(r) represent the critical utilization rate for preventive maintenance, f(r) represent the utilization rate probability density function, s represent mileage, r represent the utilization rate, λ(s) represent the failure rate function as a function of mileage before preventive maintenance is applied, t represent the driving time, and N represent the utilization rate. 22 For users who perform preventative maintenance, the potential average number of failures during the two-dimensional warranty period is given by r0, which represents the standard utilization rate. S represents the warranty mileage, and T represents the warranty period. p Let N represent the preventive maintenance mileage, λ'(s) represent the failure rate function over time after the application of preventive maintenance, and N represent the failure rate function over time. 23 This represents the average number of preventative maintenance procedures.

[0133] When both time and mileage are affected, the calculation formulas for each parameter in the total warranty cost model are as follows:

[0134]

[0135]

[0136]

[0137] Where, N 21 r represents the potential average number of failures during the two-dimensional warranty period for users who do not perform preventative maintenance. min Let f(r) represent the minimum utilization rate at which preventative maintenance is required, T represent the warranty period, f(r) represent the utilization rate probability density function, and λ(r,t) represent the failure rate function as a function of time and mileage before preventative maintenance is applied. Here, r represents the utilization rate, and t represents the driving time. max T represents the maximum utilization rate at which preventative maintenance is performed. p Indicates preventative maintenance time, s represents mileage, N22 For users who perform preventative maintenance, the potential average number of failures during the two-dimensional warranty period is given by r0, which represents the standard utilization rate. S represents the warranty mileage, λ'(r,t) represents the failure rate function as a function of time and mileage after preventive maintenance, and N 23 This represents the average number of preventative maintenance procedures.

[0138] When preventative maintenance strategies are clearly uneconomical, this invention also proposes a formula for calculating the total warranty cost, namely: before adopting the preventative maintenance strategy of this invention, the formula for the total warranty cost of a two-dimensional warranty product is:

[0139] S1=N1C1

[0140] Where N1 represents the number of failures and C1 represents the cost of a single subsequent repair.

[0141] When only affected by time,

[0142] When only affected by mileage,

[0143] When affected by both time and mileage

[0144] S5: Determine the optimal preventative maintenance strategy with the goal of minimizing total warranty costs.

[0145] Here, a common enumeration method can be used, given multiple sets of preventive maintenance strategy parameters, to calculate the total warranty cost and select the optimal solution; alternatively, an optimization algorithm, such as a genetic optimization algorithm, can be used to obtain the lowest total warranty cost, thereby determining the optimal preventive maintenance strategy.

[0146] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for developing a preventative maintenance strategy for two-dimensional quality assurance products that considers usage rate differences, characterized in that, The method for developing a two-dimensional quality assurance product preventative maintenance strategy that takes into account usage differences includes: S1: Based on user data on product usage, construct a probability distribution of usage rate and determine the actual warranty period under different usage rates; S2: Determine the failure rate type of the product based on the failure mechanism and historical failure data of the product or similar products; S3: Determine the failure rate function based on the quality assurance data and failure rate type of the product or similar products; S4: Based on the failure rate function and the actual warranty period, construct a preventive maintenance strategy for the product within the two-dimensional warranty period; S5: Based on the probability distribution of the usage rate, the failure rate model, and the preventive maintenance strategy, establish a total warranty cost model; S6: Determine the optimal preventive maintenance strategy with the goal of minimizing total warranty costs; In S5, the total warranty cost model is as follows: in, For total warranty costs, The potential average number of failures during the two-dimensional warranty period for users who do not perform preventative maintenance. The potential average number of failures during the two-dimensional warranty period for users who perform preventative maintenance. This represents the average number of preventative maintenance operations. This indicates the cost of a single subsequent repair. This indicates the cost of a single preventative maintenance procedure. When only time is a factor, the calculation formulas for each parameter in the total warranty cost model are as follows: in, This indicates the critical service life for preventative maintenance. This represents the probability density function of usage rate. s Indicates actual usage. r Indicates usage rate, This represents the failure rate function that changes over time before preventative maintenance is applied. t Indicates the actual usage time. For standard usage rate and , S Indicates the amount used under warranty. T Indicates the warranty period. Indicates the time for preventative maintenance. This represents the failure rate function that changes over time after preventative maintenance is performed, and , Indicates maintenance intensity and ; When only the usage volume is affected, the calculation formulas for each parameter in the total warranty cost model are as follows: in, This represents the failure rate function as a function of usage before preventative maintenance is applied. Indicates the amount of preventative maintenance used. This function represents the failure rate as a function of usage after preventative maintenance has been performed. When both time and usage volume are affected, the calculation formulas for each parameter in the total warranty cost model are as follows: in, This indicates the minimum utilization rate at which preventative maintenance is required. This represents the failure rate function, which varies with time and usage rate before preventative maintenance is applied. This indicates the maximum utilization rate at which preventative maintenance is performed. This represents the failure rate function, which changes over time and with usage rate after preventative maintenance has been performed.

2. The method for formulating a preventive maintenance strategy for two-dimensional quality assurance products considering usage rate differences according to claim 1, characterized in that, In step S1, the actual warranty period under different usage rates is determined in the following way: like The actual warranty period of the product is then... ;like At this time, the actual warranty period of the product is .

3. The method for formulating a preventive maintenance strategy for two-dimensional quality assurance products considering usage rate differences according to claim 1, characterized in that, In S2, the failure rate types of the product include: Failure rate affected only by time; Failure rate affected only by usage; and The failure rate is also affected by time and usage.

4. The method for formulating a preventive maintenance strategy for two-dimensional quality assurance products considering usage rate differences according to claim 3, characterized in that, In S4, the preventative maintenance strategy includes: When only affected by time, the utilization rate Products in Preventative maintenance should be performed regularly. , ; When only the amount of usage is affected, the utilization rate Products in Preventative maintenance is performed based on usage volume. , ; When simultaneously affected by time and usage volume, the usage rate is within a certain range. Products in Preventative maintenance should be performed regularly. , ; in, k Indicates when maintenance is needed.

5. The method for formulating a two-dimensional quality assurance product preventive maintenance strategy considering usage rate differences according to any one of claims 1-4, characterized in that, The product in question is a car.

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