Production planning system and production planning method

Abstract

To provide a production planning system which can generate a production plan which allows maintenance work to be performed while keeping a target production quantity.SOLUTION: The production planning system makes a production plan for a production line including a tact time calculated by dividing an operating time of the production line by a target production quantity and comprises a determination unit which determines whether a detection value indicative of performance of a facility for use in the production line exceeds a reference value being a predictive value of the detection value at a reference time resulting from subtracting a grace time from a predictive time at which it is predicted that maintenance work for the facility will be necessary or not, an acquisition unit which acquires a maintenance work time required for the maintenance work if the determination unit determines that the detection value exceeds the reference value, a calculation unit which uses the grace time and the maintenance work time to calculate a reduction time of the tact time for generating the maintenance work time within the grace time, and a change unit which changes a previous production plan to a production plan which uses a reduced tact time obtained by subtracting the reduction time from the tact time.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a production plan formulation system and a production plan formulation method.

Background Art

[0002] Conventionally, in a production line where a plurality of areas where processes are carried out are arranged in a line for production, there is a technique for performing production efficiently (for example, Patent Document 1). Patent Document 1 discloses a technique of arranging display means used for an inspection process in an area of a surplus process where time remains when the time required for work is subtracted from the tact time among a plurality of processes.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when a defect occurs in the equipment used in the production line, it is necessary to perform maintenance work on the equipment. When the equipment with the defect is the equipment used in the above-mentioned surplus process, the maintenance work can be performed using the surplus time. However, there are cases where the equipment with the defect is not the equipment used in the above-mentioned surplus process, or the maintenance work cannot be completed within the surplus time. In such a case, it is necessary to stop the production line to perform the maintenance work, and there is a risk that the target production quantity cannot be produced.

Means for Solving the Problems

[0005] The present disclosure can be realized in the following forms. According to one aspect of the present disclosure, a production plan formulation system is provided. The production plan formulation system formulates a production plan for a production line, the production plan including a tact time calculated by dividing the operating time of the production line by the target production quantity, and determines whether a detected value indicating the performance of equipment used in the production line exceeds a reference value that is a predicted value of the detected value at a reference time obtained by subtracting a lead time from a predicted time at which maintenance work for the equipment is required. When the determination unit determines that the detected value exceeds the reference value, an acquisition unit acquires the maintenance work time required for the maintenance work, and a calculation unit calculates a reduction time of the tact time for generating the maintenance work time within the lead time using the lead time and the maintenance work time. When the reduced tact time obtained by subtracting the reduction time from the tact time is less than or equal to the cycle time, the calculation unit calculates, as the reduction time, a time obtained by subtracting the cycle time from the tact time. The production plan formulation system further includes a change unit that changes the production plan. When the reduced tact time is longer than the cycle time, the change unit changes the previous production plan to a production plan using the reduced tact time. When the reduced tact time is less than or equal to the cycle time, the change unit changes the previous production plan to a production plan using the reduced tact time and including a decrease in the target production quantity.

[0006] (1) According to one aspect of the present disclosure, a production plan formulation system is provided. This production plan formulation system formulates a production plan for a production line, including a tact time calculated by dividing the operating time of the production line by the target production quantity, and determines whether a detected value indicating the performance of equipment used in the production line exceeds a reference value, which is a predicted value of the detected value at a reference time obtained by subtracting a lead time from a predicted time when maintenance work on the equipment is predicted. When the determination unit determines that the reference value has been exceeded, an acquisition unit acquires the maintenance work time required for the maintenance work, and a calculation unit calculates a reduction time of the tact time for generating the maintenance work time within the lead time using the lead time and the maintenance work time. A change unit changes the production plan up to now to the production plan using the reduced tact time obtained by subtracting the reduction time from the tact time. According to this aspect, it is possible to predict maintenance work in advance and, when maintenance work is required, perform the maintenance work without reducing the target production quantity by shortening the tact time. (2) In the production plan formulation system of the above aspect, when the reduced tact time is shorter than the cycle time, the change unit may change the production plan up to now to the production plan including a decrease in the target production quantity. According to this aspect, when the reduced tact time is shorter than the cycle time, which is the actual production time per unit, it is possible to change the production plan to include a decrease in the target production quantity. (3) In the production plan formulation system of the above-described form, the production line includes a plurality of the facilities, the buffer time and the maintenance work time are determined in advance for each of the plurality of facilities, and when the determination unit determines that the detected value exceeds the reference value for the plurality of facilities, the calculation unit uses the buffer time of the facility having the shortest buffer time among the plurality of facilities for which the detected value is determined to exceed the reference value and the longest maintenance work time, which is the maintenance work time of the facility having the longest maintenance work time, to calculate the shortening time, and the change unit may set the stop time of the production line for performing the maintenance work of the plurality of facilities within the longest maintenance work time. According to this form, since a plurality of maintenance works can be performed at the stop time of the production line, the maintenance work can be efficiently carried out. (4) In the production plan formulation system of the above-described form, the determination unit can communicate with a storage unit in which prediction data in which a limit value, which is the detected value at the predicted time, the reference value, and the facility are associated is stored, and the determination unit may make a determination using the reference value of the prediction data. According to this form, it is possible to determine whether or not the reference value is exceeded using the prediction data. (5) In the production plan formulation system of the above-described form, further, when the shortened tact time is shorter than the cycle time, an update unit may be provided that updates the reference value so as to be farther from the limit value so that the buffer time becomes longer. According to this form, in the next implementation of the maintenance work, adjustment for shortening the tact time can be made earlier, so the possibility of being able to perform the maintenance work without reducing the target production quantity can be increased. (6) In the production plan formulation system of the above-described form, further, a setting unit may be provided that sets the buffer time longer as the maintenance work time is longer. According to this form, even when the maintenance work time is long, by setting the buffer time long, the possibility of being able to generate the maintenance work time by shortening the tact time without changing the target production quantity can be increased. The present disclosure can also be realized in various forms of a production plan formulation system. For example, it can be realized in the form of a production plan formulation method or the like.

