A certain aspect of embodiments described herein relates to an information processing device, a setup operation modification method, and a non-transitory computer-readable recording medium.
When a plurality of lines is used to process products, it is desirable to create a plan so that the processing, completion time is reduced as disclosed in Japanese Laid-Open Patent Publication No, 2006-287075. In the case of high-mix low-volume production, setting change referred to as setup is performed each time the type of the product to be manufactured is changed as disclosed in Japanese Laid-Open Patent Publication Nos. 2017-21764 and 2015-65382.
It is desirable to reduce the processing completion time by devising the order of setup operations. However, when the setup operations are performed in the order of lines where the processing operation is completed, the time to completion of the processing may become long.
According to one aspect of embodiments, there is provided an information processing device including: a memory; and a processor coupled to the memory and configured to: rearrange setup operations with respect to an initial input order according to which products are to be input to a processing line including a plurality of lines to which a product that requires a setup operation and a processing operation is to be input, setup operations being not executed with the setup operations overlapped with each other in the plurality of lines, determine a processing completion time of the processing line based on the rearranged setup operations, and determine, as planning data, an order of setup operations that achieves a processing completion time less than a processing completion time of the initial input order among the processing completion time calculated.
The object and advantages of the invention will be realized and attained b means of the elements and combinations particularly pointed out in the claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed.
When high-mix low-volume production is performed using a surface mounting line or a processing equipment that performs various types of processing, the type of product changes many times in the course of a day. Thus, each time the type of product is changed, the setting of the surface mounting line or the setting of the processing equipment is changed. Such setting changes are referred to as “setup”. An operation for setting change is referred to as a “setup operation”. The time required for the setup operation is referred to as a “setup operation time”. The “setup” is also referred to as “changeover”.
While the setup operation is performed, processing by the surface mounting line or the processing equipment is stopped. The setup operation time diners depending on the product. Therefore, the processing completion time, which is the time required to complete the processing of all products, can be reduced by devising the execution order of the setup operations. However, when the execution order of setup operations at a certain point in time is devised, it will affect the progress of subsequent processing. Thus, to determine the optimal execution order of setup operations, it is desirable to solve a complex optimization problem taking into account the influence on later events.
Here, a case where products with different processing operation times and different setup operation times flow through a line 1 and a line 2 of a processing line will be considered. For example, as illustrated in
However, when one worker is in charge of both the line 1 and the line 2, the worker cannot perform the setup operations in the two lines at once. Therefore, when the times for the setup operations in the two lines overlap, the worker need to perform the setup operations in the two lines in sequence. Normally, as illustrated in
For example, as illustrated in
Therefore, it may be considered to present the order of setup operations in real tune so that the processing completion time becomes shortest taking into consideration the deviation between the manufacturing plan and die actual result when the setup operations overlap. However, when the rearrangement of the input order of products is taken into consideration, more computation time is required. In addition, this method only focuses on improving the efficiency of the changeover operation, and the influence of the calculation results on other processes needs to be considered separately.
Thus, to take into consideration the propagation effect on other processes, it may be considered to create a work plan by planning a processing plan using a line simulator. However, this method is a system for planning an input plan, the optimization is not performed on the work plan, such as a proposal for avoiding the overlap of setup operations, that is not expressed in the input plan.
In embodiments described hereinafter, an information processing device, a setup operation modification method, and a setup operation modification program that can reduce the processing completion time will be described as an example.
The CPU (central processing unit) 101 is a central processing unit. The CPU 101 includes one or more cores. The RAM (random access memory) 102 is a volatile memory that temporarily stores a program executed by the CPU 10.1 and data processed by the CPU 101. The storage device 103 is a nonvolatile storage device. Used as the storage device 103 is, for example, a ROM (read only memory), a solid state drive (SSD) such as a flash memory, or a hard disk driven by a hard disk drive. The storage device 103 stores a setup operation modification program. The display device 104 is a liquid crystal display, an electro luminescence panel, or the like, and displays results of the setup operation modification process. In the present embodiment, the optimization engine 10, the product information storage unit 20, the input order storage unit 30, the layout storage unit 40, the worker information storage unit 50, and the optimal order storage unit 60 are implemented by the execution of the program, but hardware such as a dedicated circuit may be used.
