JP2017151901A - Maintenance plan method of plant facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To formulate a plant maintenance plan for suppressing a plant maintenance cost required for monetary loss of a plant facility operation body due to the out-of-inventory of spare articles and the spare article procurement.SOLUTION: A purchase cost of spare articles determined according to the number of stocks of the spare articles is calculated for each number of stocks with respect to each of a plurality of types of spare articles held for each of a plurality of types of equipment components of a plant facility, and a stock management cost of the spare articles is calculated for the number of stocks with respect to each of the plurality of types of spare articles, and the monetary loss arising from the stop of the plant facility or deterioration of the capability due to out of stock of the spare articles is calculated for each number of stocks with respect to each of the plurality of types of spare articles, and a provisional solution of the number of stocks is determined on the basis of the purchase cost, the stock management cost, and the monetary loss.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a technique for maintaining plant equipment having a long operation period until cancellation, and more specifically, to a method for formulating a maintenance plan for the plant equipment.

  In the plant maintenance planning method, plant maintenance plan candidates are generated on the basis of the inventory quantity of the parts required for plant equipment maintenance and the parts that make up the plant equipment. Inadequate amounts can cause the following problems: That is, due to the out of stock of the parts and members, there is a risk that the plant equipment is stopped or the capacity is lowered until the parts and members are procured, and the actual operation rate of the plant equipment is lowered. In particular, if a part or member with a long delivery time breaks down, the influence on the operating rate of the plant equipment is great. In addition, in order to keep the plant maintenance cost within the budget, it is necessary to reduce the cost of procurement and management of the parts and members by reducing useless inventory. Therefore, when formulating a maintenance plan for plant equipment, it is effective to optimize the inventory so that spare parts for parts and members with long delivery times are held in an appropriate amount.

  The following Patent Document 1 and Patent Document 2 are used when stocking a spare part that can be exchanged for the equipment and parts when it becomes necessary to exchange the equipment and parts constituting the plant equipment with a new one. Disclosure of technology related to inventory management. In the invention described in Patent Document 1, for each of a plurality of types of parts constituting a plant or system, the stock out-of-stock date when each part is out of stock, the reliability, usage rate, current inventory quantity, failure rate, etc. of each part For each component type. In addition, among the multiple types of parts that make up the plant or system, the parts that are estimated to reach the inventory out-of-stock date earlier will be ranked higher in the parts list so that the parts are selected according to the out-of-stock date. Rank. Patent Document 2 discloses a stored item, etc. stored in order to procure a storage item, a spare part, and a mobile device (hereinafter referred to as a stored item) for recovering from an electric accident when an electric accident occurs. A management system is disclosed. The storage product management system described in Patent Document 2 uses a risk assessment value for each item in the event of an accident and the number of facilities required for accident recovery, and storage for accident recovery used for accident recovery. Calculate the number of goods held.

JP 2013-122761 A JP 2007-108885 A

  However, in the inventions described in Patent Document 1 and Patent Document 2, the spare parts are procured by reducing the useless inventory for each of the plurality of types of spare parts and holding an appropriate amount of inventory according to the situation. And a mechanism for reducing the cost of maintaining inventory as much as possible is not disclosed. Moreover, in invention of patent document 1 and patent document 2, after evaluating the financial damage assumed when the said spare part runs out of stock, based on the said assumed financial damage, the said spare part The system for judging the appropriate level of inventory is not disclosed.

  In view of the above-mentioned problems, some embodiments according to the present invention provide a plant maintenance plan that suppresses as much as possible the financial loss of the plant facility operating entity due to the out of stock of spare parts and the plant maintenance costs required for spare parts procurement. The purpose is to obtain a plant maintenance planning method that can formulate

(1) A plant facility maintenance planning method according to some embodiments of the present invention includes:
For each of a plurality of types of spare parts held for each of a plurality of types of equipment components of the plant facility, the purchase cost of the spare parts determined according to the number of the inventory of the spare parts is calculated for each number of the inventory. Purchase cost determination step,
For each of the plurality of types of spare parts, an inventory management cost determination step for calculating, for each inventory quantity, an inventory management cost of the spare parts determined according to the inventory quantity of the spare parts;
For each of the plurality of types of spare parts, a loss calculating step for calculating a monetary loss due to the plant equipment being shut down or being reduced in capacity due to out of stock of the spare parts for each inventory quantity;
For each of the plurality of types of spare parts, a provisional inventory quantity determination step for determining a provisional solution of the inventory quantity based on the purchase cost, the inventory management cost, and the monetary loss;
It is characterized by providing.

  In the method of (1) above, among the equipment components constituting the plant equipment, monetary items resulting from the suspension of the plant equipment or a reduction in capacity when the spare parts to be replaced with the failed equipment components are out of stock. Considering the loss, the provisional solution for the number of spare parts in stock is calculated. At the same time, in the method of (1) above, the provisional number of the spare parts is tentatively considered in consideration of the purchase cost and inventory management cost of the spare parts that should be kept in stock for replacement with the failed equipment component. The solution is calculated. As a result, according to the method of (1) above, by formulating an appropriate number of spare parts in stock, the plant equipment operating entity's financial loss due to out of stock of spare parts and plant maintenance required for spare parts procurement A plant maintenance planning method capable of suppressing costs as much as possible can be realized.

(2) In an exemplary embodiment, in the method of (1) above, for each of one or more parts of the plurality of types of equipment component parts, the capacity reduction of the plant facility when the parts fail An inventory necessity determination step for determining necessity of each of the parts based on a degree, a failure rate of the parts, and a delivery date of the spare parts for the parts;
In the provisional inventory number determination step, the provisional solution of the inventory number is determined to be zero for the spare part for the part that is determined to be unnecessary in the inventory necessity determination step.
It is characterized by that.

  In the method (2), for each of one or more parts among a plurality of types of equipment component parts, the degree of deterioration in the capacity of the plant facility when the part fails, the failure rate of the part, Therefore, it is determined whether or not each of the parts is in stock based on the delivery date of the spare parts. Therefore, according to the method (2), even if a failure occurs, for example, a spare part for a part that can have a small influence on the plant operation status, a part that can be procured in a short period of time, or a highly reliable part. It is possible to determine that no inventory is needed. As a result, in the method (2), it is possible to save the cost required for plant maintenance by the amount that the spare parts determined to be unnecessary are not held as inventory.

(3) In an exemplary embodiment, in the above method (1) or (2), when at least one of the following conditions (a) or (b) is satisfied, at least one of the plurality of types of spare parts: The method further comprises an inventory quantity correcting step for correcting the inventory quantity of the provisional solution.
(A) The sum of the operating efficiency improvement widths of the plant equipment by holding each of the plurality of types of spare parts by the number of stocks of the provisional solution is less than the target operating capacity improvement amount of the plant equipment.
(B) The total sum of the purchase cost and the inventory management cost for each of the plurality of types of spare parts exceeds the inventory-related budget.

  According to the above method (3), when at least one of the above conditions (a) or (b) is satisfied, at least one of a plurality of types of spare parts to be replaced with a failed device component is the above (1). ) To correct the number of stocks determined as a provisional solution. Specifically, in the method of (3) above, when the number of stocks determined as a provisional solution according to the method of (1) above for each of the plurality of types of spare parts is held, Is less than the target value, the inventory number of the provisional solution is corrected so that the operating rate improvement range is equal to or greater than the target value. Also, in the method (3) above, when the number of stocks determined as a tentative solution according to the method (1) above for each of the plurality of types of spare parts is held, the cost for inventory procurement and inventory management is the budget. If it exceeds, the number of stocks of the provisional solution is corrected so that the cost is within the budget.

  As a result, according to the method (3) above, the inventory determined as a provisional solution for each of the plurality of types of spare parts so that the sum of the improvement rates of the operation rate of the plant equipment can achieve the target value. The number can be corrected. In addition, according to the method (3), the number of stocks determined as a provisional solution can be corrected for each of the plurality of types of spare parts so that the costs for inventory procurement and inventory management are within the budget. .

  (4) In an exemplary embodiment, in the method of (3) above, in the inventory quantity correction step, at least the rate of change of the operating rate improvement range with respect to the increase / decrease amount of the inventory quantity from the provisional solution is maximum. The number of the spare parts in stock is increased.

  In the method of (4) above, when correcting the number of stocks determined as a provisional solution for each of a plurality of types of spare parts, it is possible to make the sum of the improvement rates of the plant equipment operating rate more than the target value. In addition, it is as follows. That is, in the method (4) above, when the number of stocks is increased or decreased from the provisional solution, the inventory of spare parts that maximizes the rate of change in the operating rate improvement of the plant equipment according to the amount of increase or decrease in the number of stocks. I try to increase the number. Therefore, in the above method (4), the condition that the sum of the improvement rates of the plant equipment utilization rate attains the target value when increasing or decreasing the inventory quantity for any one or more of the plurality of types of spare parts from the provisional solution. It is possible to modify the inventory quantity for the spare parts that are most effective to satisfy.

  (5) In an exemplary embodiment, in the method of (3) or (4) above, in the inventory quantity correction step, at least the purchase cost with respect to the increase / decrease amount of the inventory quantity from the provisional solution, the inventory The spare part in which the first change rate of the management cost or the total cost is maximized, the spare part in which the second change rate of the monetary loss with respect to the increase / decrease amount of the inventory from the provisional solution is the minimum, or The number of the spare parts in stock having a minimum ratio of the second change rate to the first change rate is reduced.

  In the method (5) above, a provisional solution is determined for each of the plurality of types of spare parts so that the cost required for inventory procurement and / or inventory management for the plurality of types of spare parts can be kept within the budget. When correcting the number of stocks made, we do the following. In other words, the number of spare parts in stock that maximizes the rate of change when the cost of inventory procurement and / or inventory management changes with respect to the amount of increase / decrease when the number of inventory determined as the provisional solution is increased or decreased. Try to reduce from. Thereby, in the method (5), it is possible to adjust the number of stocks for spare parts that can most effectively reduce the cost required for inventory procurement and / or inventory management.

  In the above method (5), when the number of stocks determined as a provisional solution for each of a plurality of types of spare parts is corrected so that the cost required for plant maintenance can be kept within the budget, Like that. That is, the number of spare parts in stock that minimizes the rate of change in monetary loss relative to the amount of increase or decrease in the number of stocks from the provisional solution is reduced from the provisional solution. Accordingly, in the method (5), when the number of stocks is reduced by a predetermined amount, the number of stocks can be adjusted for a spare part with the smallest possible increase in monetary loss caused by a plant stoppage or the like when the stock is out of stock. It becomes possible.

  In the above method (5), the rate of change in the cost required for inventory procurement and / or inventory management with respect to the amount of increase / decrease in inventory from the provisional solution is defined as the first rate of change, and the amount of increase / decrease in inventory from the provisional solution When the rate of change in monetary loss is the second rate of change, the following measures are taken. That is, the number of spare parts in stock having a minimum ratio of the second change rate to the first change rate is reduced from the provisional solution so that the cost required for plant maintenance can be kept within the budget. Accordingly, in the method (5), when the number of stocks is reduced by a predetermined amount, the amount of increase in monetary loss caused by a plant stoppage or the like when the stock is out of stock is as small as possible. It is possible to adjust the number of stocks for spare parts that can most effectively reduce the cost required for the maintenance.

(6) In an exemplary embodiment, in the method of (1) to (5) above, in the loss calculation step,
For each of the plurality of types of spare parts, calculate the stop time or the capacity reduction time of the plant equipment due to the out of stock of the spare parts for each stock quantity,
The calculated loss time of the plant equipment or the reduced capacity time is multiplied by the lost profit per unit time caused by the stop of the plant equipment or the reduced capacity, and the monetary loss is calculated for each inventory quantity. It is characterized by calculating.

  In the above method (6), the above-described monetary loss is evaluated by further considering the length of the period in which the plant equipment is in a state of shutdown or reduced capacity and the increase or decrease in lost profit per unit time within the period. . Therefore, according to the above method (6), the loss of money per unit time is further considered in addition to the above-mentioned stop time or capacity reduction time, and the monetary loss is evaluated with high accuracy for each inventory quantity. be able to. For this reason, the method described in (1) above is used to reduce monetary loss due to plant equipment outages or reduced capacity due to out of stock of spare parts, purchase costs and inventory management costs according to the number of spare parts in stock. Considering this, a provisional solution for the number of spare parts in stock can be calculated appropriately.