Brief Description of the Drawings

[0007]

Figure 1

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Figure 8

Figure 9

Modes for Carrying Out the Invention

[0008] A. First Embodiment: FIG. 1 is a schematic diagram of a production line 10 and a production planning system 20. FIG. 2 is a block diagram showing the configuration of the production planning system 20. FIG. 3 is a block diagram showing the configuration of a facility F1 which is a belt conveyor. As shown in FIG. 1, the production line 10 performs production using the production plan 81 (FIG. 2) formulated by the production planning system 20. The production line 10 has a plurality of areas for executing each process arranged on the line. The product W is sequentially conveyed to the areas of each process, and each process is performed. In the production line 10, a plurality of facilities F are used. Specifically, the facility F includes, for example, a belt conveyor for conveying the product W, devices such as robots and tools for processing and assembling the product W, workers, devices and workers for inspecting the product, and the like. In the present embodiment, each of the plurality of facilities F is assigned an identification number. When distinguishing each of the plurality of facilities, the identification number is appended after the facility F for description. For example, the facility F1 is the facility F with the identification number "1". In the present embodiment, the production line 10 includes s facilities F from the facility F1 to the facility Fs. The facility F1 is a belt conveyor. The facilities F2 and F4 are workers. The facilities F3, F5, and Fs are devices. In the areas for executing each process, there are areas where workers are arranged and unmanned areas where no workers are arranged and only devices are arranged. In the present embodiment, the production line 10 includes n processes from process 1 to process n.

[0009] The production plan establishment system 20 establishes a production plan 81. During the production period, the production plan establishment system 20 sets the target production quantity per unit production period in order to produce the target total production quantity set using, for example, the number of orders received. The production period is, for example, one month. The unit production period is, for example, one week or one day. Further, the production plan establishment system 20 calculates the takt time by dividing the operating time in the unit production period by the target production quantity in the unit production period. Then, when the calculated takt time is shorter than the cycle time, the production plan establishment system 20 changes the production plan 81 to a production plan in which the target production quantity is decreased so that the takt time is equal to or longer than the cycle time, and updates the production plan 81. Here, the cycle time is the time calculated by dividing the operating time by the actual production quantity. As the value of the cycle time, the actual value of the past cycle time is used. The value of the cycle time varies depending on, for example, the proficiency of the workers. The units of both the takt time and the cycle time are both "seconds". The process by which the production plan establishment system 20 described above establishes the production plan 81 is also referred to as the establishment step.

