JPH11306162A - Production simulation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simulate the autonomous actions of workers by producing a rule for every worker to define a place to move next and a job to do next every time a job is over and performing the simulation based on the produced rule. SOLUTION: A product is moved onto a work bench P2 for every worker and every time the job of a process 1 is over (step 1). The process 1 proceeds to a process 10 (step 3) if an in-process product exists at an in-process buffer Q4 (Yes of step 2). If no in-process product exists at the buffer Q4 (NO of step 2), the process 1 proceeds to a process 2 (step 4). Thus, a rule is produced for every job to be done and the simulation is performed based on this rule. Then a variable included in the rule is optimized by learning.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a production simulation method capable of performing a suitable simulation for a human-centered production system.

[0002]

2. Description of the Related Art In a conventional production line system using a conveyor line or the like, each worker is a single worker,
The work procedure for each worker was fixed. Also, there was no movement of workers and no cooperation among workers. In other words, in the conventional production line system, the worker only repeats a limited work in a certain order without moving from one fixed place. For this reason, the variation in the amount of work between workers was large.

In recent years, a human-centered production line system utilizing a U-shaped line or the like has been developed. In a human-centered production line system, each worker takes on a plurality of different tasks as multi-skilled workers, and in some cases, moves through a plurality of places to perform the tasks. Work is usually performed in a certain order, but at the discretion of the worker according to the situation at that time,
The work order and contents can be flexibly changed.

[0004] In the conventional production method, a target work (parts or products) is moved by a machine such as a conveyer. However, in a human-centered production line system, most of the movement is performed by a worker himself / herself. Will be In addition, human intellectual behavior (hereinafter referred to as coordination) such as cooperation between people, mutual assistance (helping each other), and exchange of intention and information is used. For this reason, the variation in the work amount between the workers is reduced.

[0005] Specific examples of cooperation include the following.・ If there is a person who is late for work, help him or her. As a result, the work amount is averaged, and the waste of the hand is reduced.・ Several people take turns in or work together.・ If your work is late, increase the work speed.・ If a problem occurs, call another worker for help.

Meanwhile, the current production simulation method mainly focuses on facilities (machines, conveyors, AGC, etc.) and works (materials, parts, products, etc.). Then, the worker is called when an event occurs in the equipment or work, and performs the work.

With the current production simulation method, it is difficult to simulate the autonomous behavior of a worker in a human-centered production line system.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a production simulation method capable of simulating the autonomous behavior of a worker in a human-centered production line system.

[0009]

SUMMARY OF THE INVENTION A production simulation method according to the present invention is a production simulation method for simulating at least a human-centered production line system in which workers assist each other. In each step, a step of creating a rule for defining a place to be moved next and a work to be performed next each time work is completed, and status information including a work progress status of each worker and a current status of the work, A step of performing a simulation based on the rule.

[0010] The rule for at least one worker describes a condition expression including a variable as predetermined information of the situation information. The above variables may be optimized so as to improve the variation in the working time among the workers. The rule is created based on, for example, a process in charge for each worker, a process for helping another worker for each worker, and the work time of each process.

[0011]

Embodiments of the present invention will be described below.

FIG. 1 shows a simulation model of a U-shaped line (with cooperation) which is an example of a human-centered production line system.

In FIG. 1, reference numerals P1 to P10 denote worktables, respectively. The steps performed on the work tables P1 to P10 are referred to as first to tenth steps. Also, Q
0 to Q4 indicate in-process buffers. A, B,
C indicates a worker.

A solid arrow a indicates a normal moving path of the worker A, and a broken arrow a 'indicates a moving path when the worker A assists the worker B. Solid arrow b
Indicates a normal movement route of the worker B. A solid arrow c indicates a normal moving path of the worker C, and a broken arrow c ′ indicates a moving path when the worker C assists the worker B.

FIG. 2 shows a work procedure of a worker. Table 1 shows the required time for each step and the person in charge of each step. In order to make it easier to understand the features of the U-shaped line (with cooperation) according to this embodiment, FIG.
, Straight line and U-shaped line (no coordination)
The work procedure for and the person in charge of each process are also described.

[0016]

[Table 1]

A simulation method performed on a U-shaped line (with cooperation) will be described in detail.

First, based on the process in charge for each worker, the process for assisting each worker for each other (helping process), and the working time of each process, a place to be moved next for each worker, Create rules to determine what work to do.
And a simulation is performed using this rule,
The variables in the rules are optimized by learning.

The steps in charge of each worker are as follows. Worker A: Step 1, Step 2, Step 10 Worker B: Step 3, Step 4, Step 5, Step 6 Worker C: Step 6, Step 7, Step 8

The process of assisting each worker is as follows. Worker A: Process 9 Worker B: None Worker C: Process 5

The working time of each step is as shown in Table 1.

3 to 6 show the rules of the worker A.

FIG. 3 shows a rule applied when the worker A completes the work of the step 1. Worker A performs process 1
Is completed, the product is moved to the worktable P2 (step 1). If there is an in-process product in the in-process buffer Q4 (YES in step 2), the process 1
0 (step 3), and if there is no in-process product in the in-process buffer Q4 (NO in step 2),
Move to step 2 (step 4).

