Maintenance management device, maintenance management method, and maintenance management program

Abstract

To propose a maintenance management system, a maintenance management method, and a maintenance management program capable of reducing a loss in a manufacturing process.SOLUTION: A maintenance management system 50 includes: a control unit 51 that determines maintenance information on a processing apparatus 10 which manufactures processed products; and an output unit 53 that outputs the maintenance information determined by the control unit 51. The control unit 51 determines the maintenance information on the basis of a maintenance cost required for maintenance of the processing apparatus and a failure cost attributable to the processing apparatus 10. The failure cost encompasses an opportunity loss derived from the fact that the processing apparatus has failed and stopped.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a maintenance management device, a maintenance management method, and a maintenance management program. [Background technology]

[0002] Conventionally, a method for updating the scheduled maintenance timing of equipment using a loss function defined for the equipment is known. In the method described in Patent Document 1, a loss function is determined that takes into account the loss when the equipment breaks down. In addition, the scheduled maintenance timing is changed based on the loss function so as to reduce the loss.

[0003] Furthermore, Patent Document 2 describes a method for evaluating a maintenance method by calculating the amount of damage when a failure occurs and the probability of overlooking a failure symptom for each part, and estimating the risk for each part based on the failure rate, the amount of damage when a failure occurs, and the probability of overlooking a failure symptom. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2004-145496 A [Patent Document 2] JP 2004-152017 A Summary of the Invention [Problem to be solved by the invention]

[0005] The processing equipment used in the manufacturing process of products is maintained in order to reduce losses in the manufacturing process as much as possible. It is required to rationally manage the maintenance of processing equipment so that losses in the manufacturing process can be reduced as much as possible.

[0006] Therefore, an object of the present disclosure is to propose a maintenance management device, a maintenance management method, and a maintenance management program that can rationally reduce losses in the manufacturing process. [Means for solving the problem]

[0007] One embodiment of the present disclosure that solves the above problem is as follows. [1] A control unit that determines maintenance information for a processing device that manufactures a processed product; an output unit that outputs the security information determined by the control unit; Equipped with The control unit determines the maintenance information based on a maintenance cost required for maintaining the processing device and a failure cost caused by the processing device; A maintenance management device, wherein the failure cost includes opportunity loss caused by the processing device being stopped due to failure. [2] The control unit of the maintenance management device described in [1] uses a post-maintenance operation time corresponding to the time the processing equipment is operated after maintenance of the processing equipment as an argument, generates a loss function represented by the sum of a first term proportional to the product of the inverse of the post-maintenance operation time and the maintenance cost, and a second term proportional to the product of the post-maintenance operation time and the failure cost, and determines the maintenance information based on the loss function. [3] The control unit of the maintenance management device described in [2] calculates, as the maintenance information, the post-maintenance operating time when the value of the loss function becomes a minimum value or is within a predetermined range of the minimum value. [4] The maintenance management device according to [2] or [3], wherein the control unit generates the loss function in a format including the failure cost in the second term of the loss function, which is a value obtained by multiplying the opportunity loss by a coefficient based on the operating status of the processing equipment. [5] The maintenance management device described in any one of [2] to [4], wherein the control unit generates the loss function in a form in which the failure cost in the second term of the loss function is multiplied by a coefficient based on a characteristic factor of the processing equipment. [6] A step in which a maintenance management device determines maintenance information for a processing device that manufactures a processed product based on a maintenance cost required for maintaining the processing device and a failure cost caused by the processing device, and a step in which the maintenance management device outputs the determined maintenance information, A maintenance management method, wherein the failure cost includes an opportunity loss caused by the processing device being stopped due to a failure. [7] A step of causing a processor to determine maintenance information of a processing device that manufactures a processed product based on a maintenance cost required for maintaining the processing device and a failure cost caused by the processing device, and a step of outputting the determined maintenance information. Run the command, A maintenance management program in which the failure cost includes opportunity loss caused by the processing equipment being stopped due to a failure. Effect of the Invention

[0008] According to an embodiment of the present disclosure, losses in the manufacturing process may be reduced. [Brief description of the drawings]

[0009] [Figure 1] 1 is a block diagram showing an example of the configuration of a maintenance management system according to an embodiment; [Diagram 2] FIG. 2 is a diagram showing a configuration example of a wire saw device as a processing device. [Diagram 3] 2A and 2B are a plan view and a side view showing an example of the configuration of a guide roller of a wire saw device. [Figure 4] FIG. 13 is a diagram illustrating an example of a graph of a loss function generated by a maintenance management device according to an embodiment. [Diagram 5] FIG. 13 is a diagram illustrating an example of a graph of a loss function for explaining a maintenance cost when an actual availability rate is lower than an assumed availability rate. [Figure 6] 1 is a flowchart showing an example of a procedure of a maintenance management method according to an embodiment. [Figure 7] FIG. 13 is a diagram illustrating an example of a graph of a loss function when the mean time between failures of a processing device is taken into consideration. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (Overview of the maintenance management system 1 according to one embodiment) A maintenance management system 1 (see FIG. 1) or a maintenance management device 50 (see FIG. 1) according to an embodiment of the present disclosure manages the maintenance of a processing device 10 (see FIG. 1 or FIG. 2) installed in a factory or the like that manufactures products. The processing device 10 processes received materials in at least some of the processes for manufacturing the product, and delivers them as a processed product.

[0011] The processing device 10 may break down and stop during processing. In this case, the processed product that was being processed may be discharged as a defective product. Even if the processing device 10 does not stop, the processed product may be discharged as a defective product. A breakdown in the processing device 10 and the discharge of a defective product cause losses in a manner that is easily manifested in the processing device 10. A fault that causes losses in a manner that is easily manifested in the processing device 10 is also called a positive fault. A positive fault can also be said to be a fault that is discovered in the processing device 10.

[0012] On the other hand, even if the processed product discharged by the processing device 10 is judged to be a good product, the final product obtained by further processing the processed product in a later process may be a defective product. Some of these defective final products may be caused by the quality of the processed product discharged by the processing device 10. The occurrence of defective products in the final product reduces the yield. In other words, the processing device 10 may reduce the yield of the final product. Specifically, if the same part is continuously used in the processing device 10, the part deteriorates. The deterioration of the part causes a deterioration in the performance of the part or a deterioration in the performance of the processing device 10. Furthermore, if the processing device 10 is continuously used, at least a part of the processing device 10 deteriorates. The deterioration of the processing device 10 causes a deterioration in the performance of the processing device 10. If the processing device 10 continues processing in a state where the performance of the part or the processing device 10 has deteriorated, the quality of the processed product decreases. The deterioration of the quality of the processed product causes a decrease in the yield of the final product. The decrease in yield caused by the quality of the processed product causes losses in a form that is difficult to manifest in the processing device 10. A fault that causes losses in a manner that is difficult to manifest in the processing device 10 is also called a shadow fault. A shadow fault can also be said to be a fault that is not found in the processing device 10, but is found in a post-process after the processing of the target object. A positive fault causes the processing device 10 to stop. The stoppage of the processing device 10 causes an opportunity loss. The opportunity loss is determined based on the operation rate of the processing device 10.