[0010] The production plan establishment system 20 is realized on a PC. As shown in FIG. 2, the production plan establishment system 20 includes a control unit 21, a display 24, and a keyboard 25. The control unit 21 has a CPU 22 and a memory 23 as a storage unit. Further, the CPU 22 has, as functional units, a determination unit 31, an acquisition unit 32, a calculation unit 33, and a change unit 34. Each functional unit such as the determination unit 31 is realized by executing a program stored in the memory 23. As will be described in detail later, the determination unit 31 determines whether or not a detection value indicating the performance of the facility F exceeds a reference value that is a predicted value of the detection value at a reference time t1 obtained by subtracting a lead time from a predicted time t2 at which it is predicted that maintenance work on the facility F is necessary, using the facility data 82. The acquisition unit 32 acquires the maintenance work time required for the maintenance work. The calculation unit 33 calculates a reduction time of the tact time for generating the maintenance work time within the lead time. The change unit 34 changes the previous production plan 81 to a production plan 81 using a reduced tact time obtained by subtracting the reduction time from the tact time. The memory 23 stores a production plan 81, facility data 82, and prediction data 83. The production plan 81 is the production plan 81 created by the production plan establishment system 20. The facility data 82 and the prediction data 83 are used for predicting maintenance work and the like. The facility data 82 is data indicating the change over time of a detection value indicating the performance of the facility F. The display 24 displays information. The keyboard 25 accepts input of information.

[0011] The production planning system 20 is communicably connected to the equipment F among the plurality of equipment F, that is, the equipment F which is a device excluding workers. Using FIG. 3, the equipment F1 which is a belt conveyor will be exemplified and described. The equipment F1 includes a communication unit 50, a drive unit 51, a roller 52, and a detection sensor 53. The communication unit 50 communicates with the production planning system 20. The roller 52 rotates a conveyor belt (not shown). The drive unit 51 drives the roller 52. The detection sensor 53 is a sensor for detecting the friction coefficient between the roller 52 and the conveyor belt. The communication unit 50 is communicably connected to the drive unit 51 and the detection sensor 53. The drive unit 51 controls the roller 52 so that the conveyance time between the areas of each process becomes the target conveyance time according to the production plan 81 transmitted from the production planning system 20 via the communication unit 50. The detection sensor 53 transmits the detection value of the detection sensor 53 indicating the friction coefficient to the production planning system 20 via the communication unit 50. Note that the information communicated between the production planning system 20 and the equipment F depends on the type of the equipment F. For example, if the equipment F is a screw tightening tool, the torque value in screw tightening is transmitted as a detection value. For example, if the equipment F is a welding robot, the current value in welding is transmitted as a detection value.

[0012] The detection value transmitted from the equipment F to the production planning system 20 indicates the performance of the equipment F and is used as an index for performing maintenance work on the equipment F. For example, when the detection value indicating the friction coefficient of the equipment F1 becomes larger than a limit value described later, maintenance work such as oiling is performed.

[0013] FIG. 4 is a diagram for explaining the equipment data 82 of the equipment F1. The horizontal axis of FIG. 4 is time, and the vertical axis is a detected value indicating the friction coefficient that indexes the performance of the equipment F1. The equipment data 82 is time-series data in which the integrated operation time of the equipment F from the previous maintenance work is associated with the detected value. The equipment data 82 is stored in the memory 23 for each piece of equipment F. The transmission of the data of the production planning system 20 is continuously performed. Specifically, the data is transmitted at a predetermined time interval during the period when the equipment F is operating. When the control unit 21 receives the detected value, it adds the received detected value to the equipment data 82 and updates the equipment data 82.

[0014] For each piece of equipment F, a limit value for performing maintenance work and a reference value for predicting maintenance work are preset. The limit value is used to determine whether it is necessary to perform maintenance work immediately. Specifically, when the detected value exceeds the limit value, for example, an alarm provided in the equipment F sounds and the operation of the equipment F stops. In this case, after the maintenance work is performed by the operator, the operation of the equipment F is restarted.

[0015] As described above, when the detected value exceeds the limit value and the operation of the equipment F stops, the production line 10 stops and the production as per the production plan 81 is not carried out. Therefore, in the present embodiment, a reference value, which is a predicted value of the detected value at the reference time t1 obtained by subtracting the lead time from the predicted time t2 when maintenance work of the equipment F is predicted, is set, and the maintenance work is predicted by comparing the detected value with the reference value. Furthermore, by scheduling the maintenance work in advance, the tact time of the production plan 81 is changed in advance. Thereby, the production of the target production quantity can be carried out.

[0016] For each piece of equipment F, the prediction data 83 is data in which a limit value, a reference value, and a grace period are set. The limit value is a detected value indicating the performance of the equipment F at the prediction time t2. The reference value is a predicted value of the detected value at the reference time t1. Typically, the actual detected value at the reference time t1 is set as the reference value. Thus, when the detected value exceeds the reference value, it can be predicted that the detected value will exceed the limit value after the grace period has elapsed. The prediction data 83 is created using past equipment data 82. Depending on the type of equipment F, whether the detected value increases or decreases as the performance deteriorates varies. For example, in the case of equipment F1, the performance deteriorates as the detected value indicating the friction coefficient increases.

