JPH07192051A - Manufacturing schedule preparation device - Google Patents

Abstract

PURPOSE:To provide a manufacturing schedule preparation device capable of extracting an important process which is the obstruction of smooth physical distribution and production at the present point of time and deciding an optimum processing order in the process in practical time. CONSTITUTION:This device is constituted of an equipment storage part 1 for storing product information, process information and equipment information in a production line, a tracking data description part 2 for storing the start information of a product, an important process extraction part 3 for extracting the important process of the production line by a prescribed rule by using the respective pieces of information, a simulation part 4 for obtaining the estimated arrival time of the product at the important process by simulating production time until the important process in the production line and a processing order deciding part 5 for deciding the processing order of the product by performing an arithmetic operation for obtaining productivity in the production line by a prescribed arithmetic method by using the estimated arrival time of the product, etc. By the constitution, the important process is extracted and the optimum processing order in the process is decided in the practical time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing plan creating apparatus, and more particularly to a manufacturing plan creating apparatus for automatically creating a job input sequence for improving production efficiency in a production plan for a wide variety of products in a job shop. It is a thing.

[0002]

2. Description of the Related Art In the conventional production schedule technology, a skilled worker creates it by observing the current work-in-process status of the product and the operating status of the apparatus. However, when relying on skilled workers to create a production schedule, manufacturing efficiency may fluctuate depending on the degree of skill and individuality, or all conditions may not be taken into consideration. Also, it took a lot of time and effort to create the schedule. In addition, such a schedule is not always a schedule with good production efficiency because unexpected load is applied to a specific device, semi-finished products are accumulated, or the device remains empty. There wasn't. For this reason, a manufacturing plan preparation device has been proposed as a device for automatically preparing a production plan (Japanese Patent Laid-Open No. 130780/1990). In this conventional manufacturing plan creation apparatus, a lot arrival procedure and an introduction strategy are determined from product information, process information and work-in-process information according to a predetermined rule. Next, the equipment is assigned to the job according to the equipment allocation rule, and the dispatching for allocating the accumulated job is determined according to the dispatching rule. A simulation is performed based on these information, and the results are evaluated by the evaluation means, and the number of setup changes, delivery rate, and
The average number of work in progress is weighted at 7: 2: 1 for evaluation.

[0003]

In the above-described conventional manufacturing plan creating apparatus, a target process (a neck process having the lowest productivity) to be targeted in determining the order of starting jobs.
Is fixed. However, when a job goes through complicated processing steps, the attention step may change from moment to moment depending on the physical distribution. For this reason, the above conventional device cannot be expected to provide sufficient support. In addition, by selecting a combination of multiple algorithms prepared in advance according to the situation, the introduction strategy, the starting order, equipment allocation, and dispatching are determined respectively, so that optimum production efficiency is always obtained. Not really. The present invention has been made in view of the above circumstances, and a first object thereof is to extract a process that is an obstacle to smooth distribution and production at the present time and determine an optimum processing sequence in the process. To do. Further, the second purpose is to predict the production status when the production is performed using the processing order thus determined.

[0004]

In order to achieve the first object, the present invention stores equipment description means for storing product information, process information and equipment information in a production line, and product in-process information. The tracking data description means, the product information, the process information and the equipment information stored by the equipment description means, and the product in-process information stored by the tracking data description means are used to determine the production line of the production line according to a predetermined rule. A simulation for obtaining an expected arrival time of a product to the priority process by performing a simulation of the priority process extraction means for extracting the priority process and the production time up to the priority process extracted by the priority process extraction means in the production line. Means and a predetermined calculation using the expected arrival time of the product obtained by the simulation means By performing an operation for obtaining the productivity in the production line by law, and is configured as a manufacturing planning apparatus and a processing order determining means for determining the processing order of the product. Further, in order to achieve the second object, the simulation means performs simulation again using the processing order of the products determined by the processing order determination means to predict the in-process state of the products in all steps. It is configured as a manufacturing plan creation device. The product information and process information include the type of equipment used for processing the product to be produced and the standard time required for those equipment. In addition, the equipment information includes the types and the number of devices existing in the equipment, the processing contents in those equipments, and the quantity of products that can be processed at one time.