(7) In an exemplary embodiment, in the method of (1) to (6) above, in the provisional inventory quantity determination step,
Regarding the periodic replacement parts among the plurality of types of equipment component parts, the period from the inventory holding examination reference time to the next periodic replacement time is the same as or longer than the preparation period determined according to the delivery date of the periodic replacement parts And determining a provisional solution for the number of inventory based on the purchase cost, the inventory management cost and the monetary loss for the periodic replacement part,
When the period is shorter than the preparation period, the inventory number of the periodic replacement parts is determined to be greater than or equal to the number of the periodic replacement parts necessary for the periodic replacement work.

Among multiple types of equipment component parts, regarding the periodical replacement parts, there is a period from the time of considering how much the corresponding spare parts should be in stock (the time when the stockholding examination reference point is considered) to the time of the next periodic replacement I know in advance. If there is sufficient time before the next periodic replacement time compared to the preparation period determined according to the delivery date of the spare parts for the periodic replacement product at the time of inventory retention examination standard, It does not have to be held at the time of inventory retention consideration. On the other hand, if there is not enough time before the next periodic replacement time compared to the preparation period determined according to the delivery date of the spare parts for the periodic replacement product, It is necessary to keep a stock of regular replacement parts at the time.
In this regard, according to the method (7) above, when the period from the inventory holding reference point to the next periodic replacement point is shorter than the preparation period, it is necessary for the periodic replacement work regardless of the provisional solution of the inventory quantity. By setting the number of stocks in excess of the number of regular periodic replacement parts, regular replacement work can be carried out without delay. On the other hand, when the period from the inventory holding examination reference time to the next periodic replacement time is the same as the preparation period or longer than the preparation period, the provisional solution for the number of inventory is decided. Based on the monetary loss, the number of regular replacement parts in stock can be determined appropriately.

(8) In an exemplary embodiment, in the method of (1) to (7), the plant is determined based on the inventory quantity determined by the provisional inventory quantity determination step for each of the plurality of types of spare parts. A maintenance menu candidate generation step for generating a plurality of maintenance menu candidates for the facility;
A step of calculating a change in the operating rate of the plant equipment depending on whether or not each of the maintenance menu candidates is implemented; an operating rate change calculating step;
A profit change calculating step for calculating a change in profit obtained by operating the plant equipment based on whether or not each of the maintenance menu candidates is implemented based on the change in the operation rate;
A selection step of selecting at least one of the combinations satisfying at least one of the plurality of combinations of the maintenance menu candidates based on the change in the revenue;
Is further provided.

  In the method (8) above, a change in the operating rate of the plant equipment is obtained according to whether or not a plurality of maintenance menu candidates are implemented, and the maintenance menu is calculated based on the change in the profit calculated based on the change in the operating rate. Select a candidate combination. Therefore, in the above method (8), not only the maintenance cost and the damage cost caused by the plant stoppage are suppressed, but also the result obtained by evaluating the profit obtained from the operation of the plant based on the expected improvement in the plant operation rate. The maintenance menu combination can be reasonably determined in consideration. Thereby, in the method of said (8), the combination of the maintenance menu which can fully expect the improvement of the profit obtained from the improvement expectation of a plant operation rate can be determined rationally.

  In the method (8), at least one combination is selected from among a plurality of combinations of maintenance menu candidates from combinations that satisfy at least one constraint condition based on the change in the profit. As a result, in the method (8), when performing a plant maintenance plan, the two requirements that are in a trade-off relationship between the improvement in profits obtained from the plant operation and the satisfaction of the desired constraints to be satisfied by the plant are compatible. A combination of maintenance menus can be selected.

  Furthermore, according to the method of (8) above, since a plurality of maintenance menu candidates for the plant equipment is generated based on the inventory quantity of each spare part determined in the provisional inventory quantity determination step, A suitable combination of maintenance menu candidates that can actually be performed can be selected according to the number of stocks.

(9) In an exemplary embodiment, in the above methods (1) to (8), an inventory quantity condition setting step for setting an inventory quantity condition that is a combination of the inventory quantities of the plurality of types of spare parts. When,
A maintenance menu candidate generation step for generating a plurality of maintenance menu candidates for the plant equipment based on the inventory quantity condition;
A constraint condition determination step for determining whether or not a maintenance constraint condition is satisfied for each of one or more maintenance menu set candidates including a combination of at least one maintenance menu candidate among the plurality of maintenance menu candidates;
Is further provided.

  In the above method (9), maintenance menu candidates are generated based on the inventory quantity condition of spare parts. Therefore, a suitable combination of maintenance menu candidates that can actually be performed is selected according to the inventory quantity of each spare part. can do. Further, according to the method (9), it is possible to evaluate in advance whether or not the maintenance constraint condition is satisfied for each of one or more maintenance menu set candidates.

  (10) In an exemplary embodiment, in the method of (9) above, the maintenance constraint condition is a first condition indicating whether a maintenance cost necessary for executing the maintenance menu set candidate is within a maintenance budget. Or at least one of the 2nd conditions of whether the expected operation rate of the said plant equipment when the said maintenance menu set candidate is implemented is more than a target operation rate is characterized by the above-mentioned.

  Thereby, according to the method of (10) above, for each of one or more maintenance menu set candidates, a condition that the maintenance cost necessary for long-term maintenance of the plant is within a predetermined budget (first condition) or during the maintenance period It can be evaluated in advance whether or not the actual plant operating rate of the plant satisfies the condition (second condition) that it does not fall below the target operating rate.

  (11) In an exemplary embodiment, in the method of (9) or (10) above, when the maintenance constraint condition is not satisfied for all the maintenance menu set candidates, one or more in the previous inventory quantity condition The method further comprises a stock quantity condition correcting step for changing the stock quantity of the spare part.

  In the above method (11), if the maintenance constraint condition is not satisfied for all the maintenance menu set candidates generated according to the method (9) or (10), the inventory of one or more spare parts in the previous inventory number condition I try to change the number. At that time, if the stock quantity is appropriately changed, the possibility of finding a maintenance menu candidate that satisfies the maintenance constraint condition can be increased.

(12) In an exemplary embodiment, in the method of (11), the maintenance constraint condition is a first condition indicating whether a maintenance cost necessary for executing the maintenance menu set candidate is within a maintenance budget. Including
In the inventory quantity condition correction step,
If the first condition is not satisfied for all the maintenance menu set candidates, at least a third of the purchase cost, the inventory management cost, or the total cost with respect to the increase / decrease amount of the inventory quantity from the previous inventory quantity condition The spare part having the maximum rate of change, the spare part having the smallest fourth change rate of the monetary loss with respect to the increase / decrease amount of the stock quantity from the previous inventory quantity condition, or the third change ratio The number of the spare parts in stock having a minimum ratio of the fourth rate of change to is reduced.

  In the above method (12), since the maintenance constraint condition is not satisfied for all the maintenance menu set candidates, when changing the inventory quantity of one or more spare parts in the previous inventory quantity condition, the following measures are taken. Yes. That is, in the method (12), it is possible to reduce the number of stocks of spare parts that can most effectively reduce the cost required for inventory procurement and / or inventory management. In the method (12), when the number of stocks is reduced by a predetermined amount, it is possible to reduce the number of stocks for spare parts with the smallest possible increase in monetary loss due to plant stoppage when stock is out of stock. It becomes.

In the above method (12), the change rate of the cost required for inventory procurement and / or inventory management with respect to the increase / decrease amount of the inventory number is the third change rate, and the change rate of the monetary loss with respect to the increase / decrease amount of the inventory number is the first change rate. When the rate of change is four, the following measures are taken. That is, the number of spare parts that have the smallest ratio of the fourth change rate to the third change rate is reduced so that the cost required for plant maintenance can be kept within the budget. Accordingly, in the method of (12), when the number of stocks is reduced by a predetermined amount, the increase in monetary loss caused by a plant stoppage or the like when the stock is out of stock is as small as possible, and the stock procurement and / or stock management is performed. It is possible to reduce the number of stocks of spare parts that can most effectively reduce the cost required for the maintenance.
In this way, by correcting the inventory quantity condition, it is possible to increase the possibility of finding a maintenance menu set candidate that satisfies the maintenance constraint condition (first condition that the maintenance cost necessary for executing the maintenance menu set candidate is within the maintenance budget). .

(13) In an exemplary embodiment, in the method of (11) or (12), the maintenance constraint condition is that the expected operation rate of the plant facility when the maintenance menu set candidate is executed is a target operation rate. Including the second condition whether or not
In the inventory quantity condition correction step,
If the second condition is not satisfied for all the maintenance menu set candidates, the increase in the operating rate of the plant equipment due to the inventory of the spare parts with respect to the increase / decrease amount of the inventory quantity from the previous inventory quantity condition The number of the spare parts in stock having the highest rate of change is increased.

  In the method (13), the second condition (the expected operating rate of the plant facility when the maintenance menu set candidate is executed is obtained for all the maintenance menu set candidates generated according to the method (9) or (10). When the stock quantity of one or more spare parts in the previous stock quantity condition is changed due to the fact that it is equal to or higher than the target operation rate, the following measures are taken. That is, in the method (13), when the number of stocks is increased or decreased, the number of spare parts in stock that maximizes the rate of change in the operating rate improvement of the plant equipment is increased according to the amount of increase or decrease in the number of stocks. I have to. Therefore, in the above method (13), when the number of stocks is increased or decreased for any one or more of the plurality of types of spare parts, the condition that the sum of the improvement rates of the operating rate of the plant equipment achieves the target value is satisfied. It is possible to adjust the inventory quantity for the most effective spare parts.

  Thus, the maintenance menu set candidate that satisfies the maintenance constraint condition (second condition that the expected operating rate of the plant equipment when the maintenance menu set candidate is executed is equal to or higher than the target operating rate) may be found by correcting the inventory quantity condition. Can be increased.

(14) A computer system according to some embodiments includes a maintenance plan server that formulates a maintenance plan for plant equipment, and the maintenance plan server includes:
For each of a plurality of types of spare parts held for each of a plurality of types of equipment components of the plant facility, the purchase cost of the spare parts determined according to the number of the inventory of the spare parts is calculated for each number of the inventory. Purchase cost determination means,
For each of the plurality of types of spare parts, inventory management cost determining means for calculating the inventory management cost of the spare parts determined according to the inventory quantity of the spare parts for each inventory quantity;
For each of the plurality of types of spare parts, a loss calculating means for calculating a monetary loss due to the plant equipment being shut down or being reduced in capacity due to out-of-stock of the spare parts, for each number of stocks;
For each of the plurality of types of spare parts, provisional inventory quantity determining means for determining a provisional solution of the inventory quantity based on the purchase cost, the inventory management cost, and the monetary loss;
It is characterized by providing.

  In the configuration of (14) above, among the equipment components constituting the plant equipment, monetary due to the stoppage of the plant equipment or a reduction in capacity when the spare parts to be replaced with the failed equipment component parts are out of stock. Considering the loss, the provisional solution for the number of spare parts in stock is calculated. At the same time, in the configuration of (14) above, the provisional number of the spare parts is tentatively considered in consideration of the purchase cost and inventory management cost of the spare parts that should be kept in stock for replacement with the failed equipment component. The solution is calculated. As a result, according to the configuration of the above (14), by formulating an appropriate number of stocks of the spare parts, the financial loss of the plant facility operating entity due to the out of stock of the spare parts and the plant maintenance required for the procurement of the spare parts It is possible to realize a computer system for plant maintenance planning that can suppress costs as much as possible.

  From the above, according to some embodiments according to the present invention, a plant maintenance plan is established to suppress as much as possible the financial loss of the plant facility operating entity due to the out of stock of spare parts and the plant maintenance costs required for spare parts procurement. Possible plant maintenance planning methods can be obtained.