[0013] The maintenance management system 1 or the maintenance management device 50 according to an embodiment of the present disclosure can manage the maintenance of the processing device 10, taking into consideration the opportunity loss included in a positive failure. The maintenance of the processing device 10 may include replacement of parts of the processing device 10, cleaning, greasing, etc. The maintenance management system 1 or the maintenance management device 50 may determine the maintenance interval or frequency of the processing device 10, or may determine the timing of maintenance of the processing device 10, as the management of the maintenance of the processing device 10. In other words, the maintenance of the processing device 10 is managed taking into consideration not only the cost of repairing a failure of the processing device 10 but also the opportunity loss caused by the stoppage of the processing device 10. In this way, the loss caused by the processing device 10 can be reduced.

[0014] Here, the processing device 10 is assumed to be configured to include a first part 11 (see FIG. 1). A positive or negative failure of the processing device 10 may occur due to deterioration such as wear or deformation of the first part 11. The maintenance management system 1 or the maintenance management device 50 according to the present embodiment can determine the replacement interval of the first part 11 as the maintenance management of the processing device 10. The replacement interval of the first part 11 corresponds to the time during which the processing device 10 is operated after the first part 11 is replaced with a new one in the processing device 10 until the first part 11 is next replaced with a new one. The maintenance management system 1 or the maintenance management device 50 may manage the maintenance of the processing device 10 by determining the frequency of part replacement or the timing of part replacement without being limited to determining the part replacement interval.

[0015] Furthermore, a manufacturing factory may have many processing devices 10. Even a small increase in the loss reduction amount per processing device 10 will result in a significant increase in the loss reduction amount for the entire manufacturing factory.

[0016] An example of the configuration of the maintenance management system 1 and the maintenance management device 50 according to an embodiment will be described below.

[0017] (System configuration example) As shown in FIG. 1, a maintenance management system 1 according to one embodiment includes a maintenance management device 50, an operation-related server 60, and a non-operational server 70.

[0018] The maintenance management device 50 includes a control unit 51, a communication unit 52, an output unit 53, and an input unit 54. The control unit 51 provides control and processing power for executing various functions of the maintenance management device 50. The control unit 51 generates information related to the maintenance of the processing device 10, as described below. The information related to the maintenance of the processing device 10 is also referred to as maintenance information. The maintenance information may include the maintenance interval, maintenance frequency, or maintenance timing of the processing device 10. The maintenance information may include information identifying the parts of the processing device 10 that are to be maintained.

[0019] The control unit 51 may include at least one processor. The processor may execute a program that realizes various functions of the control unit 51. The processor may be realized as a single integrated circuit. The integrated circuit is also called an IC (Integrated Circuit). The processor may be realized as a plurality of communicatively connected integrated circuits and discrete circuits. The processor may be realized based on various other known technologies.

[0020] The control unit 51 may include a storage unit. The storage unit may include an electromagnetic storage medium such as a magnetic disk, or may include a memory such as a semiconductor memory or a magnetic memory. The storage unit may include a non-transitory computer-readable medium. The storage unit stores various information and programs executed by the control unit 51. The storage unit may function as a work memory for the control unit 51. At least a part of the storage unit may be configured as a separate entity from the control unit 51.

[0021] The communication unit 52 is communicatively connected to other devices such as the operation server 60 or the non-operation server 70. The communication unit 52 may be communicatively connected to the processing device 10. The communication unit 52 may be communicatively connected to other devices via a network. The communication unit 52 may be communicatively connected to other devices by wire or wirelessly. The communication unit 52 may include a communication module that connects to a network or other devices. The communication module may include a communication interface such as a LAN (Local Area Network). The communication module may include a communication interface for non-contact communication such as infrared communication or NFC (Near Field communication). The communication module may realize communication by various communication methods such as 4G or LTE (Long Term Evolution). The communication method implemented by the communication unit 52 is not limited to the above examples and may include various other methods.

[0022] The output unit 53 outputs information acquired from the control unit 51. The output unit 53 may output information to notify an operator or a maintenance person of the processing apparatus 10. The output unit 53 may include a display device. The display device may include, for example, a liquid crystal display, an organic EL (Electroluminescence) display, an inorganic EL display, or the like, but is not limited to these, and may include other devices. The output unit 53 may display the information acquired from the control unit 51 on the display device as characters or images, etc., and notify the information to the surroundings.

[0023] The output unit 53 may include a light source such as an LED (Light Emission Diode) or a halogen lamp. The output unit 53 may notify an operator, maintenance personnel, or the like in the vicinity of information by turning on or blinking the light source based on information acquired from the control unit 51. The output unit 53 may include a buzzer such as a piezoelectric buzzer or an electromagnetic buzzer, or a speaker that emits a predetermined sound. The output unit 53 may notify an operator, maintenance personnel, or the like in the vicinity of information by sounding a buzzer or generating a sound from a speaker based on information acquired from the control unit 51.

[0024] The output unit 53 may output information to the processing apparatus 10. The output unit 53 may include a communication module so as to be communicatively connected to the processing apparatus 10.

[0025] The input unit 54 includes an input device for accepting operations or inputs by an operator or maintenance personnel managing the maintenance management apparatus 50. The input device may include, for example, a keyboard or physical keys, or may include a touch panel or a touch sensor, or a pointing device such as a mouse. When the input device is a touch panel or a touch sensor, it may be configured integrally with the display of the output unit 53. The input device may include, for example, a microphone that accepts voice input. The input device of the input unit 54 is not limited to these examples, and may include various other devices.

[0026] The operation system server 60 stores operation data of the entire factory. The operation data may include data such as the operating status or production volume of the processing device 10, quality data of the processed product or the final product discharged from the processing device 10, or yield data. The data stored in the operation system server 60 may include, for example, data measured by a measuring device. The operation system server 60 acquires the operation data from the processing device 10. The operation system server 60 outputs the operation data to the maintenance management device 50. The operation system server 60 may output the stored data in response to a request from the maintenance management device 50. The operation system server 60 may include at least one processor. The processor may be configured the same as or similar to the processor included in the control unit 51.

[0027] The non-operational server 70 stores data related to the processing device 10, such as labor costs or parts costs. The non-operational server 70 may constitute a database. The non-operational server 70 outputs the stored data to the maintenance management device 50. The non-operational server 70 may output the stored data in response to a request from the maintenance management device 50. The non-operational server 70 may include at least one processor. The processor may be configured identically or similarly to the processor included in the control unit 51. The non-operational server 70 may include a storage unit that stores data. The storage unit may be configured identically or similarly to the storage unit included in the control unit 51. The non-operational server 70 has a database that stores various information including equipment parts of the processing device 10 or the part costs, or labor costs. The database of the non-operational server 70 is also called a maintenance database (maintenance DB).

[0028] (Specific example of processing device 10: wire saw device) In this embodiment, it is assumed that the processing device 10 is a wire saw device. As shown in FIG. 2, the processing device 10 as a wire saw device includes a wire group 16 in which a wire 12 is stretched in parallel between a plurality of rollers 14 so as to be capable of reciprocating movement. The processing device 10 includes a workpiece holding mechanism 18 that holds the workpiece W and moves the workpiece W in a direction in which the workpiece W is pushed against the wire group 16. The processing device 10 includes a pair of nozzles 20 that supply slurry to an area of ​​the wire group 16 in which the workpiece W is pushed. The processing device 10 cuts the workpiece W with the wire group 16. It is assumed that the workpiece W is a block of silicon or the like (a single crystal ingot cut into a block shape). The processing device 10 delivers sliced ​​wafers of silicon or the like obtained by cutting the workpiece W as a processed product. Hereinafter, when the processing device 10 is a wire saw device, it is assumed that the processed product is a sliced ​​wafer.

