JP2010204764A - Device and method for creating maintenance plan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To create a maintenance plan for efficiently maintaining a plurality of components. <P>SOLUTION: A device for creating the maintenance plan is provided with: a first calculation part 132 for inputting, to functions determined for each component which inputs a replacement period, and outputs expected cost in each of a plurality of reference periods and each of components, a replacement period expressed by the multiple of a reference cycle being replacement periods before and after a replacement period to output the minimum value of expected cost, and for calculating the minimized period expressing the replacement period whose expected cost to be outputted is small; a second calculation part 134 for calculating the optimal reference period representing the reference period to minimize the sum of the expected costs of each component to be outputted by inputting the minimized period to the functions and maintenance staff's cost required for the replacement of the reference periods among the plurality of reference periods; and a creation part 140 for creating a maintenance plan showing replacement with the minimized period calculated with respect to the optimal reference period for each component. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an apparatus and a method for creating a maintenance plan for each part of a device having a plurality of parts.

  In manufacturing equipment and large equipment, a plurality of parts are generally used in one equipment, and maintenance (maintenance) such as inspection and replacement is particularly required for parts that are severely deteriorated over time. Currently, various maintenance measures that can be applied to such devices have been proposed (for example, Patent Document 1, Patent Document 2, and Non-Patent Document 1).

  Status preventive maintenance, time-planned maintenance, and the like are implemented as preventive maintenance that prevents the occurrence of failures during the use of parts. Although state monitoring and maintenance is a technique that has attracted attention in recent years, a technique for predicting component failures is required. However, it is very difficult to predict failures individually for a plurality of parts in a complex system. Therefore, in the case of equipment including a plurality of parts, time-planned maintenance is often performed.

JP 2003-099119 A JP 2005-157793 A

Ben-Daya, Mohamed et al., “Maintenance, Modeling and Optimization”, Kluwer Academic Pub (ISBN 9780792379287), 2000

  Time-planned maintenance is a maintenance method for creating a part replacement plan based on the failure distribution of parts. This planning method is handled by a replacement problem in reliability engineering, and has traditionally been targeted at one part. However, in reality, replacement of a plurality of parts must be taken into account, and there is a problem in that the method of making an individual replacement plan is inefficient.

  Further, efficiency improvement in maintenance work is a problem for both maintenance contractors who perform maintenance and customers who perform maintenance. Maintenance contractors are seeking efficient maintenance that is as lean as possible. Customers also want to reduce maintenance costs and improve safety.

  There are various wastes in maintenance work, but here we focus on the dispatch of maintenance personnel especially in parts replacement. When there are a plurality of parts in the device to be maintained and each part is replaced independently, the minimum cost required for the dispatch of maintenance personnel is required each time the part is replaced. Therefore, if a plurality of parts can be replaced at the same time, the cost of maintenance personnel is required for one dispatch, but the total cost is smaller than when parts are replaced independently. It is expected. However, it is known that it is very difficult to create a maintenance plan considering simultaneous replacement of a plurality of parts.

  This invention is made in view of the above, Comprising: For the apparatus which has several components like a manufacturing apparatus or a large sized apparatus, the maintenance plan for maintaining each part efficiently can be created. It is an object to provide an apparatus and method that can be used.

  In order to solve the above-described problems and achieve the object, the present invention is a maintenance plan creation device that creates a maintenance plan that optimizes an expected cost that represents a cost required for replacement of each of a plurality of parts of equipment. For each of a plurality of reference periods serving as a reference for calculating a replacement period of the part, and for each part, a function determined for each of the parts that inputs the replacement period and outputs the expected cost , The replacement period represented by a multiple of the reference period, and each of the replacement periods before and after the replacement period outputting the minimum value of the expected cost is input and output from the function 2 A first calculation unit that calculates a minimization period representing the replacement period in which the smaller expected cost is output among the two expected costs, and the minimization period among a plurality of the reference periods is input to the function. Output part A second calculation unit that calculates an optimal reference period that represents the reference period that minimizes the sum of the expected cost for each and the maintenance staff cost required for replacement in the reference period; and And a creation unit that creates a maintenance plan that represents replacement with the minimization period calculated with respect to a reference period.

  The present invention is also a method that can be performed by the above apparatus.

  Advantageous Effects of Invention According to the present invention, there is an effect that a maintenance plan for efficiently maintaining each component can be created for a device having a plurality of components such as a manufacturing apparatus and a large-sized device.

FIG. 1 is a block diagram illustrating an example of the configuration of the maintenance plan creation apparatus according to the first embodiment. FIG. 2 is a diagram illustrating an example of a data structure of component information stored in the component information storage unit according to the first embodiment. FIG. 3 is a diagram illustrating an example of a data structure of data stored in the expected cost storage unit according to the first embodiment. FIG. 4 is a flowchart showing an overall flow of the maintenance plan creation process in the first embodiment. FIG. 5 is a flowchart showing the overall flow of expected cost optimization processing in the first embodiment. FIG. 6 is a diagram for explaining a specific example of the expected cost optimization process according to the first embodiment. FIG. 7 is a diagram for explaining a specific example of the expected cost optimization process according to the first embodiment. FIG. 8 is a diagram illustrating an example of a maintenance plan displayed in the first embodiment. FIG. 9 is a block diagram illustrating an example of the configuration of the maintenance plan creation apparatus according to the second embodiment. FIG. 10 is a diagram illustrating an example of a data structure of component information stored in the component information storage unit according to the second embodiment. FIG. 11 is a block diagram illustrating a detailed configuration of the function information output unit according to the second embodiment. FIG. 12 is a flowchart showing the overall flow of the maintenance plan creation process in the second embodiment. FIG. 13 is a diagram for describing a specific example of expected cost optimization processing according to the second embodiment. FIG. 14 is a diagram illustrating an example of a maintenance plan displayed in the second embodiment. FIG. 15 is a block diagram illustrating an example of the configuration of the maintenance plan creation device according to the third embodiment. FIG. 16 is a diagram illustrating an example of a data format of replacement history data stored in the history storage unit. FIG. 17 is a diagram illustrating an example of a data format of data stored in the replacement schedule storage unit. FIG. 18 is a block diagram illustrating a detailed configuration of the function information output unit according to the third embodiment. FIG. 19 is a flowchart showing the overall flow of the maintenance plan creation process in the third embodiment. FIG. 20 is a flowchart showing the overall flow of expected cost optimization processing in the third embodiment. FIG. 21 is a diagram for describing a specific example of the expected cost optimization process according to the third embodiment. FIG. 22 is a diagram illustrating an example of a maintenance plan displayed in the third embodiment. FIG. 23 is a block diagram illustrating an example of a configuration of a maintenance plan creation apparatus according to the fourth embodiment. FIG. 24 is a flowchart showing the overall flow of the maintenance plan creation process in the fourth embodiment. FIG. 25 is a graph showing an example of the relationship between the total cost, the number of times the maintenance staff is dispatched, and the lower limit of the number of dispatches. FIG. 26 is a diagram illustrating an example of a maintenance plan displayed in the modified example of the fourth embodiment. FIG. 27 is an explanatory diagram illustrating a hardware configuration of the maintenance plan creation device according to the first to fourth embodiments.

  Exemplary embodiments of a maintenance plan creation apparatus and method according to the present invention will be explained below in detail with reference to the accompanying drawings.

