JP2001236110A - Production process layout generating device, its method and computer readable recording medium in which program to make computer function as production process layout generating device is recorded - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production process layout generating method to perform layout design of production processes in consideration of fluctuation of production states. SOLUTION: Horizontal and vertical length of rectangles to be occupied by each process and process numbers (order of processes) are inputted by every period (S2). Plural master chromosomes (initial chromosomes) are generated by defining the process numbers as genes (S4). Candidates for plural chromosomes are calculated so that distribution cost is minimized according to GA for each period from the first period to the N-th period (S6). Layouts are selected one by one from N periods and plural combinations of layouts are calculated so that the distribution cost and arrangement changing cost for N periods are minimized (S8). The chromosomes to minimize the distribution cost and the arrangement changing cost are selected among plural obtained chromosomes (S10). An actual process layout is decided by N chromosomes selected by a processing in S10 (S12).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a production process layout creating apparatus and method for creating a layout of each process of a production line in a factory, and a computer-readable recording program for causing a computer to function as the production process layout creating device. It relates to a possible recording medium. In particular, the present invention relates to a production process layout creation device and method for creating an optimal layout on the premise of a production process layout change, and a computer-readable recording medium that records a program for causing a computer to function as the production process layout creation device.

[0002]

2. Description of the Related Art Automation of a production line in a factory has been advanced, and it has become important how to efficiently arrange production machines such as robots in a limited space and perform production efficiently.

[0003] For this reason, there have been proposed some layout creating apparatuses for laying out each process. Japanese Patent Application Laid-Open No. 7-160739 discloses a production line layout creating apparatus for automatically determining the order of processes, the connection between processes and equipment, and creating a layout of processes.

[0004]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open No. 7-1
The production line layout creating apparatus disclosed in Japanese Patent Application Laid-Open No. 60739 is intended only for creating a layout in a single period, and cannot change the layout according to a change in the production situation. For example, if the production quantity changes greatly, the flow of things in the factory becomes complicated, and the layout must be designed again. However, the layout is not designed in consideration of the fluctuation of the production situation. For this reason, there is a problem that an arrangement change cost (cost associated with equipment movement at the time of layout change) is generated, which affects production efficiency.

[0005] In addition, layout design is performed without taking into account the passages and the like that always exist in an actual factory. Therefore, there is a problem that the created layout cannot be used as it is.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a production process layout creating apparatus for designing a layout of a production process in consideration of a change in a production situation, and a computer using the same. It is an object of the present invention to provide a computer-readable recording medium in which a program for functioning as a computer is recorded.

Another object of the present invention is to provide a production process layout creating apparatus capable of directly using a created layout and a computer-readable recording medium recording a program for causing a computer to function as the production process layout creating apparatus. It is to provide.

[0008]

According to a first aspect of the present invention, a production process layout creating apparatus creates a layout of a production process over a plurality of periods. The production process layout creation device includes a first layout creation unit for creating a layout of a plurality of production processes according to a predetermined first condition for each of a plurality of periods, and a first layout creation unit. A second layout creating means for creating a layout of a production process in each period from a plurality of layouts obtained in each period in accordance with a second condition in consideration of a layout change over a plurality of periods. Including.

A plurality of layout candidates are created for each period, and the layout for each period is determined so that the layout change cost of the layout is reduced. Therefore, when a monthly production plan is determined in advance, a layout can be created in consideration of a change in production status. Therefore, the production efficiency of products and the like can be improved.

According to a second aspect of the present invention, in addition to the configuration of the first aspect of the invention, the first layout creating means further comprises:
The production process and the layout of the production process are represented by genes and chromosomes in the genetic algorithm, respectively, and the layout of the plurality of production processes is created for each of the plurality of periods according to the genetic algorithm.

According to a third aspect of the present invention, in addition to the configuration of the first or second aspect of the invention, the second layout creating means includes a layout of the production process created by the first layout creating means. Genes in the genetic algorithm are extracted one by one from a plurality of periods to form a chromosome, and a layout of a production process in each period is created according to the genetic algorithm.

According to a fourth aspect of the present invention, in addition to the configuration according to any one of the first to third aspects, the first layout creating means is configured to control the physical distribution between the production processes for each of a plurality of periods. Means for creating a layout of a plurality of production processes to reduce costs.

The layout of the production process is created so that the distribution cost in each period is reduced. Therefore, production efficiency of products and the like can be improved.

According to a fifth aspect of the present invention, in addition to the configuration according to any one of the first to fourth aspects, the second layout creating means is connected to the first layout creating means,
Means for creating a layout of the production process in each period from a plurality of layouts obtained in each period so as to reduce the cost of changing the arrangement of the production process.