[0017] FIG. 5 is a flowchart of a production plan formulation process for realizing a production plan formulation method. FIG. 6 is a flowchart of a shortened time calculation process. FIG. 7 is a diagram for explaining the changed production plan 81. When the production plan formulation system 20 receives an execution of the production plan formulation process, it executes the production plan formulation process.

[0018] In this embodiment, the production plan formulation process is executed for the equipment F1. The determination unit 31 refers to the prediction data 83 and substitutes the reference value of the equipment F1 into the variable B (step S12). The determination unit 31 substitutes the latest detected value of the equipment data 82 into the variable V (step S14). Since the equipment F1 is equipment F in which the detected value increases as the performance deteriorates, the determination unit 31 determines whether the variable V is greater than the absolute value of the variable B (step S16). When it is determined that the variable V is not greater than the absolute value of the variable B, that is, the variable V is less than or equal to the absolute value of the variable B (step S16: NO), the determination unit 31 repeatedly executes steps S14 and S16 every predetermined time, for example, every few minutes, until it is determined that the variable V is greater than the absolute value of the variable B.

[0019] When it is determined that the variable V is greater than the absolute value of the variable B (step S16: YES), the change unit 34 refers to the production plan 81, substitutes the tact time into the variable T, and substitutes the cycle time into the variable C (step S30). The case where the variable V is determined to be greater than the absolute value of the variable B means that, that is, it is determined that the detection value indicating the performance of the facility F1 exceeds the reference value and the performance of the facility F1 has deteriorated. Step S16 is also called a determination step. The tact time and the cycle time to be substituted are the times set in the production plan 81. The case where the variable V is determined to be greater than the absolute value of the variable B means that it is necessary to perform maintenance work on the facility F1 after the expiration of the grace period.

[0020] The change unit 34 determines whether the variable T is greater than the variable C (step S32). When it is determined that the variable T is not greater than the variable C, that is, the variable T is less than or equal to the variable C (step S32: NO), the change unit 34 changes the previous production plan 81 to a production plan 81 that reduces the target production quantity and incorporates a production line stop (step S70). When the variable T is less than or equal to the variable C, since there is no room to shorten the tact time, the target production quantity is reduced and the operation time is shortened to generate the time for performing the maintenance work. The changed production plan is transmitted to the facility F.

[0021] As shown in FIG. 7, specifically, the production line 10 is planned to stop at the end of the grace period. When the end of the grace period indicated by the arrow is the end of the operating hours on the third operating day, maintenance work is planned at the end of the operating hours on the third operating day. In FIG. 7, the unit production period is one week, and the case where step S70 is performed at the start of operation on the second day is shown. On the day when the maintenance work is carried out, for example, a message indicating that the production line 10 has stopped is displayed on the display 24. Thereby, the operator can know that the production line 10 has stopped. When the maintenance work is scheduled, the conveyance of the product W by the equipment F1 is stopped. Then, the maintenance work of the equipment F1 is carried out by the operator. In this case, although it is necessary to reduce the target production quantity, in order to make up for the reduced production quantity, for example, corresponding measures such as increasing the operating hours after the grace period has elapsed can be taken early. After the execution of step S70, the control unit 21 ends this processing routine.

[0022] As shown in FIG. 5, when the change unit 34 determines that the variable T is larger than the variable C (step S32: YES), the acquisition unit 32 substitutes the maintenance work time of the equipment F1 acquired from the prediction data 83 into the variable M, and substitutes the grace period acquired from the prediction data 83 into the variable P (step S38). Step S38 is also called an acquisition step. When the variable T is larger than the variable C, there is room to shorten the tact time, so this is for performing the shortening time calculation process.

[0023] The calculation unit 33 performs a shortening time calculation process in order to calculate the shortening time of the tact time required to perform the maintenance work time (step S40). Step S40 is also called a calculation step. As shown in FIG. 6, the calculation unit 33 substitutes zero into the variable t indicating the shortening time [seconds] (step S50). The calculation unit 33 increments the variable t (step S52). The calculation unit 33 calculates the total time b indicating the total shortening time in the period until the grace period has elapsed (step S54). Specifically, the total time b is calculated by multiplying the variable t by the target production quantity in the grace period.

[0024] The calculation unit 33 determines whether the total time b is greater than the variable M indicating the maintenance work time (step S56). If it is determined that the total time b is not greater than the variable M, that is, the total time b is less than or equal to the variable M (step S56: NO), the calculation unit 33 determines whether the value obtained by subtracting the variable C from the variable T is the same as the variable t (step S58). If it is determined that the value obtained by subtracting the variable C from the variable T is not the same as the variable t (step S58: NO), since there is room to further shorten the tact time, the calculation unit 33 proceeds to step S52. Then, the calculation unit 33 increments t (step S52) and executes the processing steps after step S54 until it is determined that the total time b is greater than the variable M or the value obtained by subtracting the variable C from the variable T is the same as the variable t.