(First embodiment)
The maintenance plan creation apparatus according to the first embodiment first gives a reference period as a reference for calculating a part replacement interval (replacement period) as a fixed value, and takes a multiple of the given reference period. Among the replacement cycles, a replacement cycle (minimization cycle) that minimizes the expected cost required for replacement of the components and a multiple at that time are calculated for each component. Then, a reference period that minimizes the sum of expected costs calculated for each part and a multiple calculated for the reference period are obtained, and a maintenance plan for each part is created from the replacement period determined by the determined multiple. .

  FIG. 1 is a block diagram illustrating an example of the configuration of the maintenance plan creation apparatus 100 according to the first embodiment. As illustrated in FIG. 1, the maintenance plan creation apparatus 100 includes a parts information storage unit 161, an expected cost storage unit 162, an information reception unit 110, a function information output unit 120, an optimization unit 130, and a creation unit 140. And a display unit 150.

  The component information storage unit 161 stores component information, which is information for calculating costs required for component maintenance, for each component of the device to be maintained. FIG. 2 is a diagram illustrating an example of a data structure of component information stored in the component information storage unit 161. As shown in FIG. 2, the component information includes an address ID, a machine ID, a component ID, a price, a failure loss, and maintenance personnel costs.

  The address ID is information for identifying the address of the place where the device is installed. The machine ID is information for identifying each machine (device). In the present embodiment, input of address information including an address ID is received, and a maintenance plan for each part included in each device corresponding to the address ID of the received address information is created.

  The component ID is information for identifying each component included in the device having the machine ID. The price represents the price of the component with the component ID. Failure loss represents the amount of loss caused by component failure. The maintenance staff cost represents the cost of the maintenance staff who replaces the part with the part ID at the address of the address ID. The maintenance staff cost is a common value for each part for each address. Therefore, you may comprise so that the maintenance worker expense for every address ID may be preserve | saved in an independent table.

  The data structure of the component information as shown in the figure is an example, and component information of another data structure may be used. For example, if the cost for each address is not different, it is possible to accept the input of the machine ID without using the address ID and create a maintenance plan for each part included in each device of the received machine ID. Good.

  The expected cost storage unit 162 stores the expected cost for each part calculated by the optimization unit 130. FIG. 3 is a diagram illustrating an example of a data structure of data stored in the expected cost storage unit 162. As shown in FIG. 3, the expected cost storage unit 162 is the sum of the maintenance staff cost, the multiple cycle number of each part and the local optimum cost, the maintenance staff cost and the local optimum cost of each part for each reference period. The total costs are stored in association with each other.

  The local optimum cost represents the minimum expected cost for each part calculated by the optimization unit 130. The multiple period number is a positive integer representing how many times the replacement period (minimization period) giving the local optimum cost is the reference period. That is, the value obtained by dividing the minimization period by the reference period corresponds to the multiple period number.

  The expected cost storage unit 162 temporarily stores the sum of expenses calculated for each reference period, and is referred to in order to obtain a reference period (optimum reference period) that minimizes the total cost. The component information storage unit 161 and the expected cost storage unit 162 are configured by any commonly used storage medium such as an HDD (Hard Disk Drive), an optical disk, a memory card, and a RAM (Random Access Memory). be able to.

  The information receiving unit 110 receives input of address information including an address ID for identifying an address of a place where a device for creating a maintenance plan is installed.

The function information output unit 120 outputs a function for calculating the expected cost per unit time of each component. Specifically, the function information output unit 120 first specifies each component k (1 ≦ k ≦ K, where K is the number of components) of the device installed at the address of the address ID included in the received address information. . Then, the function information output unit 120 outputs an expected cost C _k (t) that is a predetermined function for calculating the expected cost for each component k. Note that t represents an elapsed time from a reference date and time that is a reference for creating a maintenance plan.

  The optimization unit 130, based on the function output by the function information output unit 120, a reference period (optimum reference period) that minimizes the sum of expenses (sum of expenses) necessary for replacing each component k. Then, an optimum multiple cycle number representing the multiple cycle number of each component with respect to the optimum reference cycle is obtained.

Optimization unit 130 represents first cost sum _C of more parts in consideration of simultaneous replacement _{(T, n 1, n 2} , ···, n K) of the following formula (1). T represents a reference period (positive real number), _nk represents a multiple period number of each component k, and z represents a maintenance staff cost. Then, the optimization unit 130 obtains an optimum reference period T ^* representing a reference period that minimizes the total cost C (T, n ₁ , n ₂ ,..., N _K ) according to the following equation (2): An optimum multiple cycle number n ^* _k (1 ≦ k ≦ K) representing the multiple cycle number of each component k with respect to the optimum reference cycle T ^* is calculated.

  The maintenance staff cost z represents a maintenance staff cost common to each part stored in the part information storage unit 161. The total cost is calculated by adding a value (z / T) obtained by dividing the maintenance worker cost z by the reference period T to the expected cost of each component.

In this way, the total cost, which is the sum of the expected cost of each part and the cost of maintenance personnel in consideration of simultaneous replacement, is a reference period T common to each part and a positive integer n _k indicating at which point Represented by Therefore, the cost summation optimization problem is a mixed integer programming problem in which a reference period that is a positive continuous variable and a multiple period number that is a positive integer are variables. In general, it is difficult to find a global optimal solution for a mixed integer programming problem. However, in the present embodiment, it is possible to search for a global optimum solution by the following procedure.

That is, in the present embodiment, for an optimization problem in which continuous variables and positive integers are mixed, a positive integer n _k that minimizes the expected cost is obtained by first giving a reference period that is a continuous variable as a fixed value. Into a subproblem to search. If the reference period T, which is a positive continuous variable, is fixed, the problem of searching for a positive integer _nk is a time interval that is a multiple of the reference period T, and is one of two time intervals that sandwich an optimal time interval. Choosing a time interval that has a small expected cost becomes a problem. This time interval can be determined independently for each component, and the amount of calculation is only about the power of the total number of components, so that the algorithm is capable of actual calculation.

Note that the optimum time interval represents a time interval at which the expected cost is minimum among time intervals representing elapsed time from the reference date and time. Hereinafter, this time interval is referred to as an optimal replacement period t ^* _k . The optimum replacement period can be obtained as a time interval that gives the minimum value of the function output by the function information output unit 120, for example.

  In the case of a function having a large number of general minimal solutions, unless the existence range of the minimal solution is known, a candidate having the minimum expected cost in an infinite range must be searched. However, the present embodiment can limit the number of solution candidates to two by taking advantage of the fact that the expected cost function has at most one minimum value in a finite interval.

  Next, a detailed configuration of the optimization unit 130 will be described. The optimization unit 130 includes an initialization unit 131, a first calculation unit 132, a storage unit 133, and a second calculation unit 134.

The initialization unit 131 initializes various variables used in the calculation by the optimization unit 130. For example, the initialization unit 131 initializes the reference period T to the initial value T _initial . Further, the initialization unit 131 sets a step size ΔT for updating the reference period T and a maximum value T _max of the reference period T. As the initial value T _initial , the step size ΔT, and the maximum value T _max , preset values are used. In addition, you may comprise so that the value of these variables can be input from the exterior of an apparatus.

The initial value T _initial may be a positive real number, but may be set to 0 when searching for a solution in the entire region of the reference period. When searching for a solution only in a specific region, the lower limit of the region may be set to the initial value T _initial . If the step size ΔT is set to a smaller value, the solution can be searched in detail. However, in reality, the minimum unit (for example, one day or one hour) necessary for the plan may be set. The maximum value T _max may be a sufficiently large value, but in reality, the maximum value of the optimum replacement periods of a plurality of components may be given.