[0015] The layout change cost can be minimized throughout the period. Therefore, production efficiency of products and the like can be improved.

According to a sixth aspect of the present invention, in addition to the configuration of the first aspect of the invention, the first layout creating means considers a location where a production process cannot be arranged in a factory. , Create the layout of the production process.

A layout design is performed in consideration of an unplaceable place such as a passage existing in an actual factory. Therefore, the created layout can be directly applied to an actual factory.

According to a seventh aspect of the present invention, there is provided a production process layout creating method according to the first aspect, for creating a layout of a plurality of production processes for each of a plurality of periods in accordance with a first predetermined condition. Layout creation means;
A second layout generating means for generating a layout of a production process in each period from a plurality of layouts obtained in each period in accordance with a second condition considering a layout change over a plurality of periods. This is used in a production process layout creation device including a layout creation means. The production process layout creation method includes, for each of a plurality of periods, a step of creating a layout of a plurality of production processes according to a first condition, and a plurality of layouts obtained in each period according to a second condition. Creating a layout of the production process for the period.

A plurality of layout candidates are created for each period, and the layout for each period is determined so as to reduce the layout change cost. Therefore, when a monthly production plan is determined in advance, a layout can be created in consideration of a change in production status. Therefore, the production efficiency of products and the like can be improved.

A computer-readable recording medium according to the invention described in claim 8 records a program for causing a computer to function as a production process layout creating apparatus that creates a layout of a production process over a plurality of periods. The production process layout creation device includes a first layout creation unit for creating a layout of a plurality of production processes according to a predetermined first condition for each of a plurality of periods, and a first layout creation unit. A second layout creating means for creating a layout of a production process in each period from a plurality of layouts obtained in each period in accordance with a second condition in consideration of a layout change over a plurality of periods. Including.

A plurality of layout candidates are created for each period, and the layout for each period is determined so that layout changes are reduced. Therefore, when a monthly production plan is determined in advance, a layout can be created in consideration of a change in production status. Therefore, the production efficiency of products and the like can be improved.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a production process layout creating apparatus 10 according to an embodiment of the present invention includes a computer 11, a keyboard 15 and a mouse 16 for giving instructions to the computer 11, a computer, 11
A display 12 for displaying a result calculated by the computer 11, a magnetic tape device 13 for reading a program executed by the computer 11, respectively, a CD-ROM
(Compact Disc-Read Only Memory) device 17 and communication modem 19 are included.

A program for creating a production process layout is recorded on a magnetic tape 14 or a CD-ROM 18, which is a recording medium readable by the computer 11, and read by a magnetic tape device 13 and a CD-ROM device 17, respectively. Alternatively, it is read by the communication modem 19 via the communication line.

Referring to FIG. 2, computer 11 includes a CPU (Central Processing Unit) 20 for executing a program read via magnetic tape device 13, CD-ROM device 17, or communication modem 19, and a computer. ROM (Read Only Memory) 21 for storing other programs and data necessary for the operation of
And a RAM (Random Access Memo) for storing the program, parameters for executing the program, calculation results, and the like.
ry) 22 and a magnetic disk 23 for storing programs, data, and the like.

Magnetic tape device 13, CD-ROM device 1
7 or the program read by the communication modem 19 is executed by the CPU 20.

The area occupied by each step is represented by a rectangle, and the layout position of that step is represented by the coordinates of the four corners of the rectangle. For example, referring to FIG. 3, step 4 of a step represented by a rectangle having a vertical length of 3 and a horizontal length of 5
The coordinates of the corner are, for example, (0, 0), (0, 3),
It is represented as (5,3), (5,0).

The layout of each step is represented as a chromosome in a genetic algorithm (hereinafter referred to as "GA"). Here, the genes constituting the chromosome correspond to the respective steps. The layout is determined by the arrangement order of the genes.

Referring to FIG. 4, for example, chromosome (1,
The layout represented by (4,3,5,2) is the process 1,
By inputting a rectangle representing each process from the upper right of the rectangle 30 representing the factory in the order of step 4, step 3, step 5, and step 2 and shifting to the bottom at the stage where the rectangle has been moved to the bottom, can get.

Referring to FIG. 4A, a rectangle representing step 1 is inserted from the upper right of rectangle 30 and shifted to the left when the process is performed to the bottom. Referring to FIG. 4B, next, a rectangle representing step 4 is input from the upper right, and 1
When it reaches the bottom, it shifts to the left. When the same processing is sequentially performed on rectangles representing steps 3, 5, and 2, a layout of a production process as shown in FIG. 4C is finally obtained.

If there is a passage in the factory,
, The layout of the process is performed with the passage being avoided.