First, a description will be given of a method of expressing the setup operation in the line simulator 11. For example, the basic operation of the line simulator 11 is based on Asymmetric Simple Exclusion Process (ASEP). ASEP is based on a simple idea that a product can proceed only when the front is empty. However, in a production site, products are moved according to the rule specific to the production site. Therefore, how the product is to be moved next is determined in an instruction block that defines how the product is moved in each position as a cell.
After finishing determining the movement of all products in the line, the line simulator 11 advances the timer of the line simulator 11, and repeats the operation. When all products to be input reach the end of the line, the timer is stopped, and the line simulator 11 outputs the value of the tinier as the processing completion time.
In the present embodiment, to express the setup operation, a setup cell C is arranged as a dummy device immediately before the processing equipment cell B as illustrated in
Thus, in the present embodiment, a setup determination cell D is arranged ahead of the setup cell C.
Next, a description will be given of a method taking into consideration a case where one worker performs setup operations in a plurality of lines. The fact that when performing a setup operation in one of the lines, the worker cannot perform another setup operation simultaneously is reproduced on the line simulator. As the basic layout, a plurality of lines illustrated in
In the calculations so fax, the setup operations are performed in the order of products of which the processing is completed first. In the layout in
The present embodiment enables to change the order of setup operations by the input order by providing the setup determination cell D common to a plurality of lines at the entrance of the plurality of lines to which the worker is assigned.
Then, the line simulator 11 reads the initial input order from the input order storage unit 30 (step S2).
Then, the line simulator 11 performs a process of moving a worker (step S3).
When the loop is completed, the line simulator 11 determines whether the worker i is positioned in the setup cell C (step S23). When it is determined to be “No” in step S23, the line simulator 11 determines whether there is another worker in the destination of the worker i (step S24). When it is determined to be “No” in step S24, the line simulator 11 moves the worker i to the next cell in the worker circulation route (step S25). When it is determined to be “Yes” in step S24, the line simulator 11 moves the worker i to the cell where there is no worker in the worker circulation route (step S26).
When it is determined to be “Yes” in step S23, the line simulator 11 determines whether there is a product in the setup cell C where the worker i is positioned (step S27). When it is determined to be “No” in step S27, step S24 is executed. When it is determined to be “Yes” in step S27, after step S25 is executed, or after step S26 is executed, the process returns to step S23 until i becomes m from 1. When it is determined to be “Yes” in step S27, after step S25 is executed, or after step S26 is executed, when i becomes in, the flowchart ends. Execution of the process of moving a worker allows the worker to be moved to the setup cell C where there is no worker and there is a product. In addition, the worker is made to stay in the setup cell C until the product is moved from the setup cell C where the worker is positioned.
Reference back to
When it is determined to be “Yes” in step S5, the line simulator determines whether there is a product that is not input to the processing line yet or there is a product left in the line (step S6). Specifically, it is determined whether there is a product that is not input to the processing line yet among products included in the product input order read in step S2, and whether there is a product left in the line. When at least one of them is applicable, it is determined to be “Yes”. When it is determined to be “Yes” in step S6, the line simulator 11 determines whether it is possible to input the next product to the processing line (step S7). Specifically, when there is no product in the first conveyer cell A of the line associated with the next product to be input, it is determined that it is possible to input the product. When it is determined to be “Yes” in step S7, the line simulator 11 inputs the next product to the line associated with the next product (step S8). When it is determined to be “No” in step S7 or after step S8 is executed, the process is executed again from step S3. B repeating the processes from step S3 to step S8, the product is input to the line according to the initial input order obtained in the step S2.
When it is determined to be “No” in step S5, the line simulator 11 obtains information about the cell where the product (i) is located (step S9). Note that i has a value of 1 to ip. When the total number of products on the line is two, ip is 2, and i has a value of 1 and 2. Then, the line simulator 11 determines whether the cell obtained in step S9 is the conveyer cell A, the setup determination cell D, the setup cell C. or the processing equipment cell B (step S10).
When it is determined that the cell obtained in step S9 is the conveyer cell. A in step S10, the line simulator 11 executes a process oldie conveyer cell (step S11). When it is determined that the cell obtained in step S9 is the setup determination cell D in step S10, the line simulator 11 executes a process of the setup determination cell (step S12). When it is determined that the cell obtained in step S9 is the setup cell C in step S10, the line simulator 11 executes a process of the setup cell (step S13). When it is determined that the cell obtained in step S9 is the processing equipment cell B in step S10, the line simulator 11 executes a process of the processing equipment cell (step S14).