[0029] The wire 12 is wound around a pair of wire reels 38A and 38B. The wire 12 is tensioned from one wire reel 38A through the guide roller 32, the roller 14, etc. to the other wire reel 38B.

[0030] The wire reels 38A and 38B are each rotated by a drive motor 36. When the drive motor 36 is driven to rotate the wire reels 38A and 38B, the wire 12 is unwound from one wire reel 38A and can run through the guide roller 32, roller 14, etc. to the other wire reel 38B. The wire 12 runs through a tension applying means including a dancer arm 33, dancer roller 34, etc. Tension is applied to the wire 12 as the wire 12 runs through the tension applying means. The wire 12 runs through a touch roller 35. The touch roller 35 follows the position of the wire 12 as it moves when it is unwound from the wire reels 38A and 38B or wound onto the wire reels 38A and 38B.

[0031] The wire 12 is wound helically multiple times across multiple rollers 14. The helically wound wire 12 constitutes a wire group 16 arranged in parallel between the rollers 14 in a direction perpendicular to the roller axial direction X. The rollers 14 are configured such that polyurethane resin is pressed around a steel cylinder, and grooves are cut into the surface at a fixed pitch. The wire 12 fits into the grooves cut into the surface of the rollers 14, allowing the wire group 16 to run stably.

[0032] The running direction of the wire 12 is controlled by the rotation direction of the drive motor 36. The wire 12 can be controlled to run in one direction, or can be controlled to run back and forth as necessary. The magnitude of tension applied to the wire 12 may be set as appropriate. The running speed of the wire 12 may be set as appropriate.

[0033] The slurry supplied from the nozzle 20 to the wire group 16 is stored in a slurry tank 40, and is sent from the slurry tank 40 to the nozzle 20 via a slurry chiller 42 that adjusts the temperature of the slurry.

[0034] As shown in FIG. 3, the guide roller 32 has a first part 11. The first part 11 is also simply referred to as a part. In this embodiment, the first part 11 is a guide roller bearing. As described later, the first part 11 is not limited to a guide roller bearing, and may be another part. The guide roller 32 is fitted around the axis of the guide roller bearing. The guide roller bearing is rotatably attached to the processing device 10. The guide roller 32 fitted into the guide roller bearing is rotatably attached to the processing device 10, and can smoothly advance the wire 12 while regulating the position of the wire 12.

[0035] The sliced ​​wafers discharged from the wire saw device are further processed in steps such as polishing, and are shipped as final wafer products.

[0036] (Example of conservation management method) The following describes a method in which the maintenance management device 50 manages the maintenance of the processing device 10. It is assumed that the replacement interval of the first component 11 (guide roller bearing) is determined by the method described below.

[0037] The maintenance management device 50 determines the replacement interval of the first part 11 based on the management cost required for replacement and the failure cost caused by the failure of the processing device 10. The longer the replacement interval of the first part 11, the lower the management cost but the higher the failure cost. Conversely, the shorter the replacement interval of the first part 11, the lower the failure cost but the higher the management cost. The smaller the sum of the management cost and the failure cost, the lower the running cost of the processing device 10 can be. Therefore, the maintenance management device 50 determines the replacement interval of the first part 11 so that the sum of the management cost and the failure cost is small. The maintenance management device 50 may determine the replacement interval of the first part 11 so that the sum of the management cost and the failure cost is minimized.

[0038] The maintenance management device 50 can determine the replacement interval of the first component 11 by a method described below so as to reduce the sum of the management cost and the failure cost.

[0039] <Management costs> The management cost is the cost of replacing the first part 11 (guide roller bearing). The cost of replacement is also called the replacement cost. The replacement cost includes the part cost of the guide roller bearing. The replacement cost further includes the labor cost of the replacement work. The replacement cost further includes the opportunity loss caused by stopping the processing equipment 10 during the replacement work. The opportunity loss corresponds to the value of sliced ​​wafers that could have been dispensed if the processing equipment 10 had been operated during the replacement work.

[0040] <Failure cost> The failure cost includes losses due to positive failures and losses due to negative failures.

[0041] <<Losses due to positive failures>> A positive failure is a failure that occurs with a predetermined occurrence probability. A positive failure may occur due to the first part 11. The occurrence probability of a positive failure caused by the first part 11 may be determined based on the state of the first part 11. It is assumed that the longer the operation time of the processing device 10 after the maintenance of the first part 11, the higher the occurrence probability of a positive failure caused by the first part 11. The operation time of the processing device 10 after the maintenance of the first part 11 is also referred to as the post-maintenance operation time. It is assumed that the occurrence probability of a positive failure caused by the first part 11 is proportional to the post-maintenance operation time.

[0042] The loss amount while no positive failure occurs is zero. However, a specified amount of loss occurs when a positive failure occurs. The loss amount due to a single positive failure is constant regardless of the timing of the positive failure. Since positive failures occur probabilistically, the expected amount of loss due to a positive failure is calculated. The expected amount of loss due to a positive failure is expressed as the product of the amount of loss due to a single positive failure and the probability of a positive failure occurring. If the probability of a positive failure occurring is proportional to the operating time after maintenance, the expected amount of loss due to a positive failure increases the longer the operating time after maintenance.

[0043] Here, the loss due to a positive failure is expressed by the expected value of the loss due to a positive failure. In order to reduce the loss due to a positive failure, it is effective to shorten the operation time after maintenance.

[0044] <<Losses due to shadow failures>> Unlike positive failures, negative failures are not failures that occur explicitly. A negative failure in a wire saw machine is not a failure that appears as an abnormality in the sliced ​​wafers discharged from the wire saw machine, but corresponds to a decrease in the yield of the wafers that become the final product. The amount of loss due to a negative failure corresponds to the reduced shipment value of the final product due to the decrease in the yield of the wafers that become the final product.

[0045] The deterioration of the first component 11 may reduce the yield of wafers that are final products and may increase the amount of loss due to shadow failures. The longer the operating time after maintenance, the more the deterioration of the first component 11 progresses and the more the amount of loss due to shadow failures may increase.

[0046] In order to reduce losses due to shadow failures, it is effective to shorten the operation time after maintenance.

[0047] <<Summary>> Both losses due to positive and negative failures can be reduced by shortening the time in operation after maintenance, i.e., the cost of failures can be reduced by shortening the time in operation after maintenance.

[0048] <Loss function> As described above, when the post-maintenance operation time of the processing device 10 is extended, the management cost is reduced but the breakdown cost may increase. On the other hand, when the post-maintenance operation time is shortened, the breakdown cost is reduced but the management cost increases. In other words, there is a trade-off between the management cost and the breakdown cost of the processing device 10 with respect to the post-maintenance operation time.