The first calculation unit 132 calculates, for each of the plurality of reference periods T, a replacement period (minimization period) that minimizes the expected cost of each component among replacement periods that are multiples of the reference period T. . The first calculation unit 132 first sequentially calculates the reference period T that is increased by the increment ΔT from the initial value T _initial to the maximum value T _max . The first calculating unit 132 is a replacement period that is a multiple of the reference period T with respect to each calculated reference period T, and is an optimal replacement period t ^* _{k of the} component k (1 ≦ k ≦ K). Among the two replacement cycles sandwiching, a replacement cycle with a small expected cost is obtained.

Specifically, the first calculation unit 132 sets the time intervals (replacement periods) satisfying l _k (T) ≦ t ^* _k ≦ u _k (T) to l _k (T) and u _k (T). Among them, a replacement cycle with a small expected cost is selected as a minimization cycle. Hereinafter, l _k (T) and u _k (T) are referred to as a left end point and a right end point, respectively. The left end point and the right end point correspond to a replacement period that is a multiple of the reference period T before and after the optimum replacement period, respectively. When the reference period T is fixed, the left end point l _k (T) and the right end point u _k (T) are expressed by the following equations (3) using the optimum replacement period t ^* _k and the ceiling function, respectively. And (4). Equation (5) represents the definition of the ceiling function used in equations (3) and (4).

Thus, if T is Sadamare _l k (T) and _u k (T) can be easily calculated. Further, the expected cost C _k (t) of each component k used in the above equation (1) can be obtained from the function information output unit 120. For this reason, the first calculation unit 132 selects a smaller one of C _k (l _k (T)) and C _k (u _k (T)) as a local value that is the minimum value of the expected cost of each component with respect to the reference period T. It can be calculated as the optimal cost. Further, the first calculation unit 132 can calculate the number of multiple cycles in the reference cycle T by dividing the minimization cycle by the reference cycle T.

Specifically, the first calculation unit 132 calculates the local optimum cost C _k (n _k T) of each component k by the following equation (6). In addition, the first calculation unit 132 calculates the multiple cycle number _nk by the following equation (7).

  In this way, the first calculation unit 132 calculates the local optimum cost and the multiple cycle number for each component, and delivers the local optimum cost and the multiple cycle number of each component in the reference cycle T to the storage unit 133.

  The storage unit 133 stores the expected cost by associating the reference period T, the maintenance worker cost for the reference period T, the local optimum cost and multiple period number of each component calculated by the first calculation unit 132, and the total cost. Stored in the unit 162.

  The maintenance staff cost for the reference period T is obtained by dividing the maintenance staff cost stored in the component information storage unit 161 by the reference period T. Further, the total cost is obtained by adding the maintenance staff cost and the local optimum cost of each part (the above formula (1)).

The second calculation unit 134 calculates an optimal reference cycle T ^* , which is a reference cycle that gives the minimum total cost among the total costs for each reference cycle stored in the expected cost storage unit 162, using the following equation (8). To do.

The total cost C (T, n ₁ , n ₂ ,..., N _K ) included in the right side is stored in the expected cost storage unit 162. The second calculation unit 134 searches for the smallest value among the cost sum values for each reference cycle, and sets the reference cycle corresponding to the searched cost sum as the optimum reference cycle T ^* .

  The second calculation unit 134 includes an optimum reference period, an optimum multiple period number representing the multiple period number of each component calculated with respect to the optimum reference period, and an optimum cost representing the total cost calculated with respect to the optimum reference period. The sum is passed to the creation unit 140.

  The creation unit 140 creates a maintenance plan for each component based on the information passed from the second calculation unit 134. For example, the creation unit 140 creates a maintenance plan for each part, indicating that the parts are to be replaced on the day after the replacement period represented by the optimum multiple period times the optimum reference period from the reference date and time. That is, the creation unit 140 obtains a scheduled part replacement date in real time based on the reference date and time and the replacement cycle, and creates a maintenance plan representing replacement on the scheduled part replacement date. The creation unit 140 creates a maintenance plan in which a plurality of parts having the same optimal multiple cycle number are always replaced at the same timing. A collection of parts having the same optimum multiple period number is called a same period cluster.

  The display unit 150 is a display device such as a display that displays the maintenance plan created by the creation unit 140. It is not necessary to display the maintenance plan. For example, the created maintenance plan may be printed by a printer. Moreover, you may comprise so that a maintenance plan may be output to an external information processing apparatus (not shown).

  Next, a maintenance plan creation process by the maintenance plan creation device 100 according to the first embodiment configured as described above will be described with reference to FIG. FIG. 4 is a flowchart showing an overall flow of the maintenance plan creation process in the first embodiment.

First, the information reception part 110 receives the input of address information including address ID (step S401). Next, the function information output unit 120 outputs an expected cost calculation function C _k (t) for each component k of the device installed at the address of the address ID included in the address information (step S402).

Next, based on the output function C _k (t), the optimization unit 130 minimizes the sum of expected costs of each component of the device at the address, and the optimal multiple period Expected cost optimization processing for calculating several times is executed (step S403). Details of the expected cost optimization process will be described later.

  Next, the creation unit 140 creates a maintenance plan that optimizes the expected cost for each part (step S404). Specifically, the creation unit 140 creates a maintenance plan for replacement of each part on the day after the replacement period, which is represented by the optimum multiple of the optimum reference period. Next, the display unit 150 displays the created maintenance plan (step S405) and ends the maintenance plan creation process.

  Next, details of the expected cost optimization process in step S403 will be described with reference to FIG. FIG. 5 is a flowchart showing the overall flow of expected cost optimization processing in the first embodiment.

First, the optimization unit 130 receives the expected cost C _k (t) for each part output by the function information output unit 120 (step S501). Next, the optimization unit 130 selects an unprocessed part among the parts included in the device for creating the maintenance plan (step S502). Next, the initialization unit 131, a reference period T is initialized to the initial value T _initial (step S503).

  Next, the first calculation unit 132 updates the reference period T by adding the step size ΔT (step S504). Note that the step size ΔT may not be added in the first process (immediately after the initialization of the reference period T).

  Next, the first calculator 132 calculates an optimal replacement period from the accepted function (step S505). In addition, you may comprise so that the optimal replacement period calculated beforehand may be input from the function information output part 120, for example.

  Next, the first calculator 132 selects, as the minimization period, an end point with a small expected cost among the left end point and the right end point, which are replacement periods that are multiples of the reference period T before and after the optimal replacement period (step S506). ). Next, the first calculation unit 132 calculates the number of multiple cycles of the part by dividing the minimization cycle by the reference cycle T (step S507).

  Next, the storage unit 133 stores the calculated multiple cycle number and the local optimum cost that is the expected cost corresponding to the minimization cycle in the expected cost storage unit 162 in association with the current reference cycle T ( Step S508).

Then, the first calculator 132, the reference period T is determined whether or not the maximum value _{T max} is less than (step S509). If it is smaller (step S509: YES), the first calculation unit 132 repeats the process by adding the increment ΔT to the reference period T (step S504).

When the reference period T is equal to or greater than the maximum value _Tmax (step S509: NO), the first calculation unit 132 determines whether all parts have been processed (step S510). When all the parts have not been processed (step S510: NO), the first calculation unit 132 selects the next unprocessed part and repeats the process (step S502).