[0005]

According to the present invention, the product information, the process information and the facility information in the production line are stored by the facility description means, and the in-process information of the product is stored by the tracking data description means. According to a predetermined rule, the priority process of the production line is the priority process using the product information, the process information and the facility information stored by the facility description means and the product in-process information stored by the tracking data description means. It is extracted by the extraction means. By simulating the production time up to the priority process extracted by the priority process extraction means in the production line, the expected arrival time of the product to the priority process is obtained by the simulation means. The processing order determining means determines the processing order of the products by performing the calculation for obtaining the productivity in the production line according to a predetermined calculation method using the expected arrival time of the product obtained by the simulation means. In this way, prioritized processes that are obstacles to smooth distribution and production at this time are extracted,
The optimum processing order in the process can be determined in a practical time. Further, the simulation means performs simulation again using the processing order of the products determined by the processing order determination means,
When the in-process status of products in all processes is predicted, it is possible to study the operating conditions, the layout of the factory, the number of devices, etc. from the predicted in-process status, so that the equipment can be used widely. You can

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the accompanying drawings for the understanding of the present invention. The following embodiments are examples of embodying the present invention and are not intended to limit the technical scope of the present invention. Here, FIG. 1 shows a manufacturing plan creating apparatus 0 according to an embodiment of the present invention.
2 is a schematic flow chart showing the operation of the manufacturing plan creation device 0, FIG. 3 is a diagram showing an example of a priority process extraction rule, and FIG. 4 is a diagram showing a result of priority process extraction. 5 is a diagram showing the comparison of the processing order between the case where the processing order determining unit is used and the case where the processing order determining unit is not used, and FIG. 6 is the simulation result of the case of optimization and the case of not optimizing. FIG. 7 is a diagram showing a comparison of in-process number distributions in each process, FIG. 7 is a diagram showing an example of modeling a production line, FIG. 8 is a diagram showing an example of product information, and FIG. 9 is a diagram showing an example of device information used. 10 is a table showing an example of work-in-progress information, FIG. 11 is a view showing the result of a work-in-process schedule by the FIFO, FIG. 12 is a diagram showing the result of work-in-process scheduling by the device 0, and FIG. 13 is a work-in-process. Information and process priorities (used by all devices FIG. 14 is a diagram showing work-in-progress information and process priorities (when the device C1 cannot be used), and FIG. 15 is a result of work-in-process scheduling by the FIFO (device C1 is time 11: FIG. 16 is a diagram showing a case in which the device 0 cannot be used), and FIG. 16 is a diagram showing a result of a work-in-process schedule by the device 0 (when the device C1 is not available from 11:30).

As shown in FIG. 1, a manufacturing plan creating apparatus 0 according to the present embodiment includes an equipment description section 1 (corresponding to equipment description means) for storing product information, process information and equipment information in a production line, and a product description section. A tracking data description section 2 (corresponding to tracking data description means) for storing work-in-progress information, product information, process information and equipment information stored by the equipment description section 1, and a product stored by the tracking data description section 2 Up to the priority process extraction unit 3 (corresponding to the priority process extraction means) that extracts the priority process of the production line by a predetermined rule using the in-process information and the priority process extracted by the priority process extraction unit 3 of the production line. The simulation unit 4 which obtains the expected arrival time of the product in the priority process by simulating the production time
(Corresponding to the simulation means) and the expected arrival time of the product obtained by the simulation unit 4 to perform a calculation for obtaining the productivity in the production line by a predetermined calculation method, thereby determining the processing order of the product. An order determining unit 5 (corresponding to a processing order determining unit). Further, the simulation unit 4 may predict the in-process state of products in all processes by performing simulation again using the processing order of the products determined by the processing order determination unit 5. Less than,
The operation of the apparatus 0 will be briefly described in the order of steps S1, S2, ... With reference to FIG. Product information, process information, and facility information regarding the target production line are registered in the facility description unit 1 in advance. Specifically, as the product information and process information, the type of equipment used by the product to be produced and the standard required time at each equipment are described. As the equipment information, the type and number of devices existing in the equipment, the processing content of each equipment, the quantity that can be processed at one time, and the like are described. The in-process information of the product and the information about the operating state of the equipment are updated every time the apparatus 0 is started, and the latest data is transferred from a higher-level computer (not shown) and updated. Further, the priority process extraction rule corresponds to the above-mentioned predetermined rule, which is a rule in which production management know-how is organized and is registered in advance in the priority process extraction unit 3.