[0025] If the calculation unit 33 determines that the total time b is greater than the variable M (step S56: YES), it returns the values of the total time b and the variable t (step S60). The value of the variable t when it is determined that the total time b is greater than the variable M is the shortened time of the tact time for generating the maintenance work time within the allowance time. This case is when the maintenance work time can be generated without reducing the target production quantity by shortening the tact time.

[0026] If the calculation unit 33 determines that the value obtained by subtracting the variable C from the variable T is the same as the variable t (step S58: YES), it returns the values of the total time b and the variable t (step S60). This case is when the maintenance work time cannot be generated without reducing the target production quantity even if the tact time is shortened to the cycle time.

[0027] As shown in FIG. 5, the change unit 34 determines whether the total time b of the returned values is greater than the variable M (step S42). If it is determined that the total time b is greater than the variable M (step S42: YES), the change unit 34 changes the current tact time to a tact time obtained by subtracting a variable t indicating a shortening time from the current tact time, and also changes the production plan 81 incorporating the maintenance work plan (step S72). The tact time obtained by subtracting the variable t from the current tact time when it is possible to incorporate the maintenance work by shortening the tact time while maintaining the target production quantity is also referred to as the shortened tact time. That is, in step S72, the change unit 34 changes the current production plan 81 to a production plan 81 using the shortened tact time. By shortening the tact time and the operation time, a time for performing the maintenance work is generated. Step S72 is also referred to as the change step. In order to generate the maintenance work time, in step S70, the target production quantity is decreased and the operation time is shortened, whereas in step S72, the target production quantity is not changed and the tact time is shortened and the operation time is shortened. Thus, by shortening the tact time, it is possible to perform the maintenance work within the allowance time while maintaining the target production quantity.

[0028] The changed production plan is transmitted to the facility F. Thereby, the time interval at which the product W is conveyed from the previous process area to the process area is set shorter. After the execution of step S72, the control unit 21 ends this processing routine.

[0029] When it is determined that the total time b is not greater than the variable M, that is, the total time b is less than or equal to the variable M (step S42: NO), the modification unit 34 decreases the target production quantity, changes the current tact time to a tact time obtained by subtracting a variable t indicating the shortening time from the current tact time, and changes to a production plan 81 incorporating a maintenance work plan (step S74). This case is when the shortened tact time is shorter than the cycle time. That is, in order to generate maintenance work time while maintaining the target production quantity, it is necessary to set the tact time shorter than the cycle time. However, since the tact time cannot be set shorter than the cycle time, the target production quantity is decreased and the maintenance work is incorporated into the plan. Step S74 is the same as step S72 in that the tact time is shortened, but different in that the target production quantity is decreased. Also, step S74 is the same as step S70 in that the target production quantity is decreased, but different in that the tact time is shortened. By changing the production plan 81 in step S74, as in step S70, although the target production quantity decreases, it is possible to take early measures to compensate for the decreased production quantity. Also, by shortening the tact time, it is possible to make the decrease in the target production quantity smaller than when the tact time is not shortened. After the execution of step S74, the control unit 21 ends this processing routine.

[0030] According to the first embodiment described above, the production plan establishment system 20 includes a determination unit 31, an acquisition unit 32, a calculation unit 33, and a modification unit 34. The determination unit 31 determines whether or not the predicted value of the detection value at the reference time t1 obtained by subtracting the lead time from the prediction time t2 exceeds the reference value by comparing the variable V indicating the detection value with the absolute value of the variable B indicating the reference value (step S16). When it is determined that the variable V is greater than the absolute value of the variable B, that is, when it is determined that the detection value exceeds the reference value, the acquisition unit 32 acquires the maintenance work time and substitutes it into the variable M (step S38). The calculation unit 33 calculates a variable t indicating the shortening time of the tact time for generating the maintenance work time within the lead time by executing a shortening time calculation process (step S40) using the variable M indicating the maintenance work time. The modification unit 34 changes the current tact time to a production plan 81 using the shortened tact time obtained by subtracting the shortening time from the current tact time (step S72). Thereby, the maintenance work can be predicted in advance, and when the maintenance work is necessary, the maintenance work can be performed without changing the target production quantity by shortening the tact time.