When all the parts have been processed (step S510: YES), the second calculation unit 134 refers to the expected cost storage unit 162, and among the reference cycles T, the optimum reference cycle T that is the reference cycle that minimizes the total cost. ^* Is calculated (step S511), and the expected cost optimization process is terminated.

  Next, a specific example of the expected cost optimization process will be described with reference to FIGS. 6 and 7 are diagrams for explaining a specific example of the expected cost optimization process according to the first embodiment.

A thin solid line 601 in each figure represents a maintenance staff cost (z / T) obtained by dividing a maintenance staff cost z common to a certain part by a reference period T. A dotted line 602 in each figure represents an expected cost C _k (t) of the part. Point 611 represents the point corresponding to the minimum value of the expected cost _C k (t). The optimum replacement period t ^* _k , which is the replacement period corresponding to this minimum point, is about 203 in the example of FIG.

FIG. 6 shows an example when the reference period T = 60. For this reason, the expected costs in the replacement periods 180 and 240 that are multiples of the reference period T = 60 sandwiching the optimal replacement period t ^* _k are compared, and the smaller one is selected. In the figure, the replacement period 180 corresponding to the point 612 that is the left end point is selected. The number of multiple cycles at this time is 3 (= 180/60). A thick solid line 603 in the figure represents a change in the sum of the maintenance staff cost (z / T) and the local optimum cost with respect to the reference period T. In the reference period T = 60, the maintenance staff cost (z / T) is added to the expected cost at the point 612 (local optimum cost).

FIG. 7 shows an example when the reference period T = 80. In this example, by comparing the expected cost at the optimum replacement period t ^* _k ≒ 203 replacement period 160 and 240 is a multiple of the reference period T = 80 sandwiching, and selects the smaller. In the figure, the replacement period 240 corresponding to the point 712 which is the right end point is selected. The number of multiple cycles at this time is 3 (= 240/80). A thick solid line 703 in the drawing represents a change in the sum of the maintenance staff cost (z / T) and the local optimum cost with respect to the reference period T.

  As described above, if the formula of the function for calculating the expected cost and the optimum replacement period are known, the optimum multiple period number can be uniquely determined when the reference period is fixed.

  Next, a specific example of the maintenance plan will be described with reference to FIG. FIG. 8 is a diagram illustrating an example of a maintenance plan displayed in the first embodiment. The display unit 150 displays the maintenance plan created by the creation unit 140 in real time. The creation unit 140 obtains a scheduled replacement date in real time based on the optimum reference cycle output from the optimization unit 130 and the multiple cycle number of each component. The creation unit 140, for example, takes the date and time when the maintenance plan creation device 100 is introduced as the reference date and the real time as the date when the period obtained by multiplying the optimum reference period by the multiple period number has elapsed from the reference date and time. Ask for replacement date.

  6 and 7 display the maintenance plan when the reference date and time is set to 0. By converting the reference date and time into a date display, a maintenance plan in real time as shown in FIG. 8 can be created. . FIG. 8 shows an example when the reference period is 30 days. This figure shows an example in which a maintenance plan indicating that a part (part a) is replaced every 30 days and another part (part b) is replaced every 60 days is displayed on a calendar. In the same figure, the reference period and the total cost are also displayed.

  As described above, in the maintenance plan creation device according to the first exemplary embodiment, the minimum period in which the expected cost is minimized among the replacement periods that are multiples of the reference period given as a fixed value, the multiples at that time, And calculate the expected cost for each part, find the reference period that minimizes the sum of the expected cost for each part, and create a maintenance plan for each part from the replacement period determined by the multiple calculated for that reference period be able to.

  This makes it possible to create a maintenance plan that considers simultaneous replacements that could not be handled by conventional replacement plans. That is, the maintenance staff can always replace a predetermined group of parts at a constant cycle. If the parts group can be collected in this way, the maintenance work can be simplified and made more efficient.

(Second Embodiment)
The function for calculating the expected cost used in the first embodiment can be generally derived using a failure distribution. The derivation method differs depending on the maintenance method. As typical methods for time-planned maintenance, periodic maintenance (block replacement) and time-dependent maintenance (age replacement) are known.

  In periodic maintenance, parts are replaced at regular replacement times. In periodic maintenance, it is relatively easy to consider simultaneous replacement. In addition, unlike the age replacement described later, the initial plan created first is permanently performed. Therefore, the expected cost can be easily calculated and the cost can be estimated easily. However, if the start of use of each part is different, a plan cannot be created by periodic maintenance. A plan can be created immediately after all parts have been replaced at once (immediately after overhaul). Furthermore, since replacement is executed at the same cycle, compatibility with other similar periodic maintenance plans is good. This is also a measure that makes it easy to consider the leveling of required personnel when planning personnel allocation.

  Temporary maintenance is a measure for executing the next replacement from the present time. In maintenance over time, the initial plan is permanently executed if no failure occurs. However, if a failure occurs, replanning must be performed when the failure occurs. Temporary maintenance can be applied even when the start of use of each part is different, but it is generally difficult to consider simultaneous replacement.

  If the method of the first embodiment is applied at the time of equipment introduction, periodic maintenance can be executed. In the second embodiment, a specific method for performing regular maintenance (block replacement) will be described. A specific example of performing maintenance over time (age replacement) will be described in the third embodiment.

  In block replacement, periodic replacement times t, 2t, 3t,... Are determined, and parts are replaced at the replacement time. Even if a failure occurs immediately before the regular replacement time and the parts have been replaced at that time, the replacement is executed at the regular replacement time immediately after the failure. Thus, when a failure occurs just before the regular replacement time, the cost may increase because parts are replaced even if they are almost new. However, the replacement plan does not always change, so the plan is robust.

  FIG. 9 is a block diagram illustrating an example of the configuration of the maintenance plan creation device 200 according to the second exemplary embodiment. As illustrated in FIG. 9, the maintenance plan creation device 200 includes a parts information storage unit 261, an expected cost storage unit 162, an information reception unit 110, a function information output unit 220, an optimization unit 130, and a creation unit 140. And a display unit 150.

  In the second embodiment, the data structure of the component information storage unit 261 and the function of the function information output unit 220 are different from those of the first embodiment. Other configurations and functions are the same as those in FIG. 1 which is a block diagram showing the configuration of the maintenance plan creation device 100 according to the first exemplary embodiment, and thus the same reference numerals are given and description thereof is omitted here.

  The component information storage unit 261 is different from the component information storage unit 161 of the first embodiment in that it stores component information further including information for determining a function of expected cost. FIG. 10 is a diagram illustrating an example of a data structure of component information stored in the component information storage unit 261. As shown in FIG. 10, in addition to the address ID, the machine ID, the part ID, the price, the failure loss, and the maintenance staff cost, the component information includes a failure distribution, a shape parameter, and a scale parameter. Is included.

  In the fault distribution, information specifying the type of fault distribution of each component is set. The figure shows an example in which information indicating that the failure distribution is a Weibull distribution is set. A failure distribution other than the Weibull distribution may be set.

  As the shape parameter, a parameter for determining the shape of the failure distribution is set. The scale parameter sets a parameter that determines the scale of the failure distribution. Note that these parameters are examples, and parameters that determine the shape of the failure distribution and the like may be stored in accordance with the type of failure distribution.