Under these conditions, first, the type and number of semi-finished products in process of each process at the start time of the schedule, the in-process state (processing, waiting state), past production history, for example, yesterday's Tracking data, which is in-process information such as the number of processes, is transferred from the host computer (S
1), stored in the tracking data description unit 2 (S
2). Next, these data are input to the priority process extraction unit 3, and the priority process is determined for each work category according to the priority process extraction rule (S3). That is, first, the priority process extraction unit 3
Tracking data is input from the tracking data description section 2 to determine the priority of each process in accordance with the priority process extraction rule as shown in FIG. 3, for example. This priority process extraction rule, for example, does not cause material interruption in the next process, considers material supply to maximize productivity for equipment with inferior production capacity, and gives priority to places with large in-process inventory. This is achieved by processing and leveling the in-process amount in all processes. The result of determining the priority process is shown in FIG. In the figure, the number of products in process with process number n-1 is the largest and the priority is the highest. Next, check the load status of each device. Since one process does not necessarily use one device, the corresponding process and each in-process amount in each process are listed, and the device operation time is maximized while referring to the priority of the process determined earlier. The processing amount for each process is determined so that The simulation unit 4 uses the tracking data at the current time as an initial value to perform simulation up to the priority process previously determined by the priority process extraction unit 3 for a designated time such as after 8 hours or 16 hours. The in-process state after this designated time is predicted (S4). In this case, the product (job) that has arrived at the previously determined priority process is stopped as a work-in-progress of the priority process without proceeding to the simulation beyond that process.
By stopping the simulation in the priority process, information for optimizing the processing sequence in the priority process is collected.

The processing order determination unit 5 determines the optimum processing order based on the staying state of the product in the priority process, the estimated arrival time, the delivery margin, etc. (S5). Here, the optimum processing sequence is determined within a practical time from the staying state of the semi-finished products in the priority process obtained by the previous simulation and the estimated arrival time of each job. At this time, as the predetermined calculation method, an evaluation function f as defined below is used, and the jobs are replaced so as to minimize the evaluation function f. f = α (Σ express job waiting time) + β (Σ delivery delay)
+ Γ (processing end time) + η (Σ waiting time for general jobs)
→ MIN However, each coefficient represented by α, β, γ, η is a value obtained by experience. FIG. 5 shows the result of comparison between the case where the job processing order is optimized and the case where the job processing order is not optimized (processed in the order of job arrival). As can be seen from the figure, in the optimized processing order, the devices MC1, MC2,
The vacant time of ... decreases and the operation rate is high. By the way, the setup change time that occurs due to the difference in the types of products to be processed should be minimized at the same time, but this condition has already been taken into consideration rather than minimizing the processing end time. In addition, the express job is a job with a severe penalty especially for late delivery. Since this cannot be reflected sufficiently by minimizing the waiting time for general jobs, it is provided as a separate item. The processing order of the jobs is determined so as to minimize the evaluation function f determined in this way, but this is the optimal solution under the current circumstances, and it seems that the processing order determined by the operator simply cannot be thought of. A good order may be chosen. Further, it is difficult to add many conditions at the same time in a predetermined processing sequence according to a certain processing sequence. Step S
The processing order determined in 5 can be used for production as it is, but here, in order to confirm the processing order and clarify the work prospect, a simulation is performed. The simulation unit 4 uses the processing order determined as described above.
The simulation was performed again by
In-process states such as after 10, 16 and 24 hours are predicted (S6 to S8).