When it is determined to be “No” in step S53, the line simulator 11 determines whether there is a worker in the setup cell C where the product is located (step S54). When it is determined to be “Yes” in step S54, the line simulator 11 increments timer (step S55). When it is determined to be “Yes” in step S53, the line simulator 11 initializes the timer for the product (step S56). Then, the line simulator 11 moves the product to the processing equipment cell B (step S57). Then, the line simulator 11 executes the process of moving a worker (step S58).
After step S55 is executed, after step S5 is executed, or when it is determined to be “No” in step SM, the flowchart ends. Execution of the process of the setup cell enables to make the product wait when there is no worker in the setup cell C when the product has been moved to the setup cell C. In addition, when there is a worker in the setup cell C when the product is moved to the setup cell C, the setup operation time can be counted.
The loop from step S9 to S14 (product-in-line loop) is repeated until the product number i becomes ip from 1. This allows one of the processes of step S11 to step S14 to proceed for all products in the processing line.
Thereafter, step S6 is executed. Every time the loop from step S5 to step S14 (time loop) is executed once, one unit time is advanced. Thus, b obtaining the number of times the time loop is looped, the completion time of the line that takes the largest time (the processing completion time) is obtained.
When it is determined to be “No” in step S6, the line simulator 11 breaks (stops) the time loop (step S15). Then, the line simulator 11 calculates the number of times the time loop is looped and outputs it as Time (step S16). Thereafter, the flowchart in
The optimization engine 10 rearranges the order of setup operations with respect to the initial input order, and calculates the processing completion time after the rearrangement, and creates, as planning data, the order of setup operations that achieves the processing completion time shorter than the processing completion time of the initial input order among the calculated processing completion times. For example, by executing the flowchart in
As illustrated in
Then, the output unit 12 outputs the processing completion time Time obtained by the line simulator 11 (step S72). Then, the creation unit 13 determines whether the processing completion time Time output by the output unit 12 is an optimal value (step S73). For example, the ere at ion unit 13 may determine that the processing completion time Time is the optimal value when the processing completion time Time is less than the processing completion time of the initial input order. Alternatively, the creation unit 13 may determine that the processing completion time Time is the optimal value when the processing completion time Time is equal to or less than a threshold value that is loss than the processing completion time of the initial input order.
When it is determined to be “No” in step S73 the order rearrangement unit 14 rearranges the setup operations with respect to the initial input order, and inputs it to the line simulator 11 (step S74). When step S74 is executed for the second time or later, one of the rearrangement candidates that are not input to the line simulator 11 yet among rearrangement candidates is input to the line simulator 11. Thereafter, the process is executed again from step S71. When step S71 is executed after step S74 is executed, the line simulator 11 uses the input order input from the order rearrangement unit 14. When it is determined to be “Yes” in step S73, the creation unit 13 stores the input order subjected to determination in the optimal order storage unit 60 (step S75). The input order in this case corresponds to the planning data indicating the order of setup operations that achieves the processing completion time that is less than the processing completion time of the initial input order.
By executing the setup operation modification process, the optimal processing completion time Time can be calculated. The processing completion time Time may be obtained with respect to each of all rearranged input orders, and the smallest value may be determined as the optimal processing completion time Time,
The input order input to the line simulator 11 directly corresponds to the order of setup operations of the worker. Therefore, by optimizing the processing completion time obtained from the line simulator 11 by rearranging the input order of products, the order of setup operations that achieves a shorter processing completion time can be obtained,
In the present embodiment, the setup operations are rearranged with respect to the initial input order according to which products are to be input to the processing line including a plurality of lines to which a product that requires a setup operation and a processing operation is to be input, setup operations being not executed with the setup operations overlapped with each other in the plurality of lines. Then, the processing completion time of the processing line after rearrangement is calculated. Among the calculated processing completion times, the order of setup operations that achieves the processing completion time less than the processing completion time of the initial input order is created as planning data. Use of this planning data reduces the processing completion time.