The function information output unit 220 outputs the expected cost C _k (t) of the following equation (9), which is a function for calculating the expected cost for each component k in the case of block replacement. Here, g _k is a failure loss, q _k is a part price, and z is a maintenance staff cost. These are coefficients given in advance, and can be acquired from the component information storage unit 261, for example. M _k (t) represents a regeneration function for calculating an expected value of the number of failures of the component k occurring from time 0 to t.

  FIG. 11 is a block diagram illustrating a detailed configuration of the function information output unit 220. As shown in FIG. 11, the function information output unit 220 includes a reproduction function calculation unit 221 and an expected cost function calculation unit 222.

The reproduction function calculation unit 221 calculates a reproduction function M _k (t) for each component k. The reproduction function M _k (t) is expressed by the following equation (10). Here, n is the number of failures, P [N (t) = n] is the probability of failure occurring n times by time t, and F _k (t) is the failure distribution of the component k. The failure distribution is a distribution that represents the probability that the component k will fail by time 0 to t. The failure distribution F _k (t) can be determined by the shape parameter, the scale parameter, and the like of the component information storage unit 261.

The reproduction function M _k (t) can be obtained by, for example, the following expressions (11) to (12).

That is, first, Laplace-Stilches transformation of the failure distribution is performed by the equation (11) to obtain F ^* _k (s). Then, M ^* _k (s) is calculated by substituting F ^* _k (s) into equation (12). Finally, M ^* _k (s) is subjected to inverse Laplace-Stilches transform to calculate a reproduction function M _k (t). However, in most failure distributions, it is difficult to calculate the Laplace-Stilches transform.

For this reason, the replay function calculation unit 221 performs Ozbaykal (T. Ozbaykal, “Bounds and approximations of the renewal function”, unpublished MS thesis, Naval Postgraduate School, Department shown in the following equations (13) to (15). The approximate reproduction function is calculated using the approximation formula of Operations Research and Administrative Science, Monterey, California, 1971).

The expected cost function calculation unit 222 calculates the expected cost C _k (t) by substituting the regeneration function M _k (t) calculated in this way into the equation (9).

  Note that the optimization problem of the total cost in the case of one part is a problem of searching for a replacement period t at which the expected cost is minimized with the replacement period t as a continuous variable. That is, if a function of expected cost is given, a replacement period t (optimal replacement period) that minimizes the expected cost can be obtained by a Newton method, downhill simplex method, or the like, which is a one-variable function optimization method. . Generally, the optimal replacement period in the replacement problem exists in a finite number or becomes infinite. When the optimum replacement period is infinite, it means that it is sufficient to replace parts when a failure occurs, and it is not necessary to replace them periodically. In other words, this means that post-maintenance is the most appropriate measure than preventive maintenance. Accordingly, a part whose optimum replacement period of expected cost given by equation (9) is infinite is not included in the maintenance plan because it has no meaning to perform preventive maintenance.

  Next, a maintenance plan creation process performed by the maintenance plan creation device 200 according to the second embodiment configured as described above will be described with reference to FIG. FIG. 12 is a flowchart showing the overall flow of the maintenance plan creation process in the second embodiment.

First, the information receiving unit 110 receives input of address information including an address ID (step S1201). Next, the reproduction function calculation unit 221 of the function information output unit 220 calculates a reproduction function M _k (t) for each component k of the device installed at the address with the address ID included in the address information (step S1202).

Next, the expected cost function calculation unit 222 of the function information output unit 220 calculates the expected cost C _k (t) by substituting the calculated reproduction function M _k (t) into the equation (9), and is optimal. It outputs to the conversion unit 130 (step S1203).

  The expected cost optimization process, the maintenance plan creation process, and the maintenance plan display process from step S1204 to step S1206 are the same as the process from step S403 to step S405 in the maintenance plan creation apparatus 100 according to the first embodiment. Therefore, the explanation is omitted.

  Next, a specific example of the expected cost optimization process will be described with reference to FIG. FIG. 13 is a diagram for describing a specific example of expected cost optimization processing according to the second embodiment. The figure shows an example of a replacement timing for optimizing the expected cost when the parts a, b, and c are newly used at the same time. The figure shows an example in the case of the reference period T = 124. In this example, it is shown that the parts a and b are always replaced at the same time in the optimum reference period, and the part c is replaced at a period twice the optimum reference period (lower part of the figure).

  Next, a specific example of the maintenance plan will be described with reference to FIG. FIG. 14 is a diagram illustrating an example of a maintenance plan displayed in the second embodiment. This figure shows an example of a maintenance plan indicating that a device including parts a, b, and c is replaced at the same replacement timing as in FIG.

  As described above, in the maintenance plan creation device according to the second embodiment, when the periodic maintenance (block replacement) method is used, simultaneous replacement of a plurality of parts is performed by the same method as in the first embodiment. It is possible to create a maintenance plan in consideration.

(Third embodiment)
The periodic maintenance (block replacement) method as in the second embodiment cannot be applied to devices that are already in operation. Therefore, in the third embodiment, a maintenance plan is created by the same technique as in the first embodiment for devices and equipment that are already in operation by the maintenance over time (age replacement) method.

  As described above, age replacement is a model in which a period t representing an elapsed time from the start of use is determined, and the part is replaced when the period t elapses or a failure occurs. In the case of age replacement, if a component fails before the period t has elapsed, it is necessary to keep a history of the date and time when the component was replaced. In age replacement, new parts are not replaced immediately. However, since the plan is changed each time a failure occurs, it is not suitable for creating a replacement plan for a long period in the future.

  FIG. 15 is a block diagram illustrating an example of a configuration of the maintenance plan creation device 300 according to the third exemplary embodiment. As illustrated in FIG. 15, the maintenance plan creation apparatus 300 includes a parts information storage unit 261, an expected cost storage unit 162, a history storage unit 363, a replacement schedule storage unit 364, an information reception unit 110, and function information. An output unit 320, an optimization unit 330, a creation unit 140, and a display unit 150 are provided.

  In the third embodiment, the addition of the history storage unit 363 and the replacement schedule storage unit 364 and the functions of the function information output unit 320, the first calculation unit 332, and the second calculation unit 334 are the second. This is different from the embodiment. Other configurations and functions are the same as those in FIG. 9, which is a block diagram showing the configuration of the maintenance plan creation device 200 according to the second embodiment, and thus the same reference numerals are given and description thereof is omitted here.

  The history storage unit 363 stores replacement history data representing the history of replacement date and time for each component. FIG. 16 is a diagram illustrating an example of a data format of replacement history data stored in the history storage unit 363. As illustrated in FIG. 16, the history storage unit 363 stores replacement history data in which an address ID, a machine ID, a component ID, and a replacement date / time are associated with each other. In the replacement date and time, the date and time when the part was replaced in the past is sequentially stored.

  Returning to FIG. 15, the replacement schedule storage unit 364 stores the scheduled replacement date calculated for each component. FIG. 17 is a diagram illustrating an example of a data format of data stored in the replacement schedule storage unit 364. As illustrated in FIG. 17, the replacement schedule storage unit 364 stores data in which an address ID, a machine ID, a component ID, and a scheduled replacement date are associated with each other. In the scheduled replacement date, the latest replacement date among the replacement dates in the history storage unit 363 is set as an initial value. Thereafter, the next scheduled replacement date calculated by the optimization unit 330 is sequentially stored in the replacement schedule storage unit 364.