It is a figure which shows the structure of the plant equipment which concerns on one Embodiment of this invention. It is a flowchart explaining the detail of the stock initial condition determination process in the plant maintenance planning method which concerns on some embodiment of this invention. It is a flowchart for demonstrating the processing content of the provisional solution calculation stage in the stock quantity optimization process. It is a curve graph which shows a mode that the total amount of expense required for the procurement and management of money loss and inventory changes according to the change of the stock quantity of a spare part. It is a figure shown about each time on the time-axis used as a reference | standard when performing stock quantity optimization process. It is a numerical example for demonstrating the exemplary scenario of the process which corrects the number of stocks as a temporary solution calculated in the temporary solution calculation step. It is a numerical example for demonstrating the exemplary scenario of the process which corrects the number of stocks as a temporary solution calculated in the temporary solution calculation step. It is a numerical example for demonstrating the exemplary scenario of the process which corrects the number of stocks as a temporary solution calculated in the temporary solution calculation step. It is a figure which shows the one or more combination (maintenance menu set) of the maintenance menu candidate selected for a plant maintenance plan. It is a figure which shows the whole computer system for the plant maintenance plan which concerns on one Embodiment of this invention. It is a figure which shows the internal structure of the maintenance plan server which concerns on one Embodiment of this invention. It is a figure which shows the whole flow of the plant maintenance planning method which concerns on one Embodiment of this invention.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Absent.
For example, an expression indicating that things such as “identical”, “equal”, and “homogeneous” are in an equal state not only represents an exactly equal state, but also has a tolerance or a difference that can provide the same function. It also represents the existing state. On the other hand, the expressions “comprising”, “comprising”, “comprising”, “including”, or “having” one constituent element are not exclusive expressions for excluding the existence of the other constituent elements.
Hereinafter, before describing the maintenance plan method for a plant facility according to some embodiments, an example of the plant facility to which the maintenance plan method is applied will be described with reference to FIG. Next, processing contents of the maintenance planning method will be described with reference to FIGS.

  FIG. 1 shows an example of plant equipment to which a maintenance planning method according to some embodiments of the present invention is applied. The plant facility 1 is a simple specific example of a coal-fired power plant, and has a boiler 2. The boiler 2 includes a furnace wall 4 in which a furnace (combustion chamber) 3 is formed, a burner 5 installed in multiple stages below the furnace wall 4, and an outlet near the furnace 3. An air nozzle 6 for supplying to the furnace 3, a flue 7 connected to the outlet of the furnace 3, a superheater 8, a reheater 9 and an economizer 10 arranged in order from the upper part of the furnace 3 toward the flue 7; And a drum 11 provided at the top of the furnace 5. The furnace wall 4 is configured as a water-cooled wall in which a plurality of water pipes whose tube axis directions are directed in the vertical direction are arranged, and water that is superheated for driving the steam turbine passes through the water-cooled wall.

  The plant facility 1 further supplies a fuel supply means 12 for supplying fuel to the burner 5 and an air supply means 13 for supplying combustion air to the air nozzle 6 (air is supplied from the wind box 13b to the burner 5 via the air duct 13c). For example, and a heat exchanger 13d for exchanging heat between the supply air and the exhaust gas). The plant facility 1 further includes an exhaust gas line 14 for exhausting exhaust gas from the flue 7 to the outside (denitration device 14b interposed in the exhaust gas duct 14a for exhaust gas treatment, an electrostatic precipitator 14c, an induction fan 14d, desulfurization) Device 14e and chimney 14f).

  Further, after water supplied from a water supply pump (not shown) is preheated by exchanging heat with combustion gas in an economizer 10 arranged in a flue gas, it is further superheated while passing through the furnace wall 4, and from water and saturated steam. It becomes a gas-liquid two-phase flow. In this gas-liquid two-phase flow, the saturated water separated from the saturated steam by the drum 11 is sent back to the furnace wall 4 and reheated, and the saturated steam is further superheated by the superheater 8 to become superheated steam. Used to drive steam turbines. Moreover, the steam taken out in the middle of the expansion process by the steam turbine is reheated by the reheater 9 and supplied to the steam turbine again.

  Hereinafter, with reference to FIG. 2 thru | or FIG. 11, the maintenance plan method which selects a maintenance menu candidate from several maintenance menu candidates of the plant equipment 1 according to some embodiment of this invention is demonstrated. As described above with reference to FIG. 1, the plant facility 1 is composed of a plurality of devices, and in the following description, the plurality of devices, parts constituting these devices, and inspection and repair of these devices. Necessary members and the like are abstracted and described as device component parts D1, D2,..., D (j) and the like.

  In view of the fact that the plant maintenance plan candidates are generated based on the inventory of spare parts for each of the device components D1 to D (J), plant maintenance plans according to some embodiments of the present invention. As a characteristic configuration, the method has a mechanism for optimizing the inventory of the spare parts. Therefore, prior to describing the overall image of the plant maintenance planning method according to some embodiments of the present invention, first, a mechanism for performing the inventory optimization described above in the plant maintenance planning method will be described with reference to FIGS. This will be described with reference to FIG.

  FIG. 2 is a flowchart showing the flow of inventory initial condition determination processing that is performed as the first stage of inventory optimization in the plant maintenance planning method. The initial stock condition determination process shown in the flowchart of FIG. 2 is performed in three stages: an inventory necessity determination stage, an inventory quantity provisional solution calculation stage, and an inventory quantity correction stage. Specifically, in the flowchart of FIG. 2, the inventory necessity determination step corresponds to steps S21 to S25. In the flowchart of FIG. 2, the inventory quantity provisional solution calculation step corresponds to step S27. Further, in the flowchart of FIG. 2, the inventory quantity correction stage corresponds to step S28. Among the three stages described above, the inventory quantity provisional solution calculation stage plays an important role for inventory optimization. Therefore, prior to the description of the entire flowchart of FIG. 2, the inventory quantity provisional solution calculation step in the series of processing steps shown in FIG. 2 will be described in detail with reference to FIG.

FIG. 3 is a flowchart showing the flow of the inventory quantity provisional solution calculation stage executed as part of the inventory initial condition determination process shown in FIG. The flowchart of FIG. 3 starts execution from step S461. In step S461, spare parts E (j held for each of a plurality of types of equipment component parts D (j) (1 ≦ j ≦ J) of the plant facility 1 are used. ) (1 ≦ j ≦ J), the spare part E (j) (determined according to the stock quantity c (j) (1 ≦ j ≦ J) of the spare part E (j) (1 ≦ j ≦ J) ( The purchase cost O _j ^c (1 ≦ j ≦ J) of 1 ≦ j ≦ J) is calculated for each inventory quantity. That is, in step S461, the purchase cost O _j ^c of the spare part E (j) is the inventory quantity c (j) (1 ≦ j) for each of the plurality of types of device component parts D (j) (1 ≦ j ≦ J). ≦ J) is determined as a function that changes according to Here, E (j) (1 ≦ j ≦ J) is the device component D (j) (1 ≦ j ≦ J) when the device component D (j) (1 ≦ j ≦ J) fails. And c (j) (1 ≦ j ≦ J) represents the number of spare parts E (j) (1 ≦ j ≦ J) in stock. In addition, O _j ^c (1 ≦ j ≦ J) indicates that c (j) spare parts E () when the number of spare parts E (j) (1 ≦ j ≦ J) is equal to c (j) j) The purchase cost required to purchase (1 ≦ j ≦ J).

上記式（１）において、予備品Ｅ（ｊ）の部品価格とは、予備品Ｅ（ｊ）の１個当たりの単価である。この実施形態に係るプラント保守計画方法が、プラント保守計画策定用のコンピュータ・システムにより実行されている場合、予備品Ｅ（ｊ）の部品価格と諸費用は、当該コンピュータ・システムが備える部品情報データベース２２１ａから取得することが可能である。 In an exemplary embodiment, if the inventory of spare parts E (j) (1 ≦ j ≦ J) is equal to c (j), c (j) spare parts E (j) (1 ≦ j ≦ The purchase cost O _j ^c (1 ≦ j ≦ J) for purchasing J) from the seller may be calculated according to the following equation.

In the above formula (1), the part price of the spare part E (j) is the unit price per spare part E (j). When the plant maintenance planning method according to this embodiment is executed by a computer system for plant maintenance plan formulation, the part price and various expenses of the spare part E (j) are the part information database provided in the computer system. It can be obtained from 221a.

Subsequently, the execution of the flowchart of FIG. 3 proceeds to step S462, and in step S462, spare parts E (j) (1 ≦ j) for each of a plurality of types of spare parts E (j) (1 ≦ j ≦ J). An inventory management cost Q _j ^c (1 ≦ j ≦ J) of a spare part E (j) (1 ≦ j ≦ J) determined according to the inventory number c (j) of ≦ J) is calculated for each inventory number. That is, in step S461, the inventory management cost Q _j ^c (1 ≦ j) of the spare part E (j) (1 ≦ j ≦ J) for each of the plurality of types of device component parts D (j) (1 ≦ j ≦ J). j ≦ J) is obtained as a function that changes according to the stock quantity c (j) (1 ≦ j ≦ J). Q _j ^c (1 ≦ j ≦ J) is c (j) when the number of spare parts E (j) (1 ≦ j ≦ J) is equal to c (j) (1 ≦ j ≦ J). Inventory management cost required for inventory management of spare parts E (j) (1 ≦ j ≦ J).

上記式（１）において、複数種の予備品Ｅ（ｊ）（１≦ｊ≦Ｊ）の在庫保有コスト率とは、予備品Ｅ（ｊ）の単価に対する予備品Ｅ（ｊ）の１個あたりの在庫管理費用の比率である。この実施形態に係るプラント保守計画方法が、プラント保守計画策定用のコンピュータ・システムにより実行されている場合、予備品Ｅ（ｊ）の在庫管理コスト率は、当該コンピュータ・システムが備える在庫管理コスト率データベース２２３ａから取得することが可能である。 In an exemplary embodiment, c (j) spares when the number of stocks of multiple types of spare parts E (j) (1 ≦ j ≦ J) is equal to c (j) (1 ≦ j ≦ J). The inventory management cost Q _j ^c (1 ≦ j ≦ J) required for inventory management of the product E (j) (1 ≦ j ≦ J) may be calculated according to the following equation.

In the above formula (1), the inventory holding cost rate of a plurality of types of spare parts E (j) (1 ≦ j ≦ J) is the number of spare parts E (j) per unit price of spare parts E (j) Of inventory management costs. When the plant maintenance planning method according to this embodiment is executed by a computer system for plant maintenance plan formulation, the inventory management cost rate of the spare part E (j) is the inventory management cost rate of the computer system. It can be obtained from the database 223a.

Subsequently, the execution of the flowchart of FIG. 3 proceeds to step S463, and in step S463, spare parts E (j) (1 ≦ j) for each of a plurality of types of spare parts E (j) (1 ≦ j ≦ J). ≦ J) financial loss due to the stop or capacity reduction plant equipment 1 by shortage of ^{_{P j c (1 ≦ j ≦}} J) is calculated for each inventory. In other words, in step S461, for each of a plurality of types of device component parts D (j) (1 ≦ j ≦ J), money generated as a result of the out of stock of spare parts E (j) (1 ≦ j ≦ J). The dynamic loss P _j ^c is obtained as a function that changes according to the inventory quantity c (j).

In an exemplary embodiment, c (j) spares when the number of stocks of multiple types of spare parts E (j) (1 ≦ j ≦ J) is equal to c (j) (1 ≦ j ≦ J). The monetary loss P _j ^c (1 ≦ j ≦ J) caused by the out of stock of the product E (j) (1 ≦ j ≦ J) may be calculated as follows. First, for each of the plurality of types of spare parts E (j) (1 ≦ j ≦ J), the stop time or the capacity reduction time of the plant equipment 1 due to the out of stock of the spare parts E (j) (1 ≦ j ≦ J) Is calculated for each inventory number c (j) (1 ≦ j ≦ J). Subsequently, the calculated loss time of the plant equipment 1 or the capacity reduction time is multiplied by the lost profit per unit time caused by the stop of the plant equipment 1 or the capacity reduction, and the monetary loss P _j ^c ( 1 ≦ j ≦ J) is calculated for each stock quantity.