[0049] The control unit 51 of the maintenance management device 50 can calculate the post-maintenance operating time so as to reduce the sum of the management cost and the failure cost. The sum of the management cost and the failure cost is expressed as a loss function. The loss function is expressed, for example, by the following formula (1).

number

[0050] In formula (1), L(u) is the value of a loss function with the post-maintenance operating time represented by u as an argument. The first term on the right side of formula (1) represents the management cost. C is a constant representing the cost required to maintain the first part 11, and is also referred to as the maintenance cost. The maintenance cost includes the replacement cost required to replace the first part 11. The management cost of the first part 11 is proportional to the inverse of the post-maintenance operating time, and is reduced as the post-maintenance operating time of the first part 11 is extended. The second term on the right side of formula (1) represents the failure cost. A is a constant representing the loss due to a positive failure, and is also referred to as a positive failure loss. A' is a constant representing the loss due to a negative failure, and is also referred to as a negative failure loss. The symbol with - above u represents the mean time between failures for positive failures. When the symbol with - above u is used in the following description, it is written as "u-".

[0051] C is the sum of the cost of the first part 11 (guide roller bearing), the labor cost for the periodic replacement of the first part 11, and the opportunity loss amount. The labor cost is the product of the labor cost unit price and the labor time for the periodic replacement. The opportunity loss amount is the product of the amount representing the value of sliced ​​wafers that can be delivered per unit time and the labor time.

[0052] A is the sum of the amount representing the value of one block processed as the workpiece W, the cost of the first part 11 (guide roller bearing), the labor cost for repair work on the processing device 10 and replacement work for the first part 11, and the amount of opportunity loss. The labor cost is the product of the labor cost unit and the labor time for repair and replacement. The amount of opportunity loss is the product of the amount representing the value of sliced ​​wafers that can be delivered per unit time and the labor time for repair and replacement. The labor time for repair and replacement is longer than the labor time for regular replacement. Therefore, the labor cost for repair work is higher than the labor cost for regular replacement work. Furthermore, the amount of opportunity loss due to repair work is higher than the amount of opportunity loss for regular replacement work.

[0053] A' is the product of the production value of the final product wafers when the yield is assumed to be 100%, the rate of decline in the yield of the final product wafers, the square of the time until the processing equipment 10 breaks down, and 1 / 2. It is assumed that the wafer yield declines at a rate proportional to the operating time after maintenance. The product of the rate of decline in the yield of the final product wafers, the square of the time until the processing equipment 10 breaks down, and 1 / 2 represents the cumulative yield decline until the processing equipment 10 breaks down.

[0054] The equation expressing the loss function is not limited to the above equation (1), and may be expressed in other forms including terms corresponding to positive and negative faults. The equation expressing the loss function may be expressed as an equation including at least one of the above C, A, and A'. The equation expressing the loss function is not limited to the above C, A, and A', and may be expressed as an equation including other constants.

[0055] The control unit 51 calculates values ​​of constants such as C, A, and A' included in the equation representing the loss function, and generates the loss function. The control unit 51 acquires parameters necessary for calculating the values ​​of each constant. The parameters necessary for calculating the values ​​of each constant are also referred to as element parameters. The control unit 51 may acquire information on parts such as the first part 11 constituting the processing device 10 as element parameters. The information on the parts is also referred to as part information. The control unit 51 may acquire information on labor management of staff who perform maintenance work such as repair work or part replacement work on the processing device 10 as element parameters. The information on labor management of staff is also referred to as labor management information. The control unit 51 may acquire information on the operating status or production number of the processing device 10, or information on the yield of the wafers of the final product as element parameters. The information on the operating status or production number, or the yield of the wafers is also referred to as operation information. The control unit 51 may calculate each constant included in the equation representing the loss function based on the part information, labor management information, or operation information, and generate the loss function.

[0056] The parts information, labor management information, or operation information may be stored in a maintenance DB of the non-operational server 70. The control unit 51 may acquire the parts information, labor management information, or operation information as element parameters from the maintenance DB of the non-operational server 70. The maintenance management device 50 may further include a communication device communicatively connected to the non-operational server 70 via wired or wireless communication. The non-operational server 70 may acquire the parts information, labor management information, or operation information from an external device and store it in the database. The non-operational server 70 may store the parts information, labor management information, or operation information input by an administrator, or an operator or maintenance person of the processing device 10, in the database.

[0057] The control unit 51 may acquire the operation information as element parameters from the operation-related server 60. The maintenance management apparatus 50 may further include a communication device connected to the operation-related server 60 so as to be able to communicate with the operation-related server 60 via wired or wireless communication.

[0058] The control unit 51 may acquire element parameters necessary for calculating the value of each parameter based on an input from a user. The maintenance management device 50 may receive an input from a user via the input unit .

[0059] The control unit 51 calculates the values ​​of the constants included in the equation expressing the loss function based on the acquired element parameters, and generates the loss function. In this embodiment, the control unit 51 generates the loss function by calculating the values ​​of the constants in the above-mentioned equation (1).

[0060] The maintenance management device 50 determines the replacement interval of the first component 11 so as to reduce the value of the loss function (L(u)). FIG. 4 illustrates a graph showing the relationship between the operating time after maintenance (u) and the value of the loss function (L(u)). In FIG. 4, the horizontal axis represents the operating time after maintenance (u), and the vertical axis represents the value of the loss function (L(u)). The value of the loss function (L(u)) is represented, for example, as a solid line graph. The dashed and dotted line graphs represent the values ​​of the first and second terms on the right-hand side of equation (1), respectively. The first term on the right-hand side corresponds to the management cost, and L A(u). The second term on the right side corresponds to the failure cost, L B (u). L(u)=L A (u)+L B (u) holds. The value of the loss function can correspond to a value that represents the magnitude of the loss converted into a monetary value.

[0061] According to the graph of L(u) shown in FIG. 1 It has been shown that the loss function reaches a minimum value at the point where L 1 It is expressed as L 1 =L(u 1 ) holds. When the loss function is expressed by equation (1), the loss function value (L(u)) becomes the minimum value (L 1 ) when the post-maintenance operation time (u 1 ) is expressed by the following equation (2).

number

[0062] The control unit 51 sets the replacement interval of the first component 11 as u 1 The control unit 51 may determine the replacement interval of the first component 11 to be u within a range in which the increase in the value of the loss function from the minimum value is within a predetermined value. 1 Longer or shorter intervals may be used, which may mitigate errors in the loss function.

[0063] For the following reasons, the control unit 51 sets the replacement interval of the first component 11 to u 1 You can use a longer interval. The rate of change of the loss function graph is the minimum value of the loss function, u=u 1 The rate of change of the loss function graph is u 1 It becomes negative at the point where u>u 1 The rate of change in the graph of the loss function is expressed as a function obtained by first differentiating the loss function (L(u)) with respect to u. The function obtained by first differentiating L(u) contains the inverse of the square of u. Therefore, the absolute value of the rate of change in the graph of the loss function is u = u 1 Rather than the point -Δu, u=u​1 +Δu, where Δu is a positive constant. From this, the increase from the minimum value of the value of the loss function when the control unit 51 makes the replacement interval of the first component 11 longer than u1 is smaller than the increase from the minimum value of the value of the loss function when the control unit 51 makes the replacement interval of the first component 11 shorter than u1. In other words, when the control unit 51 makes the replacement interval of the first component 11 shorter than u1, 1 A longer spacing reduces the likelihood of increased losses.

[0064] The value of u when the loss function is a local minimum value coincides with the value of u when the equation obtained by first differentiating the loss function with respect to u is zero. The control unit 51 may generate in advance the equation obtained by first differentiating the loss function with respect to u. In this way, the local minimum value of the loss function can be calculated easily.