Now, using the tracking data at the current time as an initial value, a simulation is performed again using the determined processing order, and the in-process state 8 hours after the current time is predicted. The expected distribution of the in-process state thus obtained is as shown in FIG. 6, which is used for the evaluation of the processing sequence, and also serves as an instruction to the production site together with the production plan. In the figure, the vertical axis shows the number of products in process, and the horizontal axis shows the process number, and the effect of optimization is clearly recognized here. Furthermore, when looking at this result and changing the processing order of a part under special conditions or non-stationary conditions not included in the evaluation function f, change this,
The simulation can be performed again by the simulation unit 4 to confirm the effect. Alternatively, when the item of the clear evaluation function f is not decided yet,
By repeating the simulation, it is possible to select appropriate evaluation items. Subsequently, the operation and the like of the device 0 are evaluated. Specifically, assuming a model of the production line as shown in FIG. 7, when the product (type 1, 2) of the type as shown in FIG. 8 is processed in this model, the priority process extraction unit 3, How the simulation unit 4 and the processing order determination unit 5 work will also be described. Here, it is assumed that the apparatus information usable in each process is as shown in FIG. 9, and the in-process information used as the initial state is given in FIG.

FIG. 11 shows a general FIFO (First)
In First Out). FIG. 12 shows the result of the schedule by the device 0. Both simulators are used to create the schedule. The priority process extraction unit 3 of the present apparatus 0 determines the priority order as shown in FIG. 13 from the in-process information. Here, since the first process and the fifth process are (the number of work in progress is large) and (the number of work in progress of the next process is small) are assigned according to the priority process extraction rule, a high priority is given. In the above FIGS. 11 and 12,
The work in process of the first process is shaded, and the work in process of the fifth process is shaded. The processing order determination unit 5 obtains the arrival time of the work in process at each work center queue from the result of the provisional scheduling by the FIFO, and improves based on this. For example, the processes using the work center B are the second and fifth processes for both products 1 and 2. Since the priority of the fifth process is high, in the FIFO shown in FIG. 11, the job 1008 is executed by the device B2 of the work center B at time 12:
While the process was started from 10, in this device 0,
As shown in FIG. 12, the job 1004 is processed by the device B2, and the job 1008 is processed by the device B3 of the same work center B. As a result, time 1
Processing can be started from 1:40. Since the processing in the fifth step is completed early for the job 1008, the processing start time in the seventh step, which is the next step, is also shortened. Further, the processing order determination unit 5 also minimizes the idle time of the device, and therefore reduces the idle time of the devices A1 and A2 of the work center A.
The processing of 012 and 1011 precedes the job 1010. The total of these improvement times is 100 minutes.
Further, at work center B, jobs 1008 and 100
Since 9 is the same product type and the same process, the number of setup changes could be reduced by one. With these processes, the processing start time of the job 1010 in the third and fourth steps and the job 1014 in the second step is delayed by a total of 80 minutes as compared with the FIFO. If these plus and minus are summed, this device 0
In the case of using, the work-in-process residence time was shortened by 20 minutes and the number of setup changes was reduced by one compared with a general FIFO.

Further, as an example in which the order of priority of processes must be changed according to the situation, the device C1 of the work center C is used.
Consider a case where the machine is out of order or has stopped due to maintenance work. In the next step, the step of using the device C1,
The second process of the products 1 and 2 and the fifth process of the product 2 have lower priorities, as shown in FIG. Here, the priority of the fifth process is higher than that of the fifth product type 1.
Since the work center D is used in the next process, the device C
This is because it is not affected by the failure of 1. FI in this case
The schedule results using FO and this device 0 are shown in FIGS. Therefore, by using the present device 0, the staying time of the work in process is shortened by 100 minutes in total, and the time to enter the queue to the unusable device C1 due to the stop is delayed by 105 minutes as compared with the case of using the FIFO. I was able to. As described above, by appropriately determining the process to be prioritized according to the operating status of the apparatus, the work in progress, and the like, and using the processing order determination unit 5, it is possible to create a schedule better than the FIFO. Summarizing the above, the following can be said. According to this apparatus 0, it is possible to extract a priority process that is an obstacle to smooth physical distribution and production at the present time, and determine the optimum processing sequence in that process in a practical time. Further, when the simulation unit 4 predicts the in-process state of the products in all the processes by performing the simulation again using the processing order of the products determined by the processing order determination unit 5, it is predicted. From the work in progress, it is possible to examine the operating conditions, the layout of the factory, the number of devices, etc., so that the devices can be widely used.