ここで、Ｔ_ＨＴ ^（ｊ）は、予備品Ｅ（ｊ）（１≦ｊ≦Ｊ）が在庫切れを起こしたことにより生じるプラント設備１の停止時間の長さを表し、Ｔ_ＬＴ ^（ｊ）は、予備品Ｅ（ｊ）（１≦ｊ≦Ｊ）が在庫切れを起こした時点から新品の予備品Ｅ（ｊ）（１≦ｊ≦Ｊ）が納品されるまでの納期の長さを表す。上記式（３−１）において、売電単価および発電容量は、プラント設備１全体の単位時間当たりの供給電力量に応じた売電価格およびプラント設備１全体の単位時間当たりの発電出力である。 More specifically, first, when each of the plurality of types of spare parts E (j) (1 ≦ j ≦ J) is out of stock, The loss P _j ^c (1 ≦ j ≦ J) may be calculated according to the following equation.

Here, T _HT ^(j) represents the length of the downtime of the plant equipment 1 caused by the out of stock of the spare parts E (j) (1 ≦ j ≦ J), and T _LT ^(j) is , Represents the length of the delivery date from the time when the spare part E (j) (1 ≦ j ≦ J) is out of stock until the new spare part E (j) (1 ≦ j ≦ J) is delivered. In the above formula (3-1), the power sale unit price and the power generation capacity are the power sale price according to the amount of power supplied per unit time of the whole plant facility 1 and the power generation output per unit time of the whole plant facility 1.

ここで、λ_ｊは、予備品Ｅ（ｊ）（１≦ｊ≦Ｊ）の故障率を表し、Ｊは、機器構成部品の総数を表す。また、図３のフローチャートに従って予備品Ｅ（ｊ）（１≦ｊ≦Ｊ）の在庫数を検討する対象となる時点を在庫数検討対象時点とすると、ｘは、在庫数検討対象時点から時間ｔが経過するまでに故障する予備品Ｅ（ｊ）の個数である。その上で、上記式（４−１）では、ｘの確率分布はポアソン分布に従うと仮定している。従って、上記式（４−１）において、ｍ_ｊは、故障率λ_ｊを有する予備品Ｅ（ｊ）（１≦ｊ≦Ｊ）の故障関数をポアソン分布曲線で表した際のポアソン分布曲線の形状を規定するポアソン分布パラメータである。また、上記式（４−１）において、Ｐ_ｒ（ｘ｜ｍ_ｊ）は、ｘ個の予備品Ｅ（ｊ）（１≦ｊ≦Ｊ）の少なくとも一つ以上が故障を起こしていないことにより、ｘ個の予備品Ｅ（ｊ）（１≦ｊ≦Ｊ）によって冗長構成されたシステム全体が稼働し続ける確率を表す信頼度関数である。 Α _j is the out-of-stock rate corresponding to the probability that the spare part E (j) (1 ≦ j ≦ J) will be out of stock at an arbitrary time, and is expressed by the following equation.

Here, λ _j represents the failure rate of the spare part E (j) (1 ≦ j ≦ J), and J represents the total number of device components. Further, if the time point at which the inventory quantity of the spare parts E (j) (1 ≦ j ≦ J) is examined according to the flowchart of FIG. Is the number of spare parts E (j) that fail before the time elapses. In addition, in the above equation (4-1), it is assumed that the probability distribution of x follows a Poisson distribution. Therefore, in the above equation (4-1), m _j is the Poisson distribution curve when the failure function of the spare part E (j) (1 ≦ j ≦ J) having the failure rate λ _j is represented by the Poisson distribution curve. It is a Poisson distribution parameter that defines the shape. Further, in the above formula (4-1), P _r (x | m _j ) is obtained by the fact that at least one of the x spare parts E (j) (1 ≦ j ≦ J) has not failed. , A reliability function representing the probability that the entire system configured redundantly with x spare parts E (j) (1 ≦ j ≦ J) will continue to operate.

上記式（５−１）において、（１−Ｌｄ^（ｊ））は、予備品Ｅ（ｊ）（１≦ｊ≦Ｊ）が在庫切れを起こした際に、プラント設備１の能力が低下する度合いを表し、（１−Ｌｄ^（ｊ））≦１となる重み係数である。例えば、予備品Ｅ（ｊ）（１≦ｊ≦Ｊ）が在庫切れを起こした際に、プラント設備１の発電出力が在庫切れ以前における出力のｗ％に低下したとすれば、Ｌｄ^（ｊ）＝ｗ×０．０１となり、Ｌｄ^（ｊ）は、機器構成部品Ｄ（ｊ）の負荷率と呼ばれる。 On the other hand, when the spare part E (j) (1 ≦ j ≦ J) is out of stock, the capacity of the plant equipment 1 is reduced, but the operation of the plant equipment can be continued with the reduced capacity. The monetary loss P _j ^c (1 ≦ j ≦ J) may be calculated according to the following equation.

In the above formula (5-1), (1-Ld ^(j) ) is the degree to which the capacity of the plant equipment 1 decreases when the spare part E (j) (1 ≦ j ≦ J) is out of stock. And a weighting coefficient satisfying (1−Ld ^(j) ) ≦ 1. For example, if the spare part E (j) (1 ≦ j ≦ J) is out of stock, and the power generation output of the plant facility 1 is reduced to w% of the output before the stock out, Ld ^(j) = W × 0.01, and Ld ^(j) is called the load factor of the device component D (j).

When the plant maintenance planning method according to this embodiment is executed by a computer system for formulating a plant maintenance plan, the power selling unit price and the power generation capacity are the power selling unit price / power generation capacity database provided in the computer system. 222a can be obtained. Further, the failure rate λ _{j of} the spare part E (j) (1 ≦ j ≦ J), the delivery time T _LT ^{(j) of} the spare part E (j) (1 ≦ j ≦ J), and the equipment configuration constituting the plant facility 1 The number J of components D (j) (1 ≦ j ≦ J) can be acquired from the component information database 221a included in the computer system.

Subsequently, the execution of the flowchart of FIG. 3 proceeds to step S464, and in step S464, the purchase cost O _j ^c (1 ≦ j ≦) for each of the plurality of types of spare parts E (j) (1 ≦ j ≦ J). J), a provisional solution for the inventory quantity c (j) is determined based on the inventory management cost Q _j ^c (1 ≦ j ≦ J) and the monetary loss P _j ^c (1 ≦ j ≦ J). In an exemplary embodiment, the provisional solution of the inventory quantity c (j) for each of the plurality of types of spare parts E (j) (1 ≦ j ≦ J) may be determined as follows. First, for each of the plurality of types of spare parts E (j) (1 ≦ j ≦ J), when the inventory quantity c (j) is increased or decreased, the purchase cost O _j ^c , inventory management cost Q _j ^c and monetary Find out how the total sum of losses P _j ^c changes as a function of inventory quantity c (j). Subsequently, for each of the plurality of types of spare parts E (j) (1 ≦ j ≦ J), when the stock quantity c (j) is increased or decreased, the stock quantity c _opt ( j) Find a provisional solution (1 ≦ j ≦ J).

Purchasing cost O _j ^c (1 ≦ j ≦ J), inventory management cost Q _j ^c (1 ≦ j ≦ J) and monetary loss when inventory quantity c (j) (1 ≦ j ≦ J) is increased or decreased FIG. 4 shows an example of a variation curve representing how the total sum of P _j ^c (1 ≦ j ≦ J) changes. Referring to the curve graph of FIG. 4, when the number c (ja) of spare parts E (ja) held as inventory is 17, the purchase cost O _ja ^c , inventory management cost Q _ja ^c and monetary loss P _ja It can be seen that the total sum of ^c is the smallest. When the number c (ja) of spare parts E (ja) held as stock is less than 17, the spare parts E (ja) run out of stock as the number of stocks c (ja) decreases. possibility is increased, correspondingly, the financial loss P _niv ^c suddenly increases rapidly increases the total amount from the minimum value. On the other hand, if the number c (ja) of spare parts E (ja) held as inventory is 18 or more, the excess inventory amount of the spare parts E (ja) increases as the number of inventory c (ja) increases. because depending on purchase costs O _ja ^c and inventory management costs Q _ja ^c is increased slowly, the total amount also increases slowly. Therefore, in this case, the provisional solution of the inventory quantity c _opt (ja) to be held for the spare part E (ja) can be determined to be 17.

As described above, in the embodiment shown in FIG. 3, a spare part to be replaced with a failed equipment component D (jd) among the plurality of types of equipment components D (j) (1 ≦ j ≦ J) of the plant facility 1. Considering the monetary loss P _jd ^c due to the shutdown of plant equipment 1 or the capacity reduction when E (jd) is out of stock, the provisional solution of the number c (jd) of spare parts E (jd) Is calculated. At the same time, in the embodiment shown in FIG. 3, the purchase cost O _jd ^c and the inventory management cost Q _jd ^{c of the} spare part E (j) to be held as stock for replacement with the failed device component D (jd). Is taken into consideration, the provisional solution of the inventory quantity c (jd) of the spare part E (jd) is calculated. As a result, according to the embodiment shown in FIG. 3, by formulating an appropriate inventory quantity of the spare part E (jd), the monetary loss of the operating entity of the plant facility 1 due to the out of stock of the spare part E (jd) In addition, it is possible to realize a plant maintenance planning method that can suppress plant maintenance costs required for spare parts procurement as much as possible.

In the embodiment shown in FIG. 3, the following technical advantages can be obtained by evaluating the monetary loss P _j ^{c according} to the above formula (4-1) or (5-1). That is, in such an embodiment, the monetary loss P _j ^c is evaluated by further taking into account the length of the period in which the plant facility 1 is in a state of shutdown or reduced capacity and the increase or decrease in lost profit per unit time within the period. doing. Therefore, according to this embodiment, in addition to the above-described stop time or capacity reduction time, the loss loss per unit time is further considered, and the monetary loss P _j ^c is evaluated with high accuracy for each inventory quantity. be able to. For this reason, in this embodiment, according to the procedure shown in the flowchart of FIG. 3, the monetary loss P _j ^c due to the plant facility 1 being stopped due to the out-of-stock of the spare part E (j) or the capacity reduction, and the spare part E In consideration of the purchase cost O _j ^c and the inventory management cost Q _j ^c according to the inventory quantity c (j) of (j), the inventory quantity c (of each spare part E (j) (1 ≦ j ≦ J) The provisional solution of j) can be calculated appropriately.

  Next, the flow of the entire inventory initial condition determination process including the inventory quantity provisional solution calculation stage shown in FIG. 3 will be described according to the flowchart of FIG.

The execution of the flowchart of FIG. 2 starts from step S21, and an unselected device component D (js) is selected from the device components D (j) (1 ≦ j ≦ J). Subsequently, the execution of the flowchart of FIG. 2 proceeds to step S22. In step S22, it is determined whether or not the device component D (js) is a periodic replacement product. If it is not a regular replacement product, the process proceeds to step S24. In step S23, for the equipment component D (js), the next periodic replacement time (T _{2 in} FIG. 5) from the stock holding examination reference time (T _{1 in} FIG. 5), which is the time when the inventory quantity is optimized. It is determined whether or not the period until (ΔT in FIG. 5) is longer than the preparation period (lead time) determined according to the delivery date of the regular replacement part. If the period ΔT (FIG. 5) until the next periodic replacement is shorter than the preparation period (lead time), the process proceeds to step S30. Otherwise, the process proceeds to step S24. In step S30, the number of periodic replacement parts in stock is determined to be equal to or greater than the number of periodic replacement parts necessary for the periodic replacement work.

Regarding the periodic replacement part D (js) among a plurality of types of equipment component parts, the time point at which the number of stocks of the corresponding spare parts should be held (the stock holding examination reference time point (T _{1 in} FIG. 5)) ) To the next periodic replacement time (T _{2 in} FIG. 5) is known in advance. If there is sufficient time before the next periodic replacement time compared to the preparation period determined according to the delivery date of the spare parts for the periodic replacement product at the time of inventory retention examination standard, It does not have to be held at the time of inventory retention consideration. On the other hand, at the time of stockholding examination reference time, there is sufficient time margin until the next periodic replacement time compared to the preparation period determined according to the delivery date of the spare part E (js) for the periodic replacement product D (js) If there is no inventory, it is necessary to keep the inventory of the regular replacement part D (js) at the inventory retention examination reference point (T _{1 in} FIG. 5).