The display device 104 may display the planning data created by the creation unit 13. The input device. 70 may input products to the processing line according to the planning data created by the creation unit 13.
(Variation)
A case where a large number of products are to be input will be considered. When a lame number of products are to be input, it becomes difficult to solve a combinational problem. Thus, the optimal order of setup operations is obtained by rearranging the input order only in the part where the setup operations of the worker overlap and the part where the setup operations are adjacent to each other. The key point in this process is to set in advance, as the input order, the part where the setup operations of the worker overlap and the part where the setup operations are close to each other. Therefore, in the present variation, the input order of the products for which the order of setup operations is to be determined is determined in advance using a setup overlap avoiding layout illustrated in
Since the overlap avoiding layout is used, the order that reduces the processing completion time is not obtained, but the order of setup operations according to which the processing completion order of the products avoids the overlap between operations is obtained. The line simulator 11 sets this processing completion order of the products as the initial input order (step S84). Then, the line simulator 11 reads the layout for calculating the optimal order of setup operations illustrated in
Then, the order rearrangement unit 14 sets the input order of the input-order-to-be-determined products as the input variable of the optimization calculation (step S87). Then, the order rearrangement unit 14 determines whether there is an input order fixed product (step S88). When it is determined to be, “Yes” in step S88, the order rearrangement unit 14 inputs the input order fixed product first, and then arranges the input-order-to-be-determined products set as the input variables in the order in which the input-order-to-be-determined products are to be input to the line simulator 11 (step S89). When it is determined to be “No” in step S88, the order rearrangement unit 14 sets the input order of the input-order-to-be-determined product as the order of the products to be input to the line simulator 11 (step S90).
After step S88 is executed, or after step S89 is executed, the line simulator 11 obtains the processing completion time Time by executing the flowchart in
When it is determined to be “Yes” in step S91, the creation unit 13 sets the product that is to be input earliest among the input-order-to-be-determined products as a fixed product (step S95). Then, the creation unit 13 excludes the fixed product from the input-order-to-be-determined products (step S96). Then, the creation unit 13 adds the fixed product to the input order fixed product (step S97).
Then, the creation unit 13 determines whether there is still a product that is not input yet (step S98). When it is determined to be “Yes” in step S98, the creation unit 13 adds one product of the products that are not input yet to the input-order-to-be-determined product (step S99). Thereafter, the process is executed again from step S87. When it is determined to be “No” in step S98, the creation unit 13 fixed the remaining input order (step S100). Then, the creation unit 13 outputs the determined input order as the optimal order of setup operations (step S101). Thereafter, the execution of the flowchart is completed.
In the present variation, the setup operations adjacent to each other are extracted as the rearrangement candidates from the initial input order according to which products are to be input to the processing line including a plurality of lines to which a product that requires a setup operation and a processing operation is to be input, setup operations being not executed with the setup operations overlapped with each other in the plurality of lines. Then, the processing completion time of the processing line after rearrangement is calculated. Among the calculated processing completion times, the order of setup operations that achieves the processing completion time less than the processing completion time of the initial input order is created as planning data. Use of this planning data reduces the processing, completion time. In addition, even when a large number of products are to be input, the processing completion time can be optimized efficiently.
In each of the above examples, the order rearrangement unit 14 functions as an example of a rearrangement unit that rearranges setup operations with respect to the initial input order according to which products are to be input to a processing line including a plurality of lines to which a product that requires a setup operation and a processing operation is to be input, setup operations being not executed with the setup operations overlapped with each other in the plurality of lines. The line simulator 11 functions as an example of a calculation unit that calculates a processing completion time of the processing line after rearrangement by the rearrangement unit. The creation unit 13 functions as an example of a creation unit that creates an order of setup operations that achieves a processing completion time less than a processing completion time of the initial input order among the processing completion time calculated by the calculation unit. The display device 104 functions as an example of a display device that displays the planning data. The input device 70 functions as an input device, that inputs the products to the processing line according to the planning data created by the creation unit.
All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are, to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various change, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.
This application is a continuation application of International Application PCT/JP2018/048485 filed on Dec. 28, 2018 and designated the U.S., the entire contents of which are incorporated herein by reference.
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Number | Date | Country | |
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Parent | PCT/JP2018/048485 | Dec 2018 | US |
Child | 17231079 | US |