[0031] Further, when the shortened tact time obtained by decreasing the current tact time by the variable t indicating the shortening time is shorter than the cycle time, the modification unit 34 changes to a production plan 81 including a decrease in the target production quantity (step S74). Thereby, when the shortened tact time is shorter than the cycle time, it is possible to change to a production plan 81 including a decrease in the target production quantity.

[0032] Further, the determination unit 31 determines whether or not the variable V indicating the detection value is greater than the variable B indicating the reference value using the reference value set in the prediction data 83 (step S16). Thereby, the determination unit 31 can determine whether or not the detection value exceeds the reference value using the prediction data 83.

[0033] B. Second Embodiment: FIG. 8 is a flowchart of the production plan creation process according to the second embodiment. In the production plan creation process according to the first embodiment, it is performed for one facility F, but in this embodiment, it is performed for a plurality of facilities F. The same processing steps as those in the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted as appropriate.

[0034] When the production plan creation system 20 receives an execution of the production plan creation process, it executes the production plan creation process. The production plan creation process is performed, for example, every day.

[0035] The determination unit 31 substitutes the initial value "1" into the variable m, and sets the facility Fm, which is the facility F with the facility ID "m", as the target in the subsequent steps S13 to S17 (step S10). The determination unit 31 refers to the prediction data 83 and substitutes the reference value of the facility Fm into the variable B (step S13). The determination unit 31 substitutes the latest detected value of the facility data 82 into the variable V (step S15).

[0036] The determination unit 31 determines whether the variable V exceeds the reference value (step S17). As described above, whether the value indicating the performance increases or decreases as the performance deteriorates depends on the facility F. In the case of the facility F where the value indicating the performance increases as the performance deteriorates, such as the facility F1, in step S17, similar to step S16 according to the first embodiment, it is determined whether the variable V is greater than the absolute value of the variable B. And when the variable V is determined to be greater than the absolute value of the variable B, it is determined that the detected value exceeds the reference value. On the other hand, when the variable V is determined not to be greater than the absolute value of the variable B, it is determined that the detected value does not exceed the reference value. In the case of the facility F where the value indicating the performance decreases as the performance deteriorates, in step S18, it is determined whether the variable V is smaller than the absolute value of the variable B. And when the variable V is determined to be smaller than the absolute value of the variable B, it is determined that the detected value exceeds the reference value. On the other hand, when the variable V is determined not to be smaller than the absolute value of the variable B, it is determined that the detected value does not exceed the reference value.

[0037] When it is determined that the detected value exceeds the reference value (step S17: YES), the determination unit 31 stores the value of the target equipment ID, that is, the variable m, in the memory 23 (step S20). On the other hand, when it is determined that the detected value does not exceed the reference value (step S17: NO), the determination unit 31 does not store the target equipment ID in the memory 23 and proceeds to step S22 with respect to the variable V.

[0038] The determination unit 31 increments the variable m (step S22), and the variable m determines whether it is greater than the variable s indicating the total number of equipment F (step S24). When it is determined that the variable m is not greater than the variable s, that is, the variable m is less than or equal to the variable s (step S24: NO), the determination unit 31 proceeds to step S10 to determine the next equipment F. When it is determined that the variable m is greater than the variable s (step S24: YES), since the determination for all equipment F has been completed, the control unit 21 proceeds to step S30.

[0039] The change unit 34 substitutes the current tact time into the variable T and substitutes the cycle time into the variable C (step S30). The change unit 34 determines whether the variable T is greater than the variable C (step S32). When it is determined that the variable T is not greater than the variable C (step S32: NO), the change unit 34 changes the production plan 81 in the same manner as in the first embodiment (step S70). After the execution of step S70, the control unit 21 ends this processing routine.

[0040] When the change unit 34 determines that the variable T is greater than the variable C (step S32: YES), the acquisition unit 32 refers to the prediction data 83, extracts the lead time associated with the stored equipment ID, and obtains the shortest lead time (step S34). The change unit 34 refers to the prediction data 83, extracts the maintenance work time associated with the stored equipment ID, and obtains the longest maintenance work time, that is, the longest maintenance work time (step S36).

[0041] FIG. 9 is a diagram for explaining prediction data 83. The prediction data 83 is a database in which an equipment ID, a lead time, and a maintenance work time are associated in a set. The prediction data 83 is created using the results of past maintenance work. For example, for equipment F1, when the detected value exceeds the reference value, it is predicted that the detected value will exceed the limit value after 140 hours. The maintenance work for equipment F1 is 0.5 hours.