In this regard, according to steps S21 to S23, the period ΔT (FIG. 5) from the inventory retention examination reference time (T _{1 in} FIG. 5) to the next periodic replacement time (T _{2 in} FIG. 5) is shorter than the preparation period. In this case, the regular replacement work can be carried out without delay by setting the number of stocks in excess of the quantity of the periodic replacement parts necessary for the periodic replacement work, regardless of the provisional solution of the stock quantity. On the other hand, if the period ΔT (FIG. 5) from the inventory holding examination reference time (T _{1 in} FIG. 5) to the next periodic replacement time (T _{2 in} FIG. 5) is the same as or longer than the preparation period, Since the provisional solution of the number is determined, the inventory number of the regular replacement parts can be appropriately determined based on the purchase cost O _js ^c , the inventory management cost Q _js ^c and the monetary loss P _js ^c . That is, in steps S21, S22, and S23 of the flowchart of FIG. 2, regarding the periodic replacement part D (js) among the equipment component parts D (j) (1 ≦ j ≦ J), the next periodic replacement from the inventory retention examination reference time point is performed. When the period ΔT (FIG. 5) until the time is shorter than the preparation period determined according to the delivery date of the regular replacement part D (js), the number of stocks c of the spare part E (js) corresponding to the regular replacement part D (js) (J) If ^s is determined to be equal to or greater than the number of periodic replacement parts necessary for the periodic replacement work, and the period ΔT (FIG. 5) is the same as or shorter than the preparation period, the periodic replacement part D The inventory quantity c (js) of the spare part E (js) corresponding to (js) is calculated according to the processing flow of steps S27 to S28.

  In step S24 of the flowchart of FIG. 2, the recommended inventory level is calculated for the selected device component D (js). The recommended inventory level for the device component D (js) is an evaluation index obtained by evaluating the necessary degree of inventory of the device component D (js). Note that the recommended stock level is a real number that is greater than or equal to zero. For the device component D (js), if the recommended stock level is zero, it is suggested that the stock is not required, and the recommended stock level is Greater than zero suggests a higher need for inventory. In an exemplary embodiment, the stock recommendation level for the equipment component D (js) is determined based on the degree of reduction in the capacity of the plant facility 1 when the equipment component D (js) fails, and the equipment component D (js). ) And the delivery date of the spare part E (js) for the equipment component D (js) may be obtained.

ここで、λ_ｊは、予備品Ｅ（ｊ）（１≦ｊ≦Ｊ）の故障率を表し、Ｔ_ＬＴ ^（ｊ）は、予備品Ｅ（ｊ）（１≦ｊ≦Ｊ）が在庫切れを起こした時点から新品の予備品Ｅ（ｊ）（１≦ｊ≦Ｊ）が納品されるまでの納期の長さを表す。また、（１−Ｌｄ^（ｊ））は、予備品Ｅ（ｊ）（１≦ｊ≦Ｊ）が在庫切れを起こした際に、プラント設備１の能力が低下する度合いを表し、（１−Ｌｄ^（ｊ））＜１となる重み係数である。例えば、予備品Ｅ（ｊ）（１≦ｊ≦Ｊ）が在庫切れを起こした際に、プラント設備１の発電出力が在庫切れ以前における出力のｗ％に低下したとすれば、Ｌｄ^（ｊ）＝ｗ×０．０１となり、Ｌｄ^（ｊ）は、機器構成部品Ｄ（ｊ）の負荷率と呼ばれる。 In an exemplary embodiment, the stock recommendation SR _j for the device component D (j) may be calculated according to the following equation:

Here, λ _j represents the failure rate of the spare part E (j) (1 ≦ j ≦ J), and T _LT ^(j) represents that the spare part E (j) (1 ≦ j ≦ J) is out of stock. It represents the length of the delivery date from the time of occurrence until the delivery of a new spare part E (j) (1 ≦ j ≦ J). Further, (1-Ld ^(j) ) represents the degree to which the capacity of the plant equipment 1 is reduced when the spare part E (j) (1 ≦ j ≦ J) is out of stock, and (1-Ld ^{(J) A} weighting coefficient such that) <1. For example, if the spare part E (j) (1 ≦ j ≦ J) is out of stock, and the power generation output of the plant facility 1 is reduced to w% of the output before the stock out, Ld ^(j) = W × 0.01, and Ld ^(j) is called the load factor of the device component D (j).

  Subsequently, the execution of the flowchart of FIG. 2 proceeds to step S25, and in step S25, it is determined whether or not the recommended stock degree calculated for the selected device component D (js) is greater than zero. If the recommended stock level is greater than zero, the process proceeds to step S26. If the recommended stock level is equal to zero, the process proceeds to step S29, and the spare part E (js) for the selected device component D (js). ) Is determined to be zero (determined that inventory is not necessary), and then the process returns to step S21.

As described above, by executing step S24, with respect to the currently selected equipment component D (js), the degree of reduction in the capacity of the plant facility 1 when the equipment component D (js) fails, and the equipment component D ( The necessity of inventory of the device component D (js) is determined based on the failure rate of js) and the delivery date of the spare part E (js) for the device component D (js). In addition, by executing step S25, the inventory quantity c (j) ^s is determined to be zero for the spare part E (js) for the equipment component D (js) that is determined not to require inventory.

  Therefore, in this embodiment, for each of one or more parts among the plurality of types of equipment component parts D (j) (1 ≦ j ≦ J), the degree of reduction in the capacity of the plant facility 1 when the parts fail Based on the failure rate of the part and the delivery date of the spare part E (j) (1 ≦ j ≦ J) for the part, the necessity of stock of each part is determined. Therefore, according to this embodiment, even if a failure occurs, for example, a part that can reduce the influence on the plant operation status, a part that can be procured in a short period of time, or a highly reliable part D (jx) It is possible to determine that the stock of the product E (jx) is unnecessary. As a result, in this embodiment, the cost required for plant maintenance can be saved by not storing the spare part E (jx) determined to be unnecessary.

Subsequently, the execution of the flowchart of FIG. 2 proceeds to step S26. In step S26, it is determined whether all the device components D (j) (1 ≦ j ≦ J) have been selected, and all the devices are determined. If the component D (j) (1 ≦ j ≦ J) has been selected, the process proceeds to step S27, and if not, the process returns to step S21. When the execution of the flowchart of FIG. 2 proceeds to step S27, it is determined whether or not inventory is necessary for all the device component parts D (j) (1 ≦ j ≦ J), and the device component parts D that are not required to be in stock. For (j) (j = j ₁ ,..., J _k ), the provisional solution for the inventory quantity c (j) is set to zero. Subsequently, in step S27, according to the flowchart shown in FIG. 3, the provision of the inventory quantity c (j) for all device component parts D (j) (j ≠ j ₁ ,..., J _k ) determined to be in stock. Calculate the solution.

In step S28, when at least one of the following conditions (a) or (b) is satisfied, calculation is made according to the flowchart of FIG. 3 for at least one of the plurality of types of spare parts E (j) (1 ≦ j ≦ J). The inventory quantity correction process for correcting the inventory quantity c (j) (1 ≦ j ≦ J) of the provisional solution is performed. (A) Improvement of the operation rate of the plant equipment 1 by holding each of a plurality of types of spare parts E (j) (1 ≦ j ≦ J) by the stock quantity c (j) (1 ≦ j ≦ J) of the provisional solution. The sum of the widths is less than the target improvement in the operating rate of the plant equipment 1. (B) The sum of the total costs of the purchase cost O _j ^c and the inventory management cost Q _j ^c for each of the plurality of types of spare parts E (j) (1 ≦ j ≦ J) exceeds the inventory-related budget.

  In an exemplary embodiment, the inventory quantity correction for correcting the provisional solution inventory quantity c (j) (1 ≦ j ≦ J) when at least one of the following conditions (a) or (b) is satisfied: Processing is performed as follows. That is, at least the spare part E in which the rate of change in the operating rate improvement range with respect to the increase / decrease amount Δc (j) (1 ≦ j ≦ J) of the stock quantity c (j) (1 ≦ j ≦ J) from the provisional solution is the maximum. (J) The stock quantity c (j) (1 ≦ j ≦ J) of the provisional solution is corrected by increasing the stock quantity c (j) ”of“ j ”.

  In this embodiment, a provisional solution is provided for each of a plurality of types of spare parts E (j) (1 ≦ j ≦ J) so that the sum of the operating rate improvement widths of the plant equipment 1 can be equal to or greater than the target value. When the stock quantity c (j) (1 ≦ j ≦ J) determined as is corrected, the following is performed. That is, in this embodiment, when the inventory quantity c (j) (1 ≦ j ≦ J) is increased or decreased from the provisional solution, the increase / decrease amount Δc (of the inventory quantity c (j) (1 ≦ j ≦ J) is increased. j) In accordance with (1 ≦ j ≦ J), the number of stocks of spare parts E (jm) that maximize the rate of change in the operating rate improvement width of the plant equipment 1 is increased. Therefore, in this embodiment, when the stock quantity c (j) (1 ≦ j ≦ J) is increased or decreased from the provisional solution for any one or more of the plurality of types of spare parts E (j) (1 ≦ j ≦ J). In addition, the inventory quantity c (jm) can be corrected for the most effective spare part E (jm) in order to satisfy the condition that the sum of the operating rate improvement widths of the plant equipment 1 achieves the target value.

In another exemplary embodiment, when at least one of the following conditions (a) and (b) is satisfied, the provisional solution inventory number c (j) (1 ≦ j ≦ J) is corrected: The stock quantity correction process is executed as follows. That is, at least the purchase cost O _j ^c and the inventory management cost Q _j ^{c for} the increase / decrease amount Δc (j) (1 ≦ j ≦ J) of the stock quantity c (j) (1 ≦ j ≦ J) from the provisional solution or these Stock quantity c (jq) of spare part E (jq) that maximizes the first rate of change in total cost, and increase / decrease amount Δc (j) of stock quantity c (j) (1 ≦ j ≦ J) from the provisional solution The stock quantity c (jp) of the spare part E (jp) in which the second change rate of the monetary loss P _j ^c with respect to (1 ≦ j ≦ J), or the second change rate with respect to the first change rate The inventory quantity c (jr) of the spare part E (jr) having the smallest ratio is reduced.

In this embodiment, a plurality of types of spare parts E (j) (1 ≦ j ≦ J) are used so that the cost required for inventory procurement and / or inventory management can be kept within the budget. When correcting the stock quantity c (j) (1 ≦ j ≦ J) determined as a provisional solution for each of the products E (j) (1 ≦ j ≦ J), the following is performed. That is, it is possible to adjust the inventory quantity c (js) for the spare part E (js) that can most effectively reduce the cost required for inventory procurement and / or inventory management. Further, in this embodiment, when the number of stocks determined as a provisional solution for each of a plurality of types of spare parts is corrected so that the cost required for plant maintenance can be kept within the budget, the following is performed. ing. That is, when the stock quantity c (j) (1 ≦ j ≦ J) is reduced by a predetermined amount, the increase amount of the monetary loss P _j ^c (1 ≦ j ≦ J) caused by the plant stoppage or the like when the stock is out of stock. The inventory quantity c (jt) can be adjusted for the spare part E (jt) as small as possible. Further, in this embodiment, when the stock quantity c (j) (1 ≦ j ≦ J) is reduced by a predetermined amount, the monetary loss P _j ^c (1 ≦ j ≦ J) that occurs due to a plant stoppage or the like when the stock is out of stock. ) Is as small as possible, and the number of stocks c (ju) can be adjusted for spare parts E (ju) that can most effectively reduce the cost required for inventory procurement and / or inventory management. .

  From the above, when at least one of the above conditions (a) or (b) is satisfied by executing the inventory quantity correction process in step S28, a plurality of types of parts to be replaced with a failed device component D (jd) For at least one spare part E (jd), a process of correcting the inventory quantity c (jd) determined as a provisional solution according to the flowchart of FIG. 3 is executed. Specifically, for each of the plurality of types of spare parts E (j) (1 ≦ j ≦ J), the inventory quantity c (j) (1 ≦ j ≦ J) determined as a provisional solution according to the flowchart of FIG. 3 was held. In this case, if the sum of the operating rate improvement widths of the plant equipment 1 is less than the target value, the inventory number c (j) (1 ≦ j ≦) of the provisional solution so that the operating rate improvement range is equal to or larger than the target value. J) is corrected. In addition, when the inventory number c (j) (1 ≦ j ≦ J) determined as a provisional solution according to the flowchart of FIG. 3 is held for each of the plurality of types of spare parts E (j) (1 ≦ j ≦ J), When the cost for inventory procurement and inventory management exceeds the budget, the inventory number c (j) (1 ≦ j ≦ J) of the provisional solution is corrected so that the cost is within the budget. Yes.