In the above embodiment, an algorithm that imposes certain constraint conditions is used as the priority process extraction rule which is a predetermined rule, but in actual use,
There is no problem in using other types of rules such as neural networks. In the above embodiment, as a predetermined calculation method, the jobs are replaced so as to minimize the evaluation function f. However, in actual use, the contents of the evaluation function are replaced to take the maximum value. Jobs may be exchanged. Further, when it is applied to a large-scale production line, the result can be obtained in a practical time by using an optimization method such as a simulated annealing method. In the above embodiment, the priority process extraction unit 3, the simulation unit 4, and the processing order determination unit 5 are included.
Is embodied by each process constructed as software in a computer, for example, but in actual use, all or part of these may be configured as a hardware.

[0014]

Since the manufacturing plan creating apparatus according to the present invention is configured as described above, the priority process which is an obstacle to smooth physical distribution and production at the present moment is extracted, and the optimum process in that process is extracted. The processing order can be determined in a practical time. Further, when the simulation means predicts the in-process state of the product in all the processes by performing the simulation again using the processing order of the products determined by the processing order determination means, it is predicted. Since it is possible to study the operating conditions, the layout of the factory, the number of devices, etc. from the state of work in progress, a wide range of equipment can be used.

[Brief description of drawings]

FIG. 1 is a manufacturing plan creating apparatus 0 according to an embodiment of the present invention.
FIG.

FIG. 2 is a schematic flowchart showing the operation of the manufacturing plan creation device 0.

FIG. 3 is a diagram showing an example of a priority process extraction rule.

FIG. 4 is a diagram showing a result of priority process extraction.

FIG. 5 is a diagram showing a comparison of processing order between the case where the processing order determining unit is used and the case where the processing order determining unit is not used.

FIG. 6 is a diagram showing a comparison of simulation results and in-process number distributions in each process, with and without optimization.

FIG. 7 is a diagram showing an example of modeling a production line.

FIG. 8 is a chart showing an example of product information.

FIG. 9 is a chart showing an example of used device information.

FIG. 10 is a chart showing an example of work-in-progress information.

FIG. 11 is a diagram showing a result of a work-in-process schedule by FIFO.

FIG. 12 is a diagram showing a result of a work-in-process schedule by the present apparatus 0.

FIG. 13 is a diagram showing in-process information and process priorities (when all devices can be used).

FIG. 14 is a diagram showing work-in-process information and process priorities (when the device C1 cannot be used).

FIG. 15 is a diagram showing a result of a work-in-process schedule by the FIFO (when the device C1 cannot be used from 11:30).

FIG. 16 is a diagram showing a result of a work-in-process schedule by the present device 0 (when the device C1 is unavailable from time 11:30).

[Explanation of symbols]

0 ... Manufacturing plan creation device 1 ... Equipment description section (corresponding to equipment description means) 2 ... Tracking data description section (corresponding to tracking data description means) 3 ... Focused process extraction section (corresponding to priority process extraction means) 4 ... Simulation section (Corresponding to simulation means) 5 ... Processing order determining unit (corresponding to processing order determining means)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takashi Fukushima, inventor 1-5-5 Takatsukadai, Nishi-ku, Kobe-shi, Hyogo Prefecture Kobe Steel Research Institute, Kobe Steel Co., Ltd. (72) Masami Konishi Nishi-ku, Kobe-shi, Hyogo Takatsukadai 1-5-5 Kobe Steel Co., Ltd. Kobe Research Institute

Claims (2)

[Claims] 1. A facility description means for storing product information, process information and facility information on a production line, a tracking data description means for storing product in-process information, and product information and processes stored by the facility description means. Priority process extracting means for extracting priority processes of the production line according to a predetermined rule using the information and facility information and the in-process information of the product stored by the tracking data description means, and the priority processes in the production line By using the simulation means for obtaining the expected arrival time of the product to the priority process by simulating the production time until the priority process extracted by the extraction means, and the expected arrival time of the product obtained by the simulation means. Perform the calculation to obtain the productivity in the above production line by the predetermined calculation method. And a processing order determining means for determining the processing order of the product. 2. The manufacturing plan according to claim 1, wherein the simulation means predicts a work-in-progress state of products in all processes by performing simulation again using the processing order of the products determined by the processing order determination means. Creation device.