Referring to FIG. 6, a description will be given of a layout creation process in a plurality of periods from the first period to the N-th period (N is an integer of 2 or more) using GA. It is assumed that the number of steps in each period is five, but the number is not limited to five.

First, for each period, the vertical length, the horizontal length, the process number (the order of the processes) of the rectangle occupied by each process, the material flow rate in each period between the processes, and the arrangement change of each process. The cost is input (S2).

Using the process number as a gene, a parent chromosome (initial chromosome) of the number of processes × 10 (here, 50) is created (S4). For example, one of the parent chromosomes is (1,4,
2, 3, 5).

For each period from the first period to the Nth period,
According to GA, the number of processes x
Ten chromosome candidates are obtained (S6). The distribution cost is obtained by multiplying the material flow rate between the processes by the moving distance between the processes. Referring to FIG. 5, when a passage is provided between the steps, the movement between the steps is easier than when there is no passage. For this reason, regarding the moving distance of the passage portion, the actual moving distance is multiplied by a correction coefficient of 1/2.

By this processing, for example, (1, 3, 2, 4, 5), (4, 2,
3,5,1), (4,2,1,5,3), etc. × 1
0 (50) chromosome candidates are obtained.

Referring to FIG. 7, the processing in S6 will be described in detail. The following processing is performed independently for each period. For each of the number of steps × 10 parent chromosomes created in the processing of S4, the Xth gene and the Yth gene are replaced, and the number of steps × 10 × 2 chromosomes are created together with the parent chromosome ( S22). However,
X and Y are random natural numbers that maximize the number of steps. Here, it is an integer of 1 or more and 5 or less. When creating a chromosome, the created chromosome is stored in the RAM 22 so as not to create the same chromosome as the already created chromosome.
Is stored in

From the number of steps × 10 × 2 chromosomes, the number of steps × 10 chromosomes are selected in ascending order of the value of the objective function described later (S24). The objective function indicates the sum of physical distribution costs between processes that can be combined, and is represented by Expression (1).

[0038]

(Equation 1)

After the number of steps × 10 chromosomes is selected, it is determined whether or not an ending condition described later is satisfied (S26). If the ending condition is satisfied (YE in S26)
S), the processing of S6 ends. If the termination condition is not satisfied (NO in S26), the processing from S22 onward is repeated. The case where the termination condition is satisfied means the case where the solution converges. Here, when the improvement of the value of the objective function is less than 5%, it is determined that the solution has converged. By the processing up to this point, an optimal layout of the number of steps × 10 is obtained for each period.

Referring to FIG. 6 again, layouts are selected one by one from N periods, and a combination of layouts is determined such that the distribution cost and the layout change cost over the N periods are minimized (S8). . Here, the arrangement change cost refers to the moving cost of the devices and equipment used in each process. For example, it is calculated from a dismantling cost per unit area, a moving cost converted from a moving distance, an installation cost at a moving destination, and the like.

Referring to FIG. 8, the processing in S8 will be described in detail. Here, it is assumed that the layout (chromosome) is numbered in order from the smallest value of the objective function shown in Expression (1) for each period.

The number corresponding to the order of the value of the objective function in equation (1) is defined as a gene. One gene is selected from each period, and a chromosome having N genes is created. Such chromosomes (parent chromosomes, initial chromosomes) are created by the number of steps × 10 (here, 50) (S30). For example, one of the parent chromosomes is represented as (3, 2,..., 4).
This is because a layout having the third smallest value of the objective function of the equation (1) is selected from the layout candidates of the first term, and an objective function of the equation (1) is selected from the candidates of the layout of the second term. Indicates that the layout having the second smallest value is selected. Hereinafter, it is shown that the layout is selected according to the same rule until the N-th period.

In the same manner as in the process of S22 in FIG. 7, a process number × 10 × 2 chromosomes are created from the process number × 10 parent chromosomes (S32).

Out of the number of steps × 10 × 2 chromosomes, the values of the objective function (described later) representing the sum of the distribution cost and the arrangement change cost throughout all periods are in ascending order.
The number of steps × 10 chromosomes is selected (S34). The objective function is represented by equation (2).

[0045]

(Equation 2)

After the number of steps × 10 chromosomes is selected, it is determined whether or not the same termination condition as in S26 of FIG. 7 is satisfied (S36). If the termination condition is satisfied (YES in S36), the processing in S8 ends. If the termination condition is not satisfied (NO in S36), the processing from S32 is repeated.