[0042] The acquisition unit 32 substitutes the acquired longest maintenance work time into the variable M, and substitutes the acquired shortest lead time into the variable P (step S39). The calculation unit 33 performs a shortening time calculation process (step S40). In the shortening time calculation process according to the present embodiment, in step S54 (FIG. 6), the total time b is calculated using the target production number at the shortest lead time acquired in step S36 (FIG. 8). Also, in step S56 (FIG. 6), it is determined using the longest maintenance work time acquired in step S34 (FIG. 8). As a result, when maintenance work is required for a plurality of equipment F, the maintenance work can be performed on the plurality of equipment F at the same time. For example, when it is determined that the equipment F1, equipment F3, and equipment F5 shown in FIG. 9 have reached the reference time t1, by generating a maintenance work time of 1.5 hours, which is the longest maintenance work time, the maintenance work for three pieces of equipment F can be performed with a single stop of the production line 10. The frequency of stopping the production line 10 can be reduced compared to performing the maintenance work in accordance with the end of the lead time for each of the plurality of equipment F.

[0043] The changing unit 34 determines whether the total time b of the returned values is greater than the variable M indicating the maintenance work time (step S42). When it is determined that the total time b is greater than the variable M (step S42: YES), the changing unit 34 changes to the production plan 81 in the same manner as in the first embodiment (step S72). Specifically, the changing unit 34 sets the stop time of the production line 10 for performing the maintenance work of the plurality of facilities F within the longest maintenance work time. When it is determined that the total time b is not greater than the variable M (step S42: NO), the changing unit 34 changes to the production plan 81 in the same manner as in the first embodiment (step S74). After executing step S72 and after executing step S74, the control unit 21 ends this processing routine.

[0044] According to the second embodiment described above, in step S40, the calculation unit 33 calculates the shortening time using the margin time of the facility F with the shortest margin time and the maintenance work time of the facility F with the longest maintenance work time among the plurality of facilities F for which it is determined that maintenance work is necessary. Thereby, since the maintenance work for the plurality of facilities F can be performed in the same period, the maintenance work can be efficiently carried out.

[0045] C. Other Embodiments: (C1) The control unit 21 may further include an update unit as a functional unit. When the shortened tact time is shorter than the cycle time, the update unit updates the prediction data 83 so that the reference value is moved away from the limit value so that the margin time becomes longer. Specifically, after executing step S74 of the production plan creation process according to the first embodiment, a processing step (update step) may be inserted in which the update unit updates the prediction data 83 so that the reference value is moved away from the limit value so that the margin time becomes longer. The shortened tact time being shorter than the cycle time means a case where the maintenance work time cannot be generated even if the tact time is shortened until it becomes the same as the cycle time. In this case, by setting the reference value so that the margin time becomes longer, in the next production plan creation process, the adjustment to shorten the tact time can be made earlier, so the possibility of performing the maintenance work without changing the target production quantity can be increased.

[0046] (C2) The control unit 21 may further include a setting unit as a functional unit. The setting unit sets a longer buffer time as the maintenance time of the facility F is longer in the prediction data 83. Thereby, even when the maintenance time is long, by setting a longer buffer time, the maintenance time can be generated by shortening the tact time.

[0047] (C3) As described above, the detected value is a detected value indicating a friction coefficient, a detected value indicating a torque value, or the like. The timing when the maintenance work is to be performed can also be predicted using the integrated time of the operating time and the integrated value of the production quantity from the previous maintenance work. Therefore, as the detected value, the integrated time of the operating time of the facility F since the previous maintenance work and the integrated value of the production quantity may be used. That is, the detected value may be the integrated time of the operating time detected by the timer or the integrated value of the production quantity.

[0048] (C4) In step S70 of the production plan creation process according to the first embodiment, it is changed to the production plan 81 in which the maintenance work is performed at the end of the buffer time. The timing when the maintenance work is to be performed is not limited to the end of the buffer time. For example, when the end of the buffer time is in the middle of the operating time of one day, it may be changed to the production plan 81 in which the maintenance work is performed at the end of the operating time of the previous day. Thereby, within the operating time of one day, an interruption for performing the maintenance work can be avoided.

[0049] (C5) In the first embodiment, when it is determined that the total time b is not greater than the variable M (step S42: NO), the change unit 34 decreases the target production quantity, changes it to a value obtained by subtracting the variable t from the current tact time, and changes it to the production plan 81 incorporating the maintenance work plan (step S74). Separately from this, the change unit 34 may change the production plan 81 to decrease the target production quantity without shortening the tact time and incorporating the maintenance work plan. Thereby, even when a sudden stop of the production line 10 occurs, it is possible to change to a production plan 81 with a margin to avoid changing the target production quantity.