[0065] The control unit 51 may determine the next timing for replacing the first component 11 based on the determined replacement interval and the timing when the first component 11 was previously replaced.

[0066] The control unit 51 causes the output unit 53 to output information regarding the determined replacement interval of the first part 11 or the timing for the next replacement of the first part 11. The information regarding the replacement interval of the first part 11 or the timing for the next replacement of the first part 11 is also referred to as replacement information of the first part 11. The replacement information of the first part 11 is included in the maintenance information of the processing device 10. The output unit 53 may output the maintenance information as visual information or auditory information, etc., and notify the maintenance person of the processing device 10. The maintenance person of the processing device 10 may plan and execute the replacement work of the first part 11 in the processing device 10 based on the maintenance information of the first part 11.

[0067] The output unit 53 may output the information to the processing device 10. When the output unit 53 outputs the information to the processing device 10, the processing device 10 may output an alarm notifying the timing of replacing the first component 11 based on the acquired information, or may stop the processing device 10 itself in accordance with the timing of replacing the first component 11.

[0068] The positive failure loss includes opportunity loss caused by the processing equipment 10 stopping due to a failure. The opportunity loss is represented by A1. The positive failure loss includes defective loss caused by the processing equipment 10 discharging defective products due to a failure. The defective loss is represented by A2. The positive failure loss includes the replacement cost of the failed part. The replacement cost is represented by A3.

[0069] The opportunity loss is determined based on the time during which the processing device 10 is stopped. Also, the opportunity loss is determined based on the operating status when the processing device 10 is not stopped. For example, the higher the operating rate of the processing device 10 in a predetermined period before the processing device 10 is stopped, the greater the opportunity loss of the processing device 10.

[0070] In this embodiment, it is assumed that the processing device 10 stops for a predetermined time. The opportunity loss when the processing device 10 stops for a predetermined time is represented by A1. As described above, the opportunity loss is also determined based on the operation status of the processing device 10. In this embodiment, it is assumed that a coefficient based on the operation status of the processing device 10 is determined. The coefficient based on the operation status of the processing device 10 is represented by a. If the opportunity loss when the operation rate of the processing device 10 is assumed to be 100% is represented by A1, a corresponds to the operation rate of the processing device 10. If the opportunity loss when the operation rate of the processing device 10 is assumed to be 80% is represented by A1, a corresponds to the value obtained by multiplying the operation rate of the processing device 10 by 1.25 (the reciprocal of 80%). By determining a as described above, the opportunity loss of the processing device 10 is represented by aA1.

[0071] From the above, in this embodiment, the positive failure loss (A) is expressed by the following formula (3). In other words, the failure cost in the second term of the loss function is expressed in a form including a value obtained by multiplying the opportunity loss (A1) by a coefficient (a) based on the operating status of the processing device 10.

number

[0072] Moreover, a loss function La reflecting a coefficient (a) based on the operating status of the processing device 10 is expressed by the following formula (4).

number

[0073] In the following description, the opportunity loss when the operation rate of the processing device 10 is assumed to be 100% is represented by A1. Therefore, a corresponds to the operation rate of the processing device 10. In this case, a is set to a value equal to or greater than 0 and equal to or less than 1.

[0074] The first term on the right hand side of the loss function represented by La(u,a) does not include a, so La A (u). The second term on the right side includes a, so La B (u, a). Based on the above notation, La(u, a) = La A (u)+La B (u,a) holds.

[0075] The maintenance management device 50 determines the replacement interval of the first component 11 so as to reduce the value of the loss function (La(u, a)). The value of u when the value of La(u, a) is the minimum value is expressed by the following equation (5).

number

[0076] Considering that a corresponds to the operation rate of the processing device 10, if the operation rate of the processing device 10 at the present time is lower than the assumed operation rate at the time the loss function is generated, the value of u when the value of La(u, a) becomes the minimum value becomes large. Conversely, if the operation rate of the processing device 10 at the present time is higher than the assumed operation rate at the time the loss function is generated, the value of u when the value of La(u, a) becomes the minimum value becomes small. By changing the loss function according to the operation rate of the processing device 10 at the present time, maintenance of the processing device 10 can be performed at the timing when the value of La(u, a) becomes the minimum value according to the operation rate of the processing device 10 at the present time.

[0077] The following describes the change in the value of La(u, a) when the operation rate of the processing device 10 is assumed to be 100% but the actual operation rate is lower. In FIG. 5, a graph of the loss function (La(u, 1)) when the operation rate of the processing device 10 is assumed to be 100% (a=1) and a graph of the loss function (La(u, 0.2)) when the operation rate of the processing device 10 actually becomes 20% (a=0.2) are shown by solid lines. The horizontal axis represents the operation time after maintenance (u). The vertical axis represents the value of the loss function (La(u, a)). The dashed-dotted line graph represents the value of the first term on the right-hand side of equation (4) (La A (u)). The dashed line graph shows the value of the second term on the right side of equation (4) (La B (u,a)).

[0078] The value of u when La(u,0.2) becomes the minimum value is u 0.2 In this case, the minimum value is La 0.2 The value of u when La(u,1) becomes the minimum value is u 1 In this case, the minimum value is La 1 The magnitude relationship of the value of u is expressed as u 0.2 >u 1 The relationship between the minimum values ​​is as follows: La 0.2 <L 1 It is as follows.

[0079] When the operation rate of the processing device 10 becomes 20%, the maintenance management device 50 can substitute 0.2 for a and update the loss function to La(u,0.2) that matches the current state. The maintenance management device 50 can update the replacement interval of the first part 11 from the initially expected interval (u 1 ) longer than the interval (u 0.2 ) can be updated.

[0080] By updating the loss function and the replacement interval, the value of the loss function is La 0.2 If the replacement interval is the initially expected u 1 If it is left as it is, the loss function (La(u 1 ,0.2)) is the value of LC It becomes. L C La 0.2 From L D If the replacement interval is updated, the loss is La 0.2 By leaving the replacement intervals at intervals calculated assuming 100% availability, an opportunity to reduce losses is lost. In other words, losses can be reduced by updating the replacement intervals based on the actual availability.

[0081] Conversely, even if the operating rate of the processing device 10 becomes higher than expected, losses can be reduced by updating the replacement interval based on the actual operating rate.

[0082] As described above, the maintenance management device 50 can determine the replacement interval of the first part 11 of the processing device 10 based on the management cost, the positive failure loss including the opportunity loss, the negative failure loss, and the operating rate of the processing device 10, and can manage the maintenance of the processing device 10. In this way, the loss caused by the processing device 10 can be reduced.

[0083] As an example of an embodiment, a configuration example has been described in which the replacement interval of the first part 11 is determined based on an opportunity loss reflecting the operation rate of the processing device 10. The maintenance management device 50 can also determine the replacement interval of the first part 11 without generating a loss function. The maintenance management device 50 may, for example, acquire data on the operation rate of the processing device 10 from the operation server 60, and feed back the operation rate of the processing device 10 to the replacement interval of the first part 11.

[0084] (Confirmation of cost reduction by determining replacement intervals taking opportunity loss into account) A specific example of cost reduction for the processing device 10 will be described below. In this example, the average failure frequency (u-) when the processing device 10 has an operating rate of 100% is assumed to be one year. The cost of replacing parts (C) is assumed to be 2 million yen. The opportunity loss (A1) when the processing device 10 has an operating rate of 100% is assumed to be 5 million yen. The defective loss (A2) caused by a breakdown of the processing device 10 is assumed to be 1 million yen. The cost of replacing parts of the processing device 10 (A3) is assumed to be 2 million yen.