The function information output unit 320 outputs the expected cost C _k (t) of the following equation (16), which is a function for calculating the expected cost for each part k in the case of age replacement. Here, g _k is a failure loss, q _k is a part price, z is a maintenance staff cost, F _k (t) is a failure distribution of the part k, and R _k (t) is a reliability function. The reliability function R _k (t) represents the probability that the component k will not fail for more than t hours from time 0, and satisfies the relationship of R _k (t) = 1−F _k (t).

  FIG. 18 is a block diagram illustrating a detailed configuration of the function information output unit 320. As illustrated in FIG. 18, the function information output unit 320 includes an integral calculation unit 321 and an expected cost function calculation unit 322.

The integral calculation unit 321 calculates the integral of the reliability function included in the denominator of the above equation (16). The expected cost function calculation unit 322 calculates the expected cost C _k (t) by substituting the integral of the reliability function calculated by the integration calculation unit 321 into the equation (16).

  Returning to FIG. 15, the first calculation unit 332 refers to the replacement history data, and calculates the minimization period at which the expected cost of each component is minimized, in the first and second embodiments. This is different from the calculation unit 132.

The first calculation unit 332 refers to the replacement history data in the history storage unit 363, reads the most recent replacement date and time of each component, and stores it in the replacement schedule storage unit 364 as the initial value of the scheduled replacement date. Hereinafter, the most recent replacement date and time for the component k is T ⁰ _k .

Optimization unit 330, like the first embodiment, to determine the optimal replacement period from a certain reference date and time (hereinafter referred to as T ^b). A third embodiment for applying age replacement, instead of calculating the cost sum of the first embodiment (1) of _{C k (n k T),} C k (n k T + δT k ) Is used to calculate the total cost according to the following equation (17).

Here, δT _k is the difference between the reference date and time T ^b and the latest replacement date and time T ⁰ _k of the component k (δT _k --- = T ^b −T ⁰ _k ). Since the creation of the maintenance plan is to determine the date and time when the next replacement is executed with respect to the replacement performed in the past, δT _k ≧ 0 always holds. At this time, if the optimum reference period ^{T *} and the optimum multiple periodicity ⁿ _{* k} of each part is obtained, the next replacement date ^T _{1 k} of component k ^{_{is, T 1 k = T b +}} n * k T ^* Here, T ¹ _k represents the date and time when the part k is replaced for the first time after the reference date and time T ^b . The expected cost on the scheduled replacement date is C (T ¹ _k −T ⁰ _k ) = C (T ^b + n ^* _k T ^* −T ⁰ _k ). Actually, only the component having the smallest optimum multiple cycle number is replaced, and a new maintenance plan is created with T ^b + n ^* _k T ^* as a new reference date T ^b . Furthermore, if T ¹ _k is generalized, the date and time when the component k is replaced x-th after the reference date and time T ^b becomes T ^x _k .

When the x-th scheduled replacement date T ^x _k is obtained, the second calculation unit 334 sequentially stores the planned replacement date T ^x _k in the replacement schedule storage unit 364. Then, the second calculation unit 334 determines whether or not the interval (optimum reference period) for the scheduled replacement date has converged to a constant value. Specifically, the second calculation unit 334 determines whether T ^x _k −T ^x−1 _k ≠ T ^x−1 _k −T ^x−2 _k is true or false. If true, the interval has not converged, and the process is repeated to calculate the next scheduled replacement date. If false, the interval has converged, so the process ends. Thereby, it is possible to create a maintenance plan representing replacement at a converged interval. That is, even with age replacement, it is possible to create a maintenance plan that is periodically replaced as in the second embodiment.

The optimal reference period when the converged ^{T *,} the optimum multiple number of cycles of the component k and _{^{n * k, T x k -T}} x-1 k = n * k T * is satisfied. In the transient state, since the total cost changes every replacement, the first calculation unit 332 substitutes the optimum reference period T ^* and the optimum multiple period number n ^* _k after convergence into the above equation (16), Calculate the expected cost after convergence.

However, in the case of age replacement it is necessary to perform re-planning if a failure occurs, if there part j has caused the failure to date T _j, the time T _j as a new reference time T _b, series Will be repeated.

  Next, a maintenance plan creation process performed by the maintenance plan creation apparatus 300 according to the third embodiment configured as described above will be described with reference to FIG. FIG. 19 is a flowchart showing the overall flow of the maintenance plan creation process in the third embodiment.

First, the information reception part 110 receives the input of address information including address ID (step S1901). Next, the integral calculation unit 321 of the function information output unit 320 calculates the integral of the reliability function R _k (t) for each component k of the device installed at the address with the address ID included in the address information (step S1902). ).

Next, the expected cost function calculation unit 322 of the function information output unit 320 calculates the expected cost C _k (t) by substituting the calculated integral into the equation (16), and outputs it to the optimization unit 330. (Step S1903).

Next, the optimization unit 330, based on the outputted function C _{k (t),} to perform the expected cost optimization process with reference to the replacement history data (step S1904). Details of the expected cost optimization process of the third embodiment will be described later.

  The maintenance plan creation process and the maintenance plan display process from step S1905 to step S1906 are the same as the process from step S404 to step S405 in the maintenance plan creation apparatus 100 according to the first embodiment, and thus description thereof is omitted. To do.

  Next, details of the expected cost optimization process in step S1904 will be described with reference to FIG. FIG. 20 is a flowchart showing the overall flow of expected cost optimization processing in the third embodiment.

First, the first calculation unit 332 of the optimization unit 330 reads the latest replacement date and time of each part from the replacement history data of the history storage unit 363, and stores the replacement schedule as an initial value T ⁰ _k on the scheduled replacement date. The data is stored in the unit 364 (step S2001).

  The processing from step S2002 to step S2012 is the same as the processing from step S501 to step S511 in the maintenance plan creation device 100 according to the first embodiment, and thus the description thereof is omitted.

However, in this embodiment, obtains the? T _k is the difference between the reference time ^{T b} and replacement Date ^T _{x k} as described _above, instead of the _{C k (n k T),} C k (n k T + δT It differs from the first embodiment in that the optimum reference period and the optimum multiple period number are calculated using _k ).

After calculating the optimum reference period in step S2012, the second calculation unit 334 determines whether or not the optimum reference period has converged to a constant value (step S2013). For example, the second calculation unit 334 determines the convergence of the optimum reference period by determining whether T ^x _k −T ^x−1 _k ≠ T ^x−1 _k −T ^x−2 _k as described above. To do.

When the optimal reference period has not converged to a constant value (step S2013: NO), the second calculation unit 334 sets the next scheduled replacement date as a new reference date (step S2014). Then, it returns to step S2003 and a process is repeated. The next scheduled replacement date can be calculated by adding the product of the optimum reference period T ^* and the optimum multiple period number n ^* _k to the current reference date and time.

  When the optimum reference period converges to a constant value (step S2013: YES), the second calculation unit 334 outputs the converged optimum reference period and the corresponding optimum multiple period number, and ends the expected cost optimization process.

  Next, a specific example of the expected cost optimization process will be described with reference to FIG. FIG. 21 is a diagram for describing a specific example of the expected cost optimization process according to the third embodiment.

  This figure shows an example when the replacement of the component a is executed at a certain time t. The graph on the upper left of the figure represents a maintenance plan created by replacing the age with time t as the reference date. This figure shows that in this case, a solution has been obtained that the part d is also replaced at time t. Then, in a situation where the parts a and d are exchanged at the time t, a maintenance plan is created again with the time t as the reference date and time by age exchange. The graph in the upper right of the figure shows the maintenance plan created at this time. The upper right graph shows that a solution that all parts a to d are replaced 158 after time t is obtained. A maintenance plan at time t is created by repeating such processing.