[0050] (C6) In the first embodiment described above, the equipment data 82 and the prediction data 83 are stored in the memory 23 of the production plan establishment system 20. The device in which the equipment data 82 and the prediction data 83 are stored is not limited to the production plan establishment system 20. For example, it may be stored in a server that can communicate with the production plan establishment system 20. Further, when each of the equipment F detects a value exceeding the reference value, a signal may be transmitted to the production plan establishment system 20, and when the production plan establishment system 20 receives the signal, it may determine that the detected value exceeds the reference value.

[0051] The present disclosure is not limited to the above-described embodiments, and can be realized in various configurations without departing from the gist thereof. For example, the technical features of the embodiments corresponding to the technical features in each of the forms described in the summary of the invention can be appropriately replaced or combined in order to solve some or all of the above-described problems or to achieve some or all of the above-described effects. Further, if the technical feature is not described as essential in this specification, it can be appropriately deleted.

Description of Reference Numerals

[0052] 10... production line, 20... production plan establishment system, 21... control unit, 22... CPU, 23... memory, 24... display, 25... keyboard, 31... determination unit, 32... acquisition unit, 33... calculation unit, 34... modification unit, 50... communication unit, 51... drive unit, 52... roller, 53... detection sensor, 81... production plan, 82... equipment data, 83... prediction data, F, F1 to F5, Fs... equipment, W... product

Claims

1. A production plan establishment system, The production plan establishment system formulates a production plan for a production line, including a takt time calculated by dividing the operating time of the production line by the target production quantity, A determination unit that determines whether a detection value indicating the performance of equipment used in the production line exceeds a reference value that is a predicted value of the detection value at a reference time obtained by subtracting a lead time from a predicted time at which maintenance work for the equipment is predicted, When the determination unit determines that the reference value has been exceeded, an acquisition unit that acquires the maintenance work time required for the maintenance work, A calculation unit that calculates a reduction time of the takt time for generating the maintenance work time within the lead time using the lead time and the maintenance work time, and when the reduced takt time obtained by subtracting the reduction time from the takt time is less than or equal to the cycle time, calculates the time obtained by subtracting the cycle time from the takt time as the reduction time, A change unit that changes the production plan, and is provided with, The change unit, When the reduced takt time is longer than the cycle time, changes the previous production plan to the production plan using the reduced takt time, When the reduced takt time is less than or equal to the cycle time, changes the previous production plan to the production plan using the reduced takt time, which includes a decrease in the target production quantity, a production plan establishment system.

2. The production plan establishment system according to claim 1, The production line includes a plurality of the equipment, The lead time and the maintenance work time are determined in advance for each of the plurality of equipment, When the determination unit determines that the detection value exceeds the reference value for the plurality of facilities, the calculation unit uses the margin time of the facility with the shortest margin time among the plurality of facilities for which it is determined that the detection value exceeds the reference value, and the longest maintenance work time, which is the maintenance work time of the facility with the longest maintenance work time, to calculate the shortening time. The change unit sets the stop time of the production line for performing the maintenance work of the plurality of facilities within the longest maintenance work time, a production plan establishment system.

3. The production plan establishment system according to claim 1 or 2, wherein The determination unit is communicable with a storage unit storing prediction data in which a limit value, which is the detection value at the prediction time, the reference value, and the facility are associated, The determination unit determines using the reference value of the prediction data, a production plan establishment system.

4. The production plan establishment system according to claim 3, further comprising a setting unit that sets the margin time longer as the maintenance work time is longer, a production plan establishment system.

5. A production plan establishment method, wherein the production plan establishment method is a production plan of a production line, and includes a planning step of establishing a production plan including a tact time calculated by dividing the operating time of the production line by the target production quantity, a determination step of determining whether or not a detection value indicating the performance of a facility used in the production line exceeds a reference value that is a predicted value of the detection value at a reference time obtained by subtracting a margin time from a prediction time at which maintenance work of the facility is predicted, an acquisition step of acquiring a maintenance work time required for the maintenance work when it is determined in the determination step that the reference value is exceeded, A calculation step of calculating a reduction time of the tact time for generating the maintenance work time within the grace period by using the grace period and the maintenance work time, wherein when the reduced tact time obtained by subtracting the reduction time from the tact time is equal to or less than the cycle time, the calculation step calculates the time obtained by subtracting the cycle time from the tact time as the reduction time; A change step of changing the previous production plan to the production plan using the reduced tact time when the reduced tact time is longer than the cycle time, and changing the previous production plan to the production plan using the reduced tact time, which includes a decrease in the target production quantity, when the reduced tact time is equal to or less than the cycle time. A production plan formulation method comprising:

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