  As a result, by executing the inventory quantity correction process in step S28, the plurality of types of spare parts E (j) () so that the sum of the operating rate improvement widths of the plant equipment 1 can achieve the target value. The stock quantity c (j) determined as a provisional solution for each of 1 ≦ j ≦ J) can be corrected. Further, according to this embodiment, each of the plurality of types of spare parts E (j) (1 ≦ j ≦ J) is determined as a provisional solution so that the cost for inventory procurement and inventory management falls within the budget. The inventory quantity c (j) (1 ≦ j ≦ J) can be corrected.

Next, an exemplary scenario when the inventory optimization process shown by the flowchart of FIG. 2 is executed using the numerical examples shown in FIGS. 6A to 6C will be described. The table in FIG. 6A shows that the spare parts E (1) to E (6) are spare when the stock quantity c (1) to c (6) is increased or decreased from c = 0 to c = 10. Each of the products E (1) to E (6) represents the length of the plant downtime that is expected to be generated by causing the product to run out of stock. The table in FIG. 6B shows the purchase when the number of stocks c (1) to c (6) is increased or decreased from c = 0 to c = 10 for six types of spare parts E (1) to E (6). It shows how the sum of the cost O _j ^c and the inventory management cost Q _j ^c changes. The table in FIG. 6C shows money when the stock quantity c (1) to c (6) is increased or decreased from c = 0 to c = 10 for six types of spare parts E (1) to E (6). It shows how the amount of _static loss P _j ^c changes.

  When the processing of the entire flowchart of FIG. 3 corresponding to step S27 of FIG. 2 is executed using the numerical examples shown in FIGS. 6A to 6C as execution conditions, each of a plurality of types of spare parts E (1) to E (6) is executed. As provisional solutions for the preferred inventory numbers c (1) to c (6), c (1) = 8, c (2) = 7, c (3) = 4, c (4) = 3, c (5) = 4 and c (6) = 5. The provisional solution obtained in this way is represented by surrounding the position of the corresponding row for each of the spare parts E (1) to E (6) in the tables of FIGS. 6A to 6C with a square circle. One of the spare parts E (1) to E (6) is obtained by holding an inventory corresponding to the inventory quantity c (1) to c (6) obtained as a provisional solution from FIG. 6A according to the flowchart of FIG. It can be seen that there is no possibility of the plant facility 1 being stopped due to one or more out of stock.

Subsequently, a scenario in which the inventory quantity correction process is executed in step S28 of FIG. 2 and the inventory quantities c (1) to c (6) obtained as provisional solutions according to the flowchart of FIG. First, as a first scenario for correcting the provisional solution in step S28 of FIG. 2, the increase / decrease amount Δc (j) (1 ≦ j ≦ J) of the stock quantity c (j) (1 ≦ j ≦ J) from the provisional solution. Consider a case in which the number of stocks c (jq) of spare parts E (jq) that maximizes the rate of change of the total cost of the purchase cost O _j ^c and the inventory management cost Q _j ^c with respect to In this case, in the numerical table of FIG. 6B, when the inventory quantity c (j) is reduced by one from the provisional solution obtained in step S27 of FIG. 2, the total cost of the purchase cost O _j ^c and the inventory management cost Q _j ^c is The largest decrease is E (4). Specifically, if c (4) is reduced from 3 as the provisional solution to 2, the total cost of the purchase cost O _j ^c and the inventory management cost Q _j ^c is reduced by 1193,000 yen. However, as is clear from the numerical table of FIG. 6A, when c (4) is reduced from 3 as the provisional solution to 2, the plant stop time increases from 0 hour to 2 hours. Therefore, in the case of this first scenario, it is understood that spare parts for reducing the inventory should not be selected on the basis of the decrease amount of the purchase cost O _j ^c and the inventory management cost Q _j ^c .

Subsequently, as a second scenario for correcting the provisional solution in step S28 of FIG. 2, the change in the monetary loss P _j ^c with respect to the increase / decrease amount of the inventory number c (j) (1 ≦ j ≦ J) from the provisional solution Consider a case where the inventory quantity c (jp) of the spare part E (jp) having the minimum rate is reduced. In this case, the numerical table of FIG. 6C, the financial loss P _j ^c is reduced smallest when Decrement inventory c a (j) from the provisional solution obtained in step S27 in FIG. 2, E (6 ). Specifically, if c (6) is reduced from 5 which is the provisional solution to 4, the monetary loss P _j ^c increases by 297,000 yen. Moreover, as is apparent from the numerical table of FIG. 6A, the plant stop time remains 0 even if c (6) is reduced from the provisional solution of 5 to 4. Therefore, in the case of this second scenario, it can be seen that it is reasonable to select a spare part that reduces the stock on the basis of the decrease amount of the monetary loss P _j ^c .

Next, an overview of a plant maintenance planning method according to some embodiments of the present invention will be described with reference to FIGS. In the maintenance planning method for plant equipment 1 according to some embodiments of the present invention, first, the combination of the respective inventory numbers c (j) of plural types of spare parts E (j) (1 ≦ j ≦ J) The inventory quantity condition setting step for setting the inventory quantity condition is executed. In an exemplary embodiment, in the inventory quantity condition setting step, the inventory quantity c (j) of each of the plurality of types of spare parts E (j) (1 ≦ j ≦ J) is obtained according to the flowchart shown in FIG. May be. In addition, in this embodiment, a combination of each stock quantity c (j) of a plurality of types of spare parts E (j) (1 ≦ j ≦ J) may be set as the stock quantity condition. Subsequently, in the maintenance planning method, a maintenance menu candidate generation step for determining a plurality of maintenance menu candidates m _k (1 ≦ k ≦ K) (see FIG. 7) of the plant equipment 1 based on the inventory quantity condition. Executed.

FIG. 7 shows an example of a maintenance menu set selected by the maintenance planning method. Maintenance menu set M shown in FIG. 7 is one or more combinations of one or more maintenance menu candidate m _k. In FIG. 7, optional maintenance menu candidates included in the maintenance menu set M are maintenance menu candidates m ₁ , m ₂ , m ₃ , m ₄ , and m ₅ . In the following description regarding the present embodiment, the standard maintenance menu m ₀ will be described on the assumption that it is a maintenance menu that must be performed at least for the maintenance of the plant equipment 1. Further, optional plurality of maintenance menu candidate m ₁ ~m _K, with the exception of the standard maintenance menu m _0, in order to improve the reliability of the plant equipment 1, which is optionally implemented in the form to be added to the standard maintenance menu m ₀ The description will be made assuming that the maintenance menu is. Depending on each of the plurality of (K) maintenance menu candidates m _{1 to} m _K , what type of maintenance work item and which type of maintenance work item for any of the components D1, D2,. Is shown.

In the present embodiment, the entire plant operating time up to the plant cancellation point is divided into a plurality of periods (for example, a first period to an nth period). In other words, the entire operation period of n years until the plant equipment cancellation period is divided into short-term maintenance periods τ _i (1 ≦ i ≦ n) every year. Evaluated for each short-term maintenance period. However, in the present embodiment, the entire operation period may be divided into other lengths of short-term maintenance periods such as every three months or every six months, or non-uniform lengths of short-term maintenance periods.

Subsequently, in the maintenance planning method, an operation rate change calculating step of calculating the change ΔA _k of the operation rate of the plant equipment 1 depending on whether or not a plurality of maintenance menu candidates m _k (1 ≦ k ≦ K) is performed is executed. Is done. Subsequently, in the maintenance planning method, a change in profit obtained by the operation of the plant equipment 1 depending on whether or not each maintenance menu candidate m _k (1 ≦ k ≦ K) is executed based on the change ΔA _k in the operation rate. A profit change calculating step for calculating ΔPc _k is executed. Subsequently, in the maintenance planning method, at least one of a plurality of combinations of maintenance menu candidates m _k (1 ≦ k ≦ K) satisfying at least one constraint condition is determined based on the change in profit ΔPc _k. A selection step for selecting one combination (maintenance menu set) M is executed.

As described above, in the maintenance planning method, not only the maintenance cost and the damage cost caused by the plant stoppage are suppressed, but also the profit expected to be obtained by the operation of the plant equipment 1 based on the expected improvement in the plant operation rate. The appropriate combination (maintenance menu set) M of the maintenance menu m _k (1 ≦ k ≦ K) can be rationally determined in consideration of the result of evaluating the above. As a result, in the maintenance planning method, it is possible to rationally determine a combination of maintenance menus that are sufficiently expected to improve profits obtained from the improvement of the plant operation rate. As a result, in the maintenance planning method described above, the combination of maintenance menu candidates (maintenance menu set) M ′ is selected according to the improvement effect of customer profits when individual maintenance menu candidates m _k (1 ≦ k ≦ K) are implemented. You can choose appropriately.

  In an exemplary embodiment, the maintenance planning method for the plant equipment 1 described above with reference to FIGS. 1 to 6 may be implemented using the computer system 20 shown in FIGS. 8 to 10. In FIG. 4, the computer system 20 may be configured as a system in which the maintenance plan server 100 a, the RAM analysis device 210, the estimation system 220, and the user terminal 230 are interconnected so as to be communicable via the local area network 240. Good. The RAM analyzer 210 and the estimation system 220 may include databases 210a and 220a, respectively, in order to store data managed by the RAM analyzer 210 and the estimation system 220.

  The user terminal 230 is used as an input means for a user to input information and commands to the maintenance plan server 100a, the RAM analysis device 210, and the estimation system 220. The user terminal 230 is also used as output means for displaying output information from the maintenance plan server 100a, the RAM analyzer 210, and the estimation system 220 on the screen.

  When the combination of one or more maintenance menu candidates mk (0 ≦ k ≦ K) is input from the outside, the RAM analyzer 210 determines the device failure rate of the component devices D1 to D (J) constituting the plant facility 1 and The expected operating rate of the entire plant is calculated based on the failure connection between the component devices D1 to D (J). As shown in FIG. 6, the database 210 a included in the RAM analyzer 210 stores information necessary for calculating the expected operating rate of the entire plant by RAM analysis according to a given combination of maintenance menus. For example, the database 210a included in the RAM analyzer 210 stores data representing failure rate curves, failure rate weighting factors, and the like for each component device D (j) (1 ≦ j ≦ J) as shown in FIG. . The database 210a stores a reliability block diagram in the plant facility 1 and the like.

  The estimation system 220 outputs an estimation result of maintenance costs (including preventive maintenance costs) for each of the plurality of maintenance menu candidates mk (0 ≦ k ≦ K) to the maintenance plan server 100 and the user terminal 230. Further, the estimation system 220 manages information for estimating a maintenance cost for each maintenance menu candidate in the database 220a regarding the maintenance of the plant facility 1. The information managed in the database 220a includes the types of inspections, repairs and preventive maintenance performed on each component device D (j) (1 ≦ j ≦ J), the cost required for these, necessary tools, and required man-hours. , Information on necessary parts, required number of necessary parts and inventory quantity of necessary parts, and failure rate reduction amount of each component device D (j) when various repair items and preventive maintenance items are implemented (see FIG. 6) .

  On the estimation system 220, the person in charge of the device may perform cost estimation of the maintenance menu candidate for each device (for each of the component devices D1 to D (J)). The estimation result may include a detailed estimate including the type, quantity, and effect (failure rate reduction amount and MTTR reduction amount for each component device) of inspection items, repair items, and preventive maintenance items. The estimation system 220 displays an input form for inputting information on the screen of the user terminal 230, and the input form can be edited according to the estimated years and the number of plant systems related to various long-term maintenance projects of the plant equipment 1. It may be. In addition, the input form may be mounted so that a human error can be prevented by having a function of checking an input error or an input omission.