[0085] Under the above preconditions, assuming that the operation rate of the processing device 10 is 100%, the optimal periodic replacement interval for parts is 0.71 years (u in FIG. 5). 1 Here, when the actual operating rate of the processing device 10 is 20%, the optimal periodic replacement interval for the parts is calculated as 1.00 years (corresponding to u in FIG. 5). 0.2 In this way, the cost increases by replacing the parts every 0.71 years while assuming a 100% availability rate. The increased cost compared to replacing the parts every 1.00 years (L in Figure 5) D In other words, by determining the replacement interval of the first part 11 while taking into consideration the opportunity loss, a cost reduction of 240,000 yen can be realized.

[0086] (Example of conservation management procedure) The control unit 51 of the maintenance management device 50 may execute a maintenance management method including the steps of a flowchart illustrated in Fig. 6, for example. By executing the illustrated maintenance management method, the control unit 51 can determine the replacement interval of the first part 11 of the processing device 10 based on the shadow failure loss and manage the maintenance of the processing device 10. The maintenance management method may be realized as a maintenance management program executed by the control unit 51. The steps illustrated in Fig. 6 are an example and may be modified as appropriate.

[0087] The control unit 51 acquires element parameters (step S1).

[0088] The control unit 51 sets a constant of the loss function (step S2). Specifically, the control unit 51 calculates and sets the constant of the loss function based on the values ​​of the element parameters acquired in the procedure of step S1. The control unit 51 assumes the operation rate of the processing device 10 and sets the value of a as the constant of the loss function. The control unit 51 may set the values ​​of A1, A2, and A3, and C and A' as the constants of the loss function.

[0089] The control unit 51 determines the replacement interval of the first component 11 (step S3). Specifically, the control unit 51 may calculate the post-maintenance operating time of the first component 11 when the value of the loss function to which the constant is set in the procedure of step S2 becomes a minimum value, and determine the calculated value as the replacement interval of the first component 11.

[0090] The control unit 51 outputs the maintenance information (step S4). Specifically, the control unit 51 may output the replacement interval of the first part 11 determined in the procedure of step S3 as the maintenance information. The control unit 51 may further acquire the timing at which the first part 11 was previously replaced, and may determine the timing at which the first part 11 will be next replaced based on the replacement interval of the first part 11 determined in the procedure of step S3 and the timing at which the first part 11 was previously replaced. The control unit 51 may output the timing at which the first part 11 will be next replaced as the maintenance information. The control unit 51 may output the maintenance information to the output unit 53 of the maintenance management device 50. The output unit 53 may notify the maintenance personnel of the processing device 10 of the acquired maintenance information by displaying it on a display device or announcing it via an audio output device. The control unit 51 may output the maintenance information to the processing device 10. Based on the acquired maintenance information, the processing device 10 may output an alarm notifying the user of the timing for replacing the first component 11, or the processing device 10 may stop itself in accordance with the timing for replacing the first component 11.

[0091] The control unit 51 determines whether the operation rate of the processing device 10 has changed (step S5). If the operation rate of the processing device 10 has changed (step S5: YES), the control unit 51 returns to the procedure of step S2 and updates the value of a as a constant of the loss function. If the operation rate of the processing device 10 has not changed (step S5: NO), the control unit 51 ends the execution of the procedure of the flowchart in Fig. 6. The control unit 51 may repeat the determination procedure of step S5.

[0092] In the determination procedure of step S5, the control unit 51 may set a threshold value for the amount of change in the operation rate, and if the operation rate changes more than the threshold value, the control unit 51 may return to the procedure of step S2 and update the value of a as the constant of the loss function. The threshold value may be determined based on the magnitude of the impact that the change in the operation rate has on costs. Feeding back the change in the operation rate to the part replacement interval at a stage when the impact on costs is small increases the management burden. By setting a threshold value for the amount of change in the operation rate, the management burden of the part replacement interval can be reduced.

[0093] As described above, according to the maintenance management method and the maintenance management program of the present embodiment, the replacement interval of the first part 11 of the processing device 10 can be determined based on the opportunity loss reflecting the operation rate of the processing device 10. In this way, the maintenance cost of the processing device 10 can be reduced. As a result, losses in the manufacturing plant can be reduced.

[0094] A manufacturing factory may have a large number of processing devices 10. By increasing the loss reduction amount per processing device 10 even slightly, the loss reduction amount for the entire manufacturing factory can be sufficiently large.

[0095] Furthermore, when the quality data or the state of the processing device 10 changes, the maintenance management device 50 can update the loss function by simply changing the value of the operation rate (a) of the processing device 10, instead of regenerating the loss function. This can reduce the load of calculations required to generate the loss function. In other words, the load on the control unit 51 of the maintenance management device 50 can be reduced. As a result, the maintenance management device 50 can simply feed back the operation rate of the processing device 10 to the loss function.

[0096] In addition, the maintenance management device 50 may recalculate the management cost and the failure cost after carrying out regular replacement of a part of the processing device 10, and may extend or shorten the optimal regular replacement interval.

[0097] Furthermore, the maintenance management device 50 may recalculate the optimal periodic replacement interval at an interval shorter than the optimal periodic replacement interval. The maintenance management device 50 may update the optimal periodic replacement interval when the cost determined based on the recalculation result of the optimal periodic replacement interval is reduced by a predetermined threshold or more compared to the cost before the recalculation. In this way, the complexity of managing the optimal periodic replacement interval can be reduced.

[0098] (Other embodiments) <Application to equipment other than wire saw equipment or parts other than guide roller bearings> In the embodiment described above, the first part 11 corresponds to a guide roller bearing. The first part 11 is not limited to a guide roller bearing, and may correspond to other parts such as the guide roller 32, the dancer roller 34, or the touch roller 35. The maintenance management device 50 is not limited to determining the replacement interval of the guide roller bearing as the replacement interval of the first part 11, and may determine the replacement interval of other parts such as the guide roller 32, the dancer roller 34, or the touch roller 35, and manage the maintenance of the processing device 10.

[0099] The maintenance management device 50 may determine the replacement interval for not only one part but also a part group including a combination of two or more parts, and manage the maintenance of the processing device 10. For example, parts other than the first part 11 constituting the processing device 10 are also referred to as second parts. The maintenance management device 50 may determine the replacement interval for a part group including a combination of the first part 11 and a second part. When the first part 11 is a guide roller bearing, the second part may be a guide roller 32. The combination of two or more parts included in the part group is not limited to the above example.

[0100] In the embodiment described above, the processing apparatus 10 corresponds to a wire saw apparatus. The processing apparatus 10 is not limited to a wire saw apparatus, and may correspond to other apparatus such as a polishing apparatus. The maintenance management apparatus 50, as the processing apparatus 10, may not only manage the maintenance of the wire saw apparatus, but also manage the maintenance of other apparatus such as a polishing apparatus. When the processing apparatus 10 is another apparatus, the processed product corresponds to an article other than a sliced ​​wafer.