  Next, a specific example of the maintenance plan will be described with reference to FIG. FIG. 22 is a diagram illustrating an example of a maintenance plan displayed in the third embodiment. The figure shows an example of a maintenance plan created with a certain point in time as a reference date. This maintenance plan is updated each time a failure occurs.

  As described above, in the maintenance plan creation apparatus according to the third embodiment, when the time-dependent maintenance (age replacement) method is used, simultaneous replacement of a plurality of parts is performed by the same method as in the first embodiment. It is possible to create a maintenance plan in consideration.

(Fourth embodiment)
In age replacement as in the third embodiment, the maintenance plan is changed every time a failure occurs, so it is difficult to estimate the number of times the maintenance staff is dispatched. However, in the case of block replacement as in the second embodiment, the number of dispatches of maintenance personnel can be estimated. The maintenance plan creation apparatus according to the fourth embodiment estimates the number of dispatches of maintenance personnel, and determines from the number of dispatches whether the created maintenance plan is feasible.

  FIG. 23 is a block diagram illustrating an example of the configuration of the maintenance plan creation apparatus 400 according to the fourth embodiment. As shown in FIG. 23, the maintenance plan creation apparatus 400 includes a parts information storage unit 261, an expected cost storage unit 162, an information reception unit 410, a function information output unit 220, an optimization unit 430, and a creation unit 140. And a display unit 150.

  The fourth embodiment is different from the second embodiment in that the function of the information reception unit 410 and the addition of the third calculation unit 435 to the optimization unit 430 are added. Other configurations and functions are the same as those in FIG. 9, which is a block diagram showing the configuration of the maintenance plan creation device 200 according to the second embodiment, and thus the same reference numerals are given and description thereof is omitted here.

  The information receiving unit 410 is different from the information receiving unit 110 of the second embodiment in that it further receives an input of maintenance personnel information that is information regarding maintenance personnel. The maintenance staff information includes the number N of maintenance staffs and a paging limit p. The dispatchable limit p represents the upper limit of the number of dispatchable times per maintenance staff. In addition, you may comprise so that the maintenance personnel number N and the possible dispatch limit p may be hold | maintained inside an apparatus.

The third calculation unit 435 calculates the number of dispatches of maintenance personnel when parts are replaced at a minimization cycle, and determines whether a maintenance plan based on the calculated number of dispatches can be realized based on the maintenance personnel information. Specifically, the third calculation unit 435 calculates the number of times N _b (T, n ₁ , n ₂ ,..., N _K ) of maintenance personnel in the case of block replacement by the following equation (18). calculate.

Generally, the number of dispatches of maintenance personnel converges to a finite value at the limit where T is infinite. If the number of dispatches satisfies the relationship of N _b (T, n ₁ , n ₂ ,..., N _K ) ≦ Np using the above-mentioned maintenance staff N and dispatch limit p, the optimum maintenance created The plan can be executed. If the above equation is not satisfied, the created optimum maintenance plan cannot be executed.

  When creating a maintenance plan for a plurality of parts, the optimization unit 430 evaluates the total cost and the number of dispatches of maintenance personnel by such a procedure. The number of times the maintenance staff is dispatched in the entire maintenance plan for a plurality of parts is represented by the sum of the number of dispatches of the maintenance staff for each part. For this reason, for the entire maintenance plan of a plurality of parts, the total number of dispatches of maintenance personnel is evaluated. In order to execute an optimal maintenance plan, the following two methods are conceivable. The first is to increase the dispatchable limit p. This approach addresses the improvement of individual abilities, but is not expected to increase dramatically. The second is to increase the number of maintenance personnel. This method relies on management decisions. That is, the result of evaluating the number of dispatches of maintenance personnel according to the procedure of the present embodiment can be used for management decision making.

  Next, a maintenance plan creation process by the maintenance plan creation device 400 according to the fourth embodiment configured as described above will be described with reference to FIG. FIG. 24 is a flowchart showing the overall flow of the maintenance plan creation process in the fourth embodiment.

  First, the information reception unit 410 receives input of address information including an address ID and maintenance staff information (step S2401). The regeneration function calculation process, the expected cost function calculation process, and the expected cost optimization process from step S2402 to step S2404 are the same as those from step S1202 to step S1204 in the maintenance plan creation apparatus 200 according to the second embodiment. Since it is a process, its description is omitted.

Next, the third calculation unit 435 calculates the number of dispatches of maintenance personnel by substituting the calculated optimum reference period T ^* into T in the above equation (18) (step S2405). Then, the thirty-third calculation unit 435 determines whether or not the calculated number of dispatches is equal to or less than a threshold value Np (step S2406).

  If the number of dispatches is less than or equal to the threshold value Np (step S2406: YES), it means that an optimal maintenance plan can be executed, and therefore the creation unit 140 creates a maintenance plan that optimizes the expected cost (step S2407). . Further, the display unit 150 displays the created maintenance plan (step S2408) and ends the maintenance plan creation process.

  If the number of dispatches is not less than or equal to the threshold value Np (step S2406: NO), it means that the optimum maintenance plan cannot be executed, and therefore the display unit 150 outputs a message indicating that the maintenance plan cannot be executed (step S2409). Then, the maintenance plan creation process ends.

  Next, a specific example of the relationship between the number of dispatches of maintenance personnel and the possible limit of dispatch will be described. FIG. 25 is a graph showing an example of the relationship between the total cost, the number of times the maintenance staff is dispatched, and the lower limit of the number of dispatches. The horizontal axis of the figure represents the reference period. The solid line 2501 represents the total cost, the dotted line 2502 represents the number of times the maintenance staff has been dispatched, the dotted line 2503 represents the lower limit (Np) of the number of dispatches, and the dotted line 2504 represents the convergence value of the number of dispatches of the maintenance staff.

  In addition, this figure shows that maintenance can be performed at a reference cycle on the right side of an intersection 2511 between a dotted line 2502 that is the number of times the maintenance staff is dispatched and a dotted line 2503 that is the lower limit of the number of dispatches. As shown in the figure, the minimum value of the solid line 2501 that represents the total cost is in the region to the left of the intersection 2511. That is, in this example, since the lower limit Np of the number of dispatches is small, optimal block replacement cannot be executed.

(Modification 1)
In the past, maintenance plans were created by evaluating the expected costs and the number of dispatches of maintenance personnel when replacing parts that were actually used. In general, parts have different prices depending on their average life and performance even if they have the same function. Therefore, if the maintenance plan when the replacement part is introduced and the maintenance plan when the conventional part is used are created and the total cost and the number of times the maintenance staff is dispatched are compared, the effect of the replacement part introduction can be verified.

  This modification is configured to evaluate the expected cost and the number of dispatches of maintenance personnel when a substitute part that replaces a part that is actually used is introduced. In other words, in this modification, information on alternative parts such as the price of alternative parts, failure loss, and maintenance staff costs is input as part information, and the expected cost and the number of dispatches of maintenance staff can be evaluated using the same method as above. To do. Thereby, the economic effect at the time of introducing a substitute part can be estimated.