Information necessary for the estimation system 220 to generate an estimation result of the maintenance cost required for each execution of the maintenance menu candidates m _k (0 ≦ k ≦ K) is input to the input form. In addition, information for newly creating or updating information stored in the database 220a in FIG. 8 is input to the input form. The above estimation result calculated by the estimation system 220 based on the information entered by each device person in charge from the input form may be notified to the project manager after being finally approved through the approval route designated in advance. Good. The estimation system 220 automatically generates a parts list including spare parts and replacement parts necessary for executing each of the maintenance menu candidates m _k (0 ≦ k ≦ K) from information input by the person in charge of each device. You may make it produce | generate. In addition, the estimation system 220 automatically aggregates the maintenance cost estimation results for each maintenance menu candidate obtained from information input by each device person in charge (for each of the configuration devices D1 to D (J)). Then, the maintenance cost of the whole plant when the maintenance menu candidate m _k (0 ≦ k ≦ K) is executed is calculated.

In response to a request from the user via the user terminal 230, the maintenance plan server 100 sends a plurality of maintenance menu candidates m _k (0 ≦ k ≦ K) and a preventive maintenance cost PMC for each maintenance menu candidate from the estimation system 220. Receive the estimate results for. Subsequently, the maintenance plan server 100 selects and outputs an appropriate maintenance menu set M ′ to the user terminal 230 according to the procedure described above with reference to FIGS.

  The detailed internal configuration of the maintenance plan server 100 will be described below with reference to FIG. The maintenance plan server 100 includes a CPU 110, a main memory 120, and an interface 130. The CPU 110 reads and executes a computer program stored on the main memory 120 in order to execute the maintenance planning method described above with reference to FIGS. The interface 130 provides a communication path for exchanging data and control signals among the CPU 110, the main memory 120, and the local area network 240. A plurality of program modules or functions constituting the computer program may be read from the main memory 120 by the CPU 110 and executed as the functional modules 111 to 119. Hereinafter, the flow of operations when the above-described maintenance planning method is executed by the above-described functional modules 111 to 119 will be described with reference to FIG. The input / output unit 111 functions as a functional module for the above-described functional modules 112 to 119 to exchange data, control commands, and the like with the main memory 120, the database 210, and the control console 220.

First, the flowchart of FIG. 10 starts from step S00, and a plurality of maintenance menu candidates m _k (0 ≦ k ≦ K) are generated. Specifically, first, according to the flowchart shown in FIG. 2, the number of stocks c (j) of a plurality of types of spare parts E (j) (1 ≦ j ≦ J) may be obtained as follows. For example, the input / output unit 111 illustrated in FIG. 9 calls the unnecessary stock determination unit 112 and relates to the equipment component D (j) (1 ≦ j ≦ J) and the spare part E (j) (1 ≦ j ≦ J). Pass information and other information associated with them. Subsequently, the unnecessary inventory determination unit 112 executes steps S21 to S26 of FIG. 2 to determine whether or not inventory is necessary for each of the plurality of types of device component parts D (j) (1 ≦ j ≦ J). The inventory quantity c (j) of the equipment component D (j) (j = j1,..., Jk) determined to be out of stock is set to zero. At that time, the unnecessary stock determination unit 112 receives the recommended stock value SR _j calculated for each of the plurality of types of device components D (j) (1 ≦ j ≦ J) from the recommended stock level calculation unit 119. To determine whether or not inventory is required for each of the device component parts D (j) (1 ≦ j ≦ J). Subsequently, the provisional inventory quantity determination unit 113 executes step S27 of FIG. 2 to calculate a provisional solution of the inventory quantity c (j) for each of the device component parts D (j) (j ≠ j1,..., Jk). To do. Subsequently, the stock quantity initial condition determining means 114 executes step S28 of FIG. 2, and the stock quantity c () obtained as a provisional solution for each of the plurality of types of spare parts E (j) (1 ≦ j ≦ J). j) (1 ≦ j ≦ J) is corrected to obtain a combination of c (j) (1 ≦ j ≦ J) that satisfies a predetermined constraint condition.

Subsequently, the execution of the flowchart of FIG. 10 proceeds to step S11, and the maintenance menu candidate generation unit 115 of FIG. 9 calculates the number of stocks calculated for each of a plurality of types of spare parts E (j) (1 ≦ j ≦ J). The combination of c (j) is set as the inventory quantity condition. Subsequently, based on the inventory quantity condition, a plurality of maintenance menu candidates m _k (1 ≦ k ≦ K) of the plant facility 1 are determined. At that time, the maintenance menu candidate generation means 115 communicates with the RAM analysis device 210 and the estimation system 220, and a plurality of maintenance menu candidates m _k (0 ≦ 0) based on the information stored in the databases 210a and 220a in FIG. k ≦ K).

When the maintenance menu candidate generation means 115 generates a plurality of maintenance menu candidates m _k (0 ≦ k ≦ K) using the information stored in the databases 220a and 220b, the process proceeds to step S01, and the standard maintenance menu An evaluation of m ₀ is performed. More specifically, in step S01, to determine the execution subject devices and implementation time as maintenance items to be included in the standard maintenance menu m _0. The decision, maintenance menu set candidate selection unit 116, trial and error to calculate maintenance items to be performed, exemplary target device, the reference operation rate A _b of the plant equipment 1 while variously changing the implementation period, the reference operation You may make it complete | finish when the rate _Ab becomes an appropriate value. Subsequently, in step S02, it is determined whether or not a constraint condition that the cost required for the plant maintenance work is within the operation budget is imposed. If the constraint condition is imposed, the process proceeds to step S05 and imposed. If not, the process proceeds to step S03.

In step S03, each of a plurality of optional maintenance menu candidates m _{1 to} m _K that may be added to the standard maintenance menu m ₀ is evaluated. Specifically, in step S03, the following two steps are performed. As a first stage process, the maintenance menu set candidate selecting means 116 adds the standard maintenance menu m ₀ to each of the maintenance menu candidates m _k (1 ≦ k ≦ K). The operating rate change index ΔA _k ⁽ⁱ⁾ (1 ≦ k ≦ K, 1 ≦ i ≦ n) is calculated. Subsequently, as the processing of the second stage, the maintenance menu set candidate selection unit 116, based on the reference operation rate _{A b} and uptime change index ^{_{ΔA k (i) (1 ≦}} k ≦ K, 1 ≦ i ≦ n) Then, when each maintenance menu candidate m _k (1 ≦ k ≦ K) is executed, a change Pc _k (1 ≦ k ≦ K) of the first profit obtained by the operation of the plant facility 1 is calculated.

Subsequently, when the execution of step S03 ends, the process proceeds to step S04. In step S04, one or more combinations (one or more maintenance menu candidates m _k) based on the change Pc _k of the first profit calculated for each maintenance menu candidate m _k (1 ≦ k ≦ K) ( Maintenance menu set) M ′ is selected. Specifically, in step S04, maintenance menu set candidate selection means 116 performs the following three steps. First, step S04A is executed as the first stage process. In step S04A, selected from among a plurality of maintenance menu set _{M h (1 ≦ h ≦ H} ), the constraint condition is satisfied maintenance menu set M _.lambda.1 ~M _{[lambda] s} of plant expected operating rate A exceeds the target operation rate _{A g} Is done. In step S04A, the profit Pc _(h) obtained by the plant operation when the maintenance menu sets M _{λ1 to} M _λs are respectively executed is calculated based on the first profit change Pc _k (1 ≦ k ≦ K). calculate. In an exemplary embodiment, if each maintenance menu candidate included in the maintenance menu set M _h is m _k (k = ε1, ε2,..., Εq), m _k (k = ε1, ε2,. revenue Pc _(h) is obtained by summing the changes Pc _k of the first revenue corresponding for all.

Subsequently, step S04B may be executed as a second-stage process. Step S04B is an optional additional process for recalculating the revenue so that the revenue obtained from the plant operation is more appropriately evaluated when the maintenance menu sets M _{λ1 to} M _λs are executed. Execution of this step may be omitted. Note that the recalculated revenue when the maintenance menu sets M _{λ1 to} M _λs are executed is referred to as the second revenue for the maintenance menu sets M _{λ1 to} M _λs . Subsequently, step S04C, which is an optional additional process, may be executed as the third stage process. In step S04C, based on the second revenue evaluated for each of the maintenance menu set _M λ1 ~M λs, one or more suitable maintenance menu set M _.sigma.1 ~M _{[sigma] s} from the maintenance menu set M _.lambda.1 ~M _{[lambda] s} You may choose.

If it is determined in step S02 that a constraint condition that the cost required for the plant maintenance work is within the operation budget is imposed, the process proceeds to step S05. In step S05, each of a plurality of optional additional maintenance menu candidates m _{1 to} m _K that may be added to the standard maintenance menu m ₀ is evaluated. Specifically, in step S05, the following three steps are performed. The processes of the first stage and the second stage are the same as the processes of the first stage and the second stage in S03. In the third stage of processing, the cost effectiveness when each maintenance menu candidate m _k (1 ≦ k ≦ K) is implemented is evaluated for each maintenance menu candidate m _k (1 ≦ k ≦ K).

Subsequently, when the execution of step S05 ends, the process proceeds to step S06. In step S06, based on a change Pc _k of the first revenue calculated for each of the maintenance menu candidate _{m k (1 ≦ k ≦ K} ), one or more maintenance menu candidate _m k respectively (1 ≦ k ≦ K) One or more appropriate maintenance menu sets M ′ are selected from one or more combinations (maintenance menu sets) M _h (1 ≦ h ≦ H). Specifically, in step S06, maintenance menu set candidate selection means 116 performs the following three steps. First, step S06A is executed as the first stage process. In step S06A, a cost that is required for plant maintenance is determined in advance from the plurality of maintenance menu sets M _h (1 ≦ h ≦ H) that satisfies the constraint that the expected plant operating rate exceeds the target operating rate. Maintenance menu sets M _{λ1 to} M _λs that satisfy the constraint that they fall within the operational budget are selected. Further, in step S06A, the profit obtained by the plant operation when each of the maintenance menu sets M _{λ1 to} M _λs is executed is calculated based on the change Pc _k of the first profit. Subsequently, step S06B may be executed as the second stage process, and step S06C may be executed as the third stage process. Since the processing content of step S06B and step S06C is the same as that of step S04B and step S04C, description is abbreviate | omitted.

When the execution of step S04 ends, the execution of the flowchart of FIG. 10 proceeds to step S09. In step S09, one or more maintenance menu set candidates consisting of a combination of at least one maintenance menu candidate among a plurality of maintenance menu candidates m _k (1 ≦ k ≦ K) are determined by the constraint condition satisfaction determination unit 117 of FIG. The following processing is performed for each. That is, a constraint condition determining step is performed for determining whether or not the maintenance constraint condition is satisfied for each of the maintenance menu set candidates M _{λ1 to} M _λs (or maintenance menu set candidates M _{σ1 to} M _σs ). Specifically, in step S09, when any one of the maintenance menu sets M _{λ1 to} M _λs selected in step S04 is executed, whether or not the expected operating rate of the plant facility 1 achieves the target operating rate. If the target operating rate is determined, the execution of the flowchart of FIG. If it is determined in step S09 that the target operating rate has not been achieved, the execution of the flowchart of FIG. 10 proceeds to step S10.

When the execution of step S06 ends, the execution of the flowchart of FIG. 10 proceeds to step S08. Also in step S08, one or more maintenance menu set candidates composed of a combination of at least one maintenance menu candidate among a plurality of maintenance menu candidates m _k (1 ≦ k ≦ K) by the constraint condition satisfaction determination unit 117 of FIG. For each of M _{λ1 to} M _λs , a constraint condition determination step for determining whether or not the maintenance constraint condition is satisfied is executed. Specifically, in step S08, when any one of the maintenance menu sets M _{λ1 to} M _λs selected in step S06 is performed, the expected operating rate of the plant facility 1 achieves the target operating rate, and It is determined whether or not the maintenance cost required to execute any one of the maintenance menu sets M _{λ1 to} M _λs falls within the budget. If it is determined in step S08 that the target operating rate has been achieved and the maintenance cost is within the budget, the execution of the flowchart of FIG. If it is determined in step S08 that the target operating rate has not been achieved or the maintenance cost does not fall within the budget, execution of the flowchart in FIG. 10 proceeds to step S10.