[0101] (Consideration of implicit failure loss in functions other than loss function) The maintenance management device 50 according to the embodiment described above formulates the relationship between the maintenance of the processing device 10 and the opportunity loss by a loss function, and manages the maintenance of the processing device 10 by reducing the value of the loss function. The maintenance management device 50 may formulate the relationship between the maintenance of the processing device 10 and the loss by other functions, not limited to the loss function. The maintenance management device 50 may manage the maintenance of the processing device 10 by generating a function that takes opportunity loss into consideration in a function based on the failure rate of the processing device 10, the amount of damage when a failure occurs, and the probability of overlooking a failure symptom, as described in JP 2004-152017 A, for example.

[0102] <Maintenance management based on individual conditions of processing device 10> As described above, in order to calculate an appropriate maintenance interval for the processing device 10 or a part used in the processing device 10, a loss function model including a management cost and a failure cost (positive failure cost and negative failure cost) is used. The failure cost is formulated based on the loss when the processing device 10 breaks down and the probability of the failure occurring. The failure cost may vary depending on the superiority or inferiority of the processing device 10 or the difference in the environment in which the processing device 10 operates. When a loss function model that does not consider the superiority or inferiority of the processing device 10 or the difference in the environment in which the processing device 10 operates is used, the processing device 10 may be maintained at a timing when it is highly likely that it will not break down. In addition, the processing device 10 may break down before it is maintained. Hereinafter, a configuration that realizes optimization of the maintenance interval for the processing device 10 and reduction of the maintenance cost by using a loss function model that considers the fluctuation of the failure cost according to the superiority or inferiority of the processing device 10 or the difference in the environment in which the processing device 10 operates will be described.

[0103] The maintenance management device 50 uniformly sets the mean time between failures (u-) of each of the processing devices 10 installed in the process based on the result of statistically processing the data of the maintenance performance of each processing device 10. However, each processing device 10 operates under different conditions. For example, the processing devices 10 operate in different environments. The environment in which the processing device 10 operates may include the air environment such as the temperature or humidity of the place where the processing device 10 is installed, or the environment of the auxiliary equipment such as the cooling water supply system or the material supply system to which the processing device 10 is connected. In addition, each processing device 10 may have individual differences. The individual differences of the processing devices 10 may be caused by various factors such as the workmanship at the time of manufacturing the processing device 10, the specifications of the processing device 10, the total operating time of the processing device 10, or the maintenance history of the processing device 10. The tendency of the processing devices 10 to break down when operating under different conditions is different. In other words, the mean time between failures may be different for each processing device 10.

[0104] Therefore, the maintenance management device 50 may assume that the mean time between failures of each processing device 10 differs depending on characteristic factors such as differences in the environment or individual differences of each processing device 10, and set a loss function that takes into account the mean time between failures of each processing device 10 for each processing device 10.

[0105] Here, the processing device 10 includes a first processing device and a second processing device. The maintenance management device 50 calculates the initial value of the mean time between failures of each of the first processing device and the second processing device. The maintenance management device 50 acquires operation data when each of the first processing device and the second processing device is operated. The maintenance management device 50 estimates the operation time from maintenance to failure for each of the first processing device and the second processing device. The maintenance management device 50 updates the mean time between failures of each of the first processing device and the second processing device based on a comparison between the estimated operation time and the initial value of the mean time between failures. Specifically, the maintenance management device 50 makes the mean time between failures longer than the initial value when the estimated operation time is longer than the initial value of the mean time between failures, and makes the mean time between failures shorter than the initial value when the estimated operation time is shorter than the initial value of the mean time between failures. In this way, the mean time between failures of each of the first processing device and the second processing device can be updated to different values.

[0106] The maintenance management device 50 sets a mathematical expression of a loss function model for each of the first processing device and the second processing device. Instead of updating the value of the mean time between failures (u-) included in the second term on the right side of the equation (1) of the loss function model, the maintenance management device 50 generates a loss function model Lb by introducing a correction coefficient b for correcting the coefficient of the second term on the right side as shown in the following equation (6).

number

[0107] In equation (6), the mean time between failures (u-) is assumed to remain unchanged from its initial value. The state in which the actual mean time between failures differs from the initial value is represented by the correction coefficient b. For example, the state in which the mean time between failures has become p times the initial value is reflected in the loss function model by setting the correction coefficient b to 1 / (p^2).

[0108] When the maintenance management device 50 lengthens the mean time between failures (u-), it sets the value of the correction coefficient b to a value smaller than 1, instead of changing the value of the mean time between failures (u-). Conversely, when the maintenance management device 50 shortens the mean time between failures (u-), it sets the value of the correction coefficient b to a value larger than 1, instead of changing the value of the mean time between failures (u-). In this way, the superiority or inferiority of the processing device 10 or the environment in which the processing device 10 is operating is reflected in the loss function model Lb.

[0109] The first term on the right hand side of the loss function represented by Lb(u,b) does not include b, so Lb A (u). The second term on the right side includes b, so Lb B (u, b). Based on the above notation, Lb(u, b) = Lb A (u)+Lb B (u,b) holds.

[0110] The change in the value of Lb(u,b) when the mean time between failures of the processing equipment 10 is longer than the initial value will be explained below. In FIG. 7, a graph of the loss function (Lb(u,1)) when it is assumed that the mean time between failures of the processing equipment 10 remains at the initial value, and a graph of the loss function (Lb(u,0.8)) when the mean time between failures of the processing equipment 10 becomes longer than the initial value and the correction coefficient b becomes 0.8 are shown by solid lines. The horizontal axis represents the operating time after maintenance (u). The vertical axis represents the value of the loss function (Lb(u,b)). The dashed-dotted line graph represents the value of the first term on the right-hand side of equation (6) (Lb A (u)). The dashed line graph represents the value of the second term on the right side of equation (6) (Lb B (u,b)).

[0111] The value of u when Lb(u,0.8) becomes the minimum value is u 0.8 In this case, the minimum value is Lb 0.8 The value of u when Lb(u,1) becomes the minimum value is u 1 In this case, the minimum value is Lb 1 The magnitude relationship of the value of u is expressed as u0.8 >u 1 The relationship between the minimum values ​​is as follows: Lb 0.8 <Lb 1 It is as follows.

[0112] When the mean time between failures of the processing device 10 becomes longer than the initial value and the correction coefficient b becomes 0.8, the maintenance management device 50 can substitute 0.8 for b and update the loss function to Lb(u,0.8) that matches the current state. The maintenance management device 50 can update the replacement interval of the first part 11 to the interval (u) that was initially expected based on the value of u at which the updated loss function (Lb(u,0.8)) becomes a minimum value. 1 ) longer than the interval (u 0.8 ) can be updated.

[0113] By updating the loss function and replacement interval, the value of the loss function is Lb 0.8 It became. Lb 0.8 If the replacement interval is the initially assumed u 1 , which is smaller than the value of the loss function if it had been left as is. Thus, by updating the replacement interval based on the actual mean time between failures, losses can be reduced.

[0114] Conversely, even if the mean time between failures of the processing device 10 becomes shorter than the initial value, losses can be reduced by updating the replacement interval based on the actual mean time between failures.

[0115] As described above, the maintenance management device 50 can determine the replacement interval of the first part 11 of the processing device 10 based on the management cost, the positive failure loss including the opportunity loss, the negative failure loss, and the mean time between failures of the processing device 10, and can manage the maintenance of the processing device 10. In this way, the loss caused by the processing device 10 can be reduced.