Referring again to FIG. 6, one chromosome having the minimum value of the objective function of equation (2) is selected from the number of steps × 10 chromosomes obtained in the processing of S8, and the chromosome is selected. Chromosomes representing the layout of each period are selected (S
10). For example, it is assumed that the chromosome with the minimum value of the objective function of Expression (2) is (1, 2,..., 2, 3). As the chromosome representing the layout of the first stage, the chromosome (1, 3, 2, 4,
5) is selected from the candidates obtained in the processing of S6. As the chromosome representing the layout of the second stage, the chromosome (3,
1, 2, 5, 4) are selected from the candidates obtained in the processing of S6. Similarly, the chromosomes representing the layout are respectively selected until the N-th period.

An actual process layout is determined from the N chromosomes selected in the process of S10 (S12).

With the above-described processing, a process layout over a plurality of periods is created. Therefore, for example, when a monthly production plan is determined in advance, a layout can be created in consideration of a change in production status. Therefore, production efficiency can be improved while minimizing distribution costs and arrangement change costs.

When the production plan is changed on the way, the layout can be designed again.

Further, the layout is designed in consideration of the passage existing in the factory. Therefore, the created layout can be directly applied to an actual factory.

It should be understood that the embodiments disclosed this time are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[Brief description of the drawings]

FIG. 1 is an external view of a layout creation device 10 according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a computer according to the embodiment of the present invention.

FIG. 3 is a diagram showing an area occupied by a process.

FIG. 4 is a diagram for explaining a relationship between a chromosome and a layout in the genetic algorithm.

FIG. 5 is a diagram showing an example of a process layout in a factory having a passage.

FIG. 6 is a flowchart of a layout creation process.

FIG. 7 is a flowchart for describing the processing in S6 of FIG. 6 in detail.

FIG. 8 is a flowchart for explaining the processing in S8 of FIG. 6 in detail;

[Explanation of symbols]

Reference Signs List 10 production process layout creation device, 11 computer, 12 display, 13 magnetic tape device, 14
Magnetic tape, 15 keyboard, 16 mouse, 17
CD-ROM device, 18 CD-ROM, 19 communication modem, 20 CPU, 21 ROM, 22 RAM, 2
3 magnetic disks, 30 rectangles.

Claims (8)

[Claims] 1. A production process layout creating apparatus for creating a layout of a production process over a plurality of periods, wherein a layout of a plurality of production processes is created for each of the plurality of periods according to a predetermined first condition. First layout creating means for creating, and the plurality of layouts connected to the first layout creating means and obtained in each period according to a second condition taking into account a layout change over the plurality of periods. And a second layout creating means for creating a layout of the production process in each period. 2. The method according to claim 1, wherein the first layout creating means expresses the production process and the layout of the production process by a gene and a chromosome in a genetic algorithm, respectively, and, in accordance with the genetic algorithm, 2. The production process layout is created.
2. The production process layout creation device according to 1. 3. The method according to claim 2, wherein the second layout creating means uses the layout of the production process created by the first layout creating means as a gene in a genetic algorithm, takes out the genes one by one from the plurality of periods, and The production process layout creating apparatus according to claim 1, wherein a layout of the production process in each period is created according to a genetic algorithm. 4. The first layout creating unit includes a unit for creating a layout of a plurality of production processes such that a distribution cost between production processes is reduced for each of the plurality of periods. Item 4. The production process layout creation device according to any one of Items 1 to 3. 5. The second layout creating means is connected to the first layout creating means, and is obtained in each period so as to reduce an arrangement change cost generated when an arrangement in a production process is changed. 5. The production process layout creating apparatus according to claim 1, further comprising means for creating a layout of a production process in each period from said plurality of layouts. 6. The production process layout creation according to claim 1, wherein said first layout creation means creates a layout of the production process in consideration of a place where the production process cannot be arranged in the factory. apparatus. 7. A first layout creating means for creating a layout of a plurality of production processes according to a first predetermined condition for each of a plurality of periods, and connected to the first layout creating means. And a second layout creating means for creating a layout of a production process in each period from the plurality of layouts obtained in each period according to a second condition taking into account the layout change over the plurality of periods. A production process layout creation method used in a production process layout creation device, comprising: for each of the plurality of periods, creating a layout for a plurality of production processes according to the first condition; Creating a layout of a production process in each period from the plurality of layouts obtained in each period according to a condition. How to make out. 8. A computer-readable recording medium recording a program for causing a computer to function as a production process layout creating device that creates a layout of a production process over a plurality of periods, wherein the production process layout creating device comprises: A first layout creation unit for creating a layout of a plurality of production processes for each of the plurality of periods in accordance with a predetermined first condition; and And a second layout creating means for creating a layout of a production process in each period from the plurality of layouts obtained in each period in accordance with a second condition taking into account a layout change over the period. A readable recording medium.