Step S10 is executed by the inventory quantity correcting unit 118 after the inventory quantity correcting unit 118 of FIG. 9 receives all the maintenance menu set candidates M _{λ1 to} M _λs from the constraint condition satisfaction determining unit 117. In step S10, when the maintenance constraint condition is not satisfied for all the maintenance menu set candidates M _{λ1 to} M _λs , the inventory quantity c (j) of one or more spare parts E (j) in the inventory quantity condition previously set in step 11 is established. ) To execute the inventory quantity condition correction step. Specifically, in step S10, if all the maintenance menu set candidates M _{λ1 to} M _{λs do not satisfy} the first condition (condition that the maintenance cost necessary for long-term plant maintenance falls within a predetermined budget), at least In step 11, the purchase cost O _j ^c (1 ≦ j ≦ J) and the inventory management cost Q _j ^c (1) for the increase / decrease amount Δc (j) (1 ≦ j ≦ J) of the inventory number from the previously set inventory number condition ≦ j ≦ J) or the spare part E (jf) that maximizes the third rate of change of the total cost, and the increase / decrease amount Δc (j) (1 ≦ j ≦ J) of the inventory quantity from the previous inventory quantity condition The spare part E (jg) having the smallest fourth change rate of the monetary loss P _j ^c (1 ≦ j ≦ J) or the spare part E (the ratio of the fourth change rate to the third change rate being the smallest The inventory quantity c (jh) of jh) is reduced.

As described above, in step S10, the inventory quantity c (jf) can be reduced for the spare part E (jf) that can most effectively reduce the cost required for inventory procurement and / or inventory management. Further, in step S10, when the stock quantity c (j) (1 ≦ j ≦ J) is reduced by a predetermined amount, a monetary loss P _j ^c (1 ≦ j ≦ J) that occurs due to a plant stoppage or the like when the stock is out of stock. It is possible to reduce the stock quantity c (jg) for the spare part E (jg) whose increase width is as small as possible. Further, in step S10, when the stock quantity c (j) (1 ≦ j ≦ J) is reduced by a predetermined amount, a monetary loss P _j ^c (1 ≦ j ≦ J) that occurs due to a plant stoppage or the like when the stock is out of stock. The number of stocks c (jh) can be reduced for spare parts E (jh) that can reduce the cost of inventory procurement and / or inventory management most effectively. Thus, the possibility of finding the maintenance menu set candidate M that satisfies the maintenance constraint condition can be increased by correcting the inventory quantity condition.

In step S10, if the second condition for all maintenance menu set candidate _M λ1 ~M λs (the expected availability of the plant equipment when carrying out the maintenance menu set candidate is not less than the target utilization rate) it is not satisfied In step S11, the amount of increase / decrease in the inventory quantity from the inventory quantity condition set last time Δc (j) (1 ≦ j ≦ J) with respect to the increase in the operating rate of the plant equipment 1 due to the inventory of the spare part E (je) The inventory quantity c (jj) of the spare part E (je) having the maximum change rate is increased.

  As described above, in step S10, the plant quantity c (j) (1 ≦ j ≦ J) is increased or decreased for any one or more of the plurality of types of spare parts E (j) (1 ≦ j ≦ J). The inventory quantity c (ji) can be adjusted for the most effective spare part E (jb) in order to satisfy the condition that the sum of the operating rate improvement widths of the equipment 1 achieves the target value. Thus, the maintenance menu set candidate M that satisfies the maintenance constraint condition (second condition that the expected operating rate of the plant equipment when the maintenance menu set candidate is executed is equal to or higher than the target operating rate) can be found by correcting the inventory quantity condition. Can increase the sex.

  When the process of changing the inventory quantity c (j) (1 ≦ j ≦ J) of one or more spare parts E (j) in the inventory quantity condition previously set in step 11 is completed, the inventory quantity c ( j) After setting (1.ltoreq.j.ltoreq.J) as a new inventory quantity condition, the execution of the flowchart in FIG.

DESCRIPTION OF SYMBOLS 1 Plant equipment 2 Boiler 3 Furnace 4 Furnace wall 5 Burner 6 Air nozzle 7 Flue 8 Superheater 9 Reheater 10 Economizer 11 Drum 12 Fuel supply means 13 Air supply means 13a Pushing ventilator 13b Wind box 13c Air duct 13d Heat exchanger 14 exhaust gas line 14a exhaust gas duct 14b denitration device 14c electrostatic precipitator 14d induction ventilator 14e desulfurization device 14f chimney 20 computer system 100 maintenance plan server 111 input / output unit 112 unnecessary inventory determination calculation means 113 provisional inventory quantity determination means 114 provisional inventory number initial condition Determination means 115 Maintenance menu candidate generation means 116 Maintenance menu set candidate selection means 117 Restriction condition satisfaction determination means 118 Inventory quantity correction means 119 Inventory recommendation degree calculation means 120 Main memory 130 Interface 210 RAM analysis device 210a Base 220 quotation system 220a database 230 user terminal 240 local area network

Claims (14)

A maintenance planning method for plant equipment,
For each of a plurality of types of spare parts held for each of a plurality of types of equipment components of the plant facility, the purchase cost of the spare parts determined according to the number of the inventory of the spare parts is calculated for each number of the inventory. Purchase cost determination step,
For each of the plurality of types of spare parts, an inventory management cost determination step for calculating, for each inventory quantity, an inventory management cost of the spare parts determined according to the inventory quantity of the spare parts;
For each of the plurality of types of spare parts, a loss calculating step for calculating a monetary loss due to the plant equipment being shut down or being reduced in capacity due to out of stock of the spare parts for each inventory quantity;
For each of the plurality of types of spare parts, a provisional inventory quantity determination step for determining a provisional solution of the inventory quantity based on the purchase cost, the inventory management cost, and the monetary loss;
A maintenance planning method for plant equipment, comprising: For each of one or more parts among the plurality of types of equipment component parts, the degree of reduction in the capacity of the plant facility when the parts fail, the failure rate of the parts, and the spare parts for the parts An inventory necessity determination step for determining the necessity of inventory of each of the parts based on the delivery date;
In the provisional inventory number determination step, the provisional solution of the inventory number is determined to be zero for the spare part for the part that is determined to be unnecessary in the inventory necessity determination step.
The plant facility maintenance planning method according to claim 1, wherein: When at least one of the following conditions (a) or (b) is satisfied, the method further comprises an inventory quantity correction step of correcting the inventory quantity of the provisional solution for at least one of the plurality of types of spare parts. The maintenance plan method of the plant equipment of Claim 1 or 2.
(A) The sum of the operating efficiency improvement widths of the plant equipment by holding each of the plurality of types of spare parts by the number of stocks of the provisional solution is less than the target operating capacity improvement amount of the plant equipment.
(B) The total sum of the purchase cost and the inventory management cost for each of the plurality of types of spare parts exceeds the inventory-related budget.   The inventory quantity correction step increases at least the inventory quantity of the spare part having a maximum rate of change in the operating rate improvement range with respect to an increase / decrease amount of the inventory quantity from the provisional solution. The maintenance planning method for the plant equipment described.   In the inventory quantity correction step, at least the spare part that maximizes the first change rate of the purchase cost, the inventory management cost, or the total cost with respect to the increase / decrease amount of the inventory quantity from the provisional solution, from the provisional solution The number of stocks of the spare part in which the second change rate of the monetary loss relative to the increase / decrease amount of the stock number is the minimum, or the ratio of the second change rate to the first change rate is the minimum The plant facility maintenance planning method according to claim 3 or 4, wherein the plant facility maintenance plan is reduced. In the loss calculation step,
For each of the plurality of types of spare parts, calculate the stop time or the capacity reduction time of the plant equipment due to the out of stock of the spare parts for each stock quantity,
The calculated loss time of the plant equipment or the reduced capacity time is multiplied by the lost profit per unit time caused by the stop of the plant equipment or the reduced capacity, and the monetary loss is calculated for each inventory quantity. The plant facility maintenance planning method according to claim 1, wherein the plant facility maintenance planning method is calculated. In the provisional inventory quantity determination step,
Regarding the periodic replacement parts among the plurality of types of equipment component parts, the period from the inventory holding examination reference time to the next periodic replacement time is the same as or longer than the preparation period determined according to the delivery date of the periodic replacement parts And determining a provisional solution for the number of inventory based on the purchase cost, the inventory management cost and the monetary loss for the periodic replacement part,
7. The system according to claim 1, wherein when the period is shorter than the preparation period, the number of the periodic replacement parts in stock is determined to be equal to or greater than the number of the periodic replacement parts necessary for the periodic replacement work. The maintenance plan method of the plant equipment as described in the item. A maintenance menu candidate generation step for generating a plurality of maintenance menu candidates for the plant equipment based on the inventory quantity determined by the provisional inventory quantity determination step for each of the plurality of types of spare parts;
A step of calculating a change in the operating rate of the plant equipment depending on whether or not each of the maintenance menu candidates is implemented; an operating rate change calculating step;
A profit change calculating step for calculating a change in profit obtained by operating the plant equipment based on whether or not each of the maintenance menu candidates is implemented based on the change in the operation rate;
A selection step of selecting at least one of the combinations satisfying at least one of the plurality of combinations of the maintenance menu candidates based on the change in the revenue;
The plant facility maintenance planning method according to any one of claims 1 to 7, further comprising: An inventory quantity condition setting step for setting an inventory quantity condition that is a combination of the inventory quantities of each of the plurality of types of spare parts;
A maintenance menu candidate generation step for determining a plurality of maintenance menu candidates for the plant equipment based on the inventory quantity condition;
A constraint condition determination step for determining whether or not a maintenance constraint condition is satisfied for each of one or more maintenance menu set candidates including a combination of at least one maintenance menu candidate among the plurality of maintenance menu candidates;
The plant facility maintenance planning method according to any one of claims 1 to 8, further comprising:   The maintenance constraint condition is the first condition whether or not the maintenance cost necessary for the execution of the maintenance menu set candidate is within a maintenance budget, or the expected operation of the plant equipment when the maintenance menu set candidate is executed The plant facility maintenance planning method according to claim 9, comprising at least one of a second condition whether the rate is equal to or higher than a target operating rate.   When the maintenance constraint condition is not satisfied for all the maintenance menu set candidates, the inventory quantity condition correcting step of changing the inventory quantity of the one or more spare parts in the previous inventory quantity condition is further provided. The maintenance plan method of the plant equipment of Claim 9 or 10. The maintenance constraint condition includes a first condition as to whether or not a maintenance cost necessary for executing the maintenance menu set candidate is within a maintenance budget,
In the inventory quantity condition correction step,
If the first condition is not satisfied for all the maintenance menu set candidates, at least a third of the purchase cost, the inventory management cost, or the total cost with respect to the increase / decrease amount of the inventory quantity from the previous inventory quantity condition The spare part having the maximum rate of change, the spare part having the smallest fourth change rate of the monetary loss with respect to the increase / decrease amount of the stock quantity from the previous inventory quantity condition, or the third change ratio The plant equipment maintenance planning method according to claim 11, wherein the number of spare parts in stock having a minimum ratio of the fourth rate of change to the plant is reduced. The maintenance constraint condition includes a second condition as to whether or not an expected operation rate of the plant facility when the maintenance menu set candidate is implemented is equal to or higher than a target operation rate,
In the inventory quantity condition correction step,
If the second condition is not satisfied for all the maintenance menu set candidates, the increase in the operating rate of the plant equipment due to the inventory of the spare parts with respect to the increase / decrease amount of the inventory quantity from the previous inventory quantity condition 13. The plant facility maintenance planning method according to claim 11 or 12, wherein the number of spare parts in stock having the highest rate of change is increased. In a computer system having a maintenance plan server for formulating a maintenance plan for plant equipment, the maintenance plan server includes:
For each of a plurality of types of spare parts held for each of a plurality of types of equipment components of the plant facility, the purchase cost of the spare parts determined according to the number of the inventory of the spare parts is calculated for each number of the inventory. Purchase cost determination means,
For each of the plurality of types of spare parts, inventory management cost determining means for calculating the inventory management cost of the spare parts determined according to the inventory quantity of the spare parts for each inventory quantity;
For each of the plurality of types of spare parts, a loss calculating means for calculating a monetary loss due to the plant equipment being shut down or being reduced in capacity due to out-of-stock of the spare parts, for each number of stocks;
For each of the plurality of types of spare parts, provisional inventory quantity determining means for determining a provisional solution of the inventory quantity based on the purchase cost, the inventory management cost, and the monetary loss;
A computer system comprising:

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