[0116] As an example, a case will be described where the replacement interval is updated taking into consideration the mean time between failures of the wire saw device as the processing device 10. It is assumed that the mean time between failures of the wire saw device is updated from the initial value to be set to 0.7 years. It is assumed that the cost of maintenance such as replacing parts of the wire saw device is 2 million yen. It is also assumed that the opportunity loss when the wire saw device breaks down and the loss due to product defects are 8 million yen. The maintenance management device 50 sets the replacement interval of the wire saw device to 0.7 years based on the mean time between failures of the wire saw device being set to 0.7 years.

[0117] Here, it is assumed that the current mean time between failures of the wire saw device has been extended to an interval longer than 0.7 years. In this case, if the replacement interval of the wire saw device is set to 0.7 years, the timing of maintenance will be too early. If the timing of maintenance is too early, the management cost of the first term on the right side of the loss function will be high. As a result, the overall loss will be large. Therefore, the maintenance management device 50 reduces the failure cost of the second term on the right side of the loss function by reducing the correction coefficient b. Then, it is assumed that when the correction coefficient b is set to 0.8, the replacement interval at which the loss function has a minimum value is 0.8 years. By extending the replacement interval from 0.7 years to 0.8 years, the overall cost has been reduced by 600,000 yen compared to when the replacement interval was left set to 0.7 years.

[0118] Conversely, if the current mean time between failures of the wire saw machine is shorter than 0.7 years, then by increasing the correction factor b, overall costs can be reduced.

[0119] The maintenance management device 50 may repeatedly review the setting of the mean time between failures, i.e., the correction coefficient b, for each processing device 10. The value of the correction coefficient b that has been repeatedly reviewed may converge to a certain range. Specifically, if the correction coefficient b is set to a value that is too small, the processing device 10 may show signs of failure or break down earlier than the replacement interval. Conversely, if the correction coefficient b is set to a value that is too large, the processing device 10 may not show any signs of failure or break down at all, even when the replacement interval has arrived.

[0120] The maintenance management device 50 may set a stable region in which the value of the correction coefficient b when the probability of updating the correction coefficient b in a direction to increase becomes less than a predetermined probability is an upper limit, and the value of the correction coefficient b when the probability of updating the correction coefficient b in a direction to decrease becomes less than a predetermined probability is a lower limit, based on a result of repeatedly reviewing the value of the correction coefficient b. The predetermined probability may be set appropriately. When the correction coefficient b converges within the range of the stable region, the maintenance management device 50 may determine whether to update the correction coefficient b so that the correction coefficient b is unlikely to fall outside the stable region. For example, when changing the correction coefficient b within the stable region, the maintenance management device 50 may change the correction coefficient b based on operation data of one cycle from when the machining device 10 is maintained until the next maintenance. When changing the correction coefficient b outside the stable region, the maintenance management device 50 may change the correction coefficient b based on operation data of multiple cycles from when the machining device 10 is maintained until the next maintenance.

[0121] The maintenance management device 50 may calculate statistical values ​​such as the average value of the operating data for multiple cycles from when the processing device 10 is maintained until the next maintenance, and review the value of the correction coefficient b based on the calculation results of the statistical values.

[0122] The maintenance management device 50 may generate a loss function (Lab(u, a, b)) that reflects both a coefficient a related to the operating rate of the processing device 10 and a coefficient b related to the mean time between failures of the processing device 10, and manage the maintenance of the processing device 10.

[0123] Although the embodiments according to the present disclosure have been described based on the drawings and examples, it should be noted that a person skilled in the art can make various modifications or alterations based on the present disclosure. Therefore, it should be noted that these modifications or alterations are included in the scope of the present disclosure. For example, the functions included in each component or each step can be rearranged so as not to be logically inconsistent, and multiple components or steps can be combined into one or divided. Although the embodiments according to the present disclosure have been described mainly with respect to the device, the embodiments according to the present disclosure can also be realized as a method including steps executed by each component of the device. The embodiments according to the present disclosure can also be realized as a method, a program, or a storage medium on which a program is recorded, executed by a processor included in the device. It should be understood that these are also included in the scope of the present disclosure.

[0124] The graphs included in this disclosure are schematic and do not necessarily correspond to the actual scale. [Industrial Applicability]

[0125] According to embodiments of the present disclosure, losses in the manufacturing process may be reduced. [Explanation of symbols]

[0126] 1 Maintenance Management System 10 Processing device (11: first part (guide roller bearing), 12: wire, 14: roller, 16: wire group, 18: work holding mechanism, 20: nozzle, 32: guide roller, 33: dancer arm, 34: dancer roller, 35: touch roller, 36: drive motor, 38: wire reel, 40: slurry tank, 42: slurry chiller, W: work (block), X: roller axis direction) 50 Maintenance management device (51: control unit, 52: communication unit, 53: output unit, 54: input unit) 60 Operational Server 70 Non-operational server (maintenance DB)

Claims

1. A control unit that determines maintenance information including information for identifying a maintenance interval, a maintenance frequency, or a maintenance timing of a processing device that produces a processed product, or a part of the processing device that is to be maintained; an output unit that outputs the security information determined by the control unit; Equipped with The control unit determines the maintenance information based on a maintenance cost required for maintaining the processing device and a failure cost caused by the processing device; The failure cost includes a value obtained by multiplying an opportunity loss corresponding to the value of the processed product that could have been delivered if the processing device had not broken down and stopped by a coefficient based on the operation rate of the processing device. Maintenance management device.

2. The control unit is a loss function is generated using a post-maintenance operation time corresponding to the time during which the processing device is operated after the maintenance of the processing device as an argument, the loss function being expressed as the sum of a first term proportional to the product of the inverse of the post-maintenance operation time and the maintenance cost, and a second term proportional to the product of the post-maintenance operation time and the failure cost; The maintenance management device according to claim 1 , wherein the maintenance information is determined based on the loss function.

3. The maintenance management device according to claim 2 , wherein the control unit calculates, as the maintenance information, the post-maintenance operating time when the value of the loss function is a minimum value or is within a predetermined range of the minimum value.

4. The maintenance management device according to claim 2 or 3, wherein the control unit generates the loss function in a form in which the failure cost in a second term of the loss function is multiplied by a coefficient based on a characteristic factor of the processing device.

5. A maintenance management device determines maintenance information including a maintenance interval, a maintenance frequency, or a maintenance timing of a processing device that produces a processed product, or information identifying a part of the processing device that is to be maintained, based on a maintenance cost required for maintaining the processing device and a failure cost caused by the processing device; the maintenance management device outputs the determined maintenance information; Including, The failure cost includes a value obtained by multiplying an opportunity loss corresponding to the value of the processed product that could have been delivered if the processing device had not broken down and stopped by a coefficient based on the operation rate of the processing device. Conservation management methods.

6. The processor: determining maintenance information including a maintenance interval, a maintenance frequency, or a maintenance timing of a processing device that produces a processed product, or information identifying a part of the processing device that is to be maintained, based on a maintenance cost required for maintaining the processing device and a failure cost caused by the processing device; outputting the determined maintenance information; Run the command, The failure cost includes a value obtained by multiplying an opportunity loss corresponding to the value of the processed product that could have been delivered if the processing device had not broken down and stopped by a coefficient based on the operation rate of the processing device. Conservation management programs.

Images