(Modification 2)
In this modification, the maintenance plan creation by periodic maintenance (block replacement) of the fourth (or second) embodiment and the maintenance plan creation by temporal maintenance (age replacement) of the third embodiment are performed. Run together. That is, in this modification, the total cost after convergence is set as the cost of the maintenance plan by the method of the third embodiment that applies age replacement. At the same time, the total cost of the maintenance plan by block replacement is calculated by the method of the fourth embodiment. In a maintenance plan based on block replacement, replacement is always executed simultaneously for parts having the same multiple cycle number.

  If the expected cost of the maintenance plan due to age replacement is larger than the expected cost due to block replacement, there may be waste in the plan. In this modification, it is possible to refer to a maintenance plan based on block replacement in order to correct plan waste. In other words, when the parts in the same cycle cluster created in the maintenance plan by block replacement are compared with the parts having a different multiple cycle number from the part, the use start date / time is different, or the replacement timing is shifted. In such a case, parts having different multiple cycle numbers can be intentionally replaced so that the same use start date and time is reached.

  For example, the expected cost due to age replacement and the expected cost due to block replacement are displayed, and the user who refers to the internal display matches the replacement date and time of the desired part with the multiple cycle number of the maintenance plan based on block replacement. It is configured to be changeable.

  FIG. 26 is a diagram illustrating an example of a maintenance plan displayed in the present modification. As shown in the figure, in this modification, a maintenance plan created by both block replacement and age replacement is displayed.

  As described above, the maintenance plan creation apparatus according to the fourth embodiment can estimate the number of dispatches of maintenance personnel and determine whether an optimum maintenance plan can be realized from the estimated number of dispatches.

  There are various variations of periodic maintenance, such as replacement of abandoned blocks and replacement of small repair blocks. If the expected cost and the number of maintenance personnel dispatches are corrected, each variation can be applied instead of the block replacement.

  Next, the hardware configuration of the maintenance plan creation device according to the first to fourth embodiments will be described with reference to FIG. FIG. 27 is an explanatory diagram illustrating a hardware configuration of the maintenance plan creation device according to the first to fourth embodiments.

  A maintenance plan creation device according to the first to fourth embodiments is connected to a control device such as a CPU (Central Processing Unit) 51, a storage device such as a ROM (Read Only Memory) 52 and a RAM 53, and a network. Connects each part to a communication I / F 54 that performs communication, an external storage device such as an HDD (Hard Disk Drive) and CD (Compact Disc) drive device, a display device such as a display device, and an input device such as a keyboard and a mouse. And a hardware configuration using an ordinary computer.

  A maintenance plan creation program executed by the maintenance plan creation device according to the first to fourth embodiments is a file in an installable format or an executable format, a CD-ROM (Compact Disk Read Only Memory), a flexible disk. (FD), CD-R (Compact Disk Recordable), DVD (Digital Versatile Disk) and the like are recorded and provided on a computer-readable recording medium.

  In addition, the maintenance plan creation program executed by the maintenance plan creation device according to the first to fourth embodiments is provided by being stored on a computer connected to a network such as the Internet and downloaded via the network. You may comprise as follows. The maintenance plan creation program executed by the maintenance plan creation device according to the first to fourth embodiments may be provided or distributed via a network such as the Internet.

  Moreover, you may comprise so that the maintenance plan preparation program of 1st-4th embodiment may be provided by previously incorporating in ROM etc.

  The maintenance plan creation program executed by the maintenance plan creation device according to the first to fourth embodiments includes a module configuration including the above-described units (information reception unit, function information output unit, optimization unit, creation unit). As the actual hardware, the CPU 51 (processor) reads the maintenance plan creation program from the storage medium and executes it, so that the respective units are loaded onto the main storage device, and the above-described units are loaded onto the main storage device. It is to be generated.

  It should be noted that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

51 CPU
52 ROM
53 RAM
54 Communication I / F
61 Bus 100, 200, 300, 400 Maintenance plan creation device 110, 410 Information receiving unit 120, 220, 320 Function information output unit 130, 330, 430 Optimization unit 131 Initialization unit 132, 332 First calculation unit 133 Storage unit 134, 334 Second calculation unit 435 Third calculation unit 140 Creation unit 150 Display unit 161, 261 Parts information storage unit 162 Expected cost storage unit 221 Playback function calculation unit 222, 322 Expected cost function calculation unit 321 Integration calculation unit 363 History storage Part 364 replacement schedule storage part

Claims (8)

A maintenance plan creation device that creates a maintenance plan that optimizes expected costs that represent costs required to replace each of a plurality of parts of equipment,
For each of a plurality of reference periods that serve as a reference for calculating a replacement period of the part, and for each part, a function defined for each part that inputs the replacement period and outputs the expected cost, The replacement cycle represented by a multiple of a reference cycle, each of which is input to the replacement cycle before and after the replacement cycle that outputs the minimum value of the expected cost, and is output from the function A first calculation unit that calculates a minimization period representing the replacement period in which the expected cost that is smaller among the expected costs is output;
Among the plurality of reference periods, the sum of the expected cost for each part output by inputting the minimization period into the function and the maintenance staff cost required for replacement in the reference period are minimized. A second calculation unit for calculating an optimum reference period representing the reference period;
For each of the parts, a creation unit that creates a maintenance plan representing replacement with the minimized cycle calculated with respect to the optimum reference cycle;
A maintenance plan creation device characterized by comprising: The function inputs the replacement period, and outputs the expected cost when replacing the part by periodic maintenance in which the part is replaced at a fixed period.
The maintenance plan creation device according to claim 1. A third calculator that calculates the number of times a maintenance person is dispatched when replacing the part in the minimization period;
The creation unit compares the number of dispatches with a predetermined threshold, and creates the maintenance plan when the number of dispatches is equal to or less than the threshold;
The maintenance plan creation apparatus according to claim 2. The function inputs the replacement period, calculates an expected value of the number of failures that occur until the input replacement period, and outputs the expected cost according to the expected value;
The maintenance plan creation apparatus according to claim 2. The function inputs the replacement period, and outputs the expected cost when the part is replaced by maintenance over time when the part is replaced when a predetermined time has passed since the date and time when the part failed.
The maintenance plan creation device according to claim 1. The function inputs the replacement period, calculates a reliability representing a probability that no failure will occur before the input replacement period, and outputs the expected cost according to the reliability,
The maintenance plan creation device according to claim 5. The first calculation unit further repeats the calculation of the minimization period with a new reference date and time obtained by adding the minimization period calculated with respect to the optimal reference period,
The second calculation unit calculates a plurality of the optimum reference periods for the plurality of the minimized periods that are repeatedly calculated, and the converged optimum reference period when the optimum reference period converges to a constant value. Output,
The maintenance plan creation device according to claim 5. A maintenance plan creation method executed by a maintenance plan creation device that creates a maintenance plan for each of a plurality of parts of equipment,
The first calculation unit is determined for each of a plurality of reference periods that serve as a reference for calculating a replacement period of the part, and for each part that inputs the replacement period and outputs the expected cost for each part. The replacement period represented by a multiple of the reference period, and the replacement period before and after the replacement period for outputting the minimum value of the expected cost, respectively, A first calculation step of calculating a minimization period representing the replacement period in which the smaller expected cost is output among the two expected costs to be output;
The second calculation unit, among a plurality of the reference period, the expected cost for each of the parts that are output by inputting the minimization period to the function, maintenance personnel cost required for replacement in the reference period, A second calculation step of calculating an optimum reference period representing the reference period that minimizes the sum of
A creation step for creating a maintenance plan representing that the creation unit replaces with the minimization period calculated for the optimum reference period for each part;
A maintenance plan creation method characterized by comprising:

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