FIG. 4 shows a rule applied when the worker A completes the work of the step 2. Worker A performs process 2
When the work is completed, the product
1 (step 5). In-process buffer Q0
If there is a work in process at
S), move to step 1 (step 7). If there is no in-process product in the in-process buffer Q0 (NO in step 6) and there is any in-process product in the in-process buffer Q4 (YES in step 8), the process moves to step 10 (step 9). ). If no in-process product exists in the in-process buffer Q0 (NO in step 6) and if no in-process product exists in the in-process buffer Q4 (NO in step 8), the product is stored in the in-process buffer Q0. Waits (step 10).

FIG. 5 shows rules that are applied when the worker A completes the work of the step 10. When the worker A completes the work of the step 10, the product is carried out (step 11). The total number of in-process products of the worker B (the total number of in-process products in the in-process buffer Q1 and the in-process buffer Q3) is larger than the variable X1 (YE in step 12).
S) and the total number of in-process products of the worker A (the total number of in-process products in the in-process buffer Q0 and the in-process buffer Q4) is smaller than the variable Y1 (YE in step 13).
S), and if worker B is not working in step 9 (NO in step 14), the process moves to step 9 (step 1).
5).

If the total number of in-process products of the worker B is smaller than the variable X1 (NO in step 12) and there is an in-process product in step 2 (YES in step 16), the process moves to step 2 ( Step 17).

The total number of in-process products of the worker B is less than the variable X1 (NO in step 12), no in-process product exists in the process 2 (NO in step 16), and the in-process buffer Q0 If there is a work-in-progress (YES in step 18), the process moves to step 1 (step 19).

The total number of in-process products of the worker B is smaller than the variable X1 (NO in step 12), no in-process product exists in the process 2 (NO in step 16), and the in-process buffer Q0 If there is no in-process product (NO in step 18), the process waits until a product comes to the in-process buffer Q0 (step 20).

FIG. 6 shows a rule applied when the worker A completes the work of the step 9. Worker A performs step 9
When the work is completed, the product
4 (step 21). If there is an in-process product in step 2 (YES in step 22), step 2
(Step 23).

If there is no work in process 2 (NO in step 22) and there is work in buffer W0 (YES in step 24), the process moves to step 1. (Step 25).

If there is no in-process product in step 2 (NO in step 22) and if no in-process product exists in the in-process buffer Q0 (N in step 24)
O), and wait until a product comes to the in-process buffer Q0 (step 26).

7 to 10 show the rules of the worker B.

FIG. 7 shows the rules applied when the worker B completes the work of the step 3. Worker B is in process 3
Is completed, the product is moved to the worktable P4 (step 31).

If worker A is working in step 9 (YES in step 32) and worker C is working in step 5 (YES in step 33), the process moves to step 4 (step 33). 34).

The worker A is not working in step 9 (NO in step 32), no in-process product exists in the in-process buffer Q3 (NO in step 35), and the worker C is in step 5 If the operation is being performed (YES in step 33), the process moves to step 4 (step 34).

If the worker A is not working in step 9 (NO in step 32) and there is an in-process product in the in-process buffer Q3 (YES in step 35),
Move to step 9 (step 36).

Worker A is working in step 9 (YES in step 32), worker C is not working in step 5 (NO in step 33), and there is a work-in-progress on work table P5. If not (NO in step 37),
Move to step 4 (step 34).

Worker A is working in process 9 (YES in step 32), worker C is not working in process 5 (NO in step 33), and there is a work-in-progress on worktable P5. If yes (YES in step 37),
Move to step 5 (step 38).

FIG. 8 shows a rule applied when the worker B completes the work of the step 4. Worker B performs process 4
When the operation is completed, the product is moved to the worktable P5 (step 39).

If there is an in-process product in the in-process buffer Q1 (YES in step 40), the process moves to step 3 (step 41).

There is no in-process product in the in-process buffer Q1 (NO in step 40), worker A is working in step 9 (YES in step 42), and worker C is in step 5. If the operation is in progress (step 43
YES), and waits until a product comes to the in-process buffer Q1 (step 44).

If there is no in-process product in the in-process buffer Q1 (NO in step 40) and the worker A is not working in step 9 (NO in step 42), the in-process buffer Q3 is in process. If there is no product (NO in step 45) and the worker C is working in step 5 (YES in step 43), the in-process buffer Q
The process waits until the product arrives at 1 (step 44).

If there is no in-process product in the in-process buffer Q1 (NO in step 40) and the worker A is not working in step 9 (NO in step 42), the in-process buffer Q3 is in process. If a product is present (YES in step 45), the process moves to step 9 (step 4).
6).

There is no in-process product in the in-process buffer Q1 (NO in step 40), worker A is working in step 9 (YES in step 42), and worker C is in step 5. Is not working (N in step 43)
O) If there is no in-process product on the worktable P5 (NO in step 47), the process waits until a product comes to the in-process buffer Q1 (step 44).

There is no in-process product in the in-process buffer Q1 (NO in step 40), worker A is working in step 9 (YES in step 42), and worker C is in step 5 Is not working (N in step 43)
O) If there is a work-in-progress on the worktable P5 (YES in Step 47), the process moves to Step 5 (Step 48).

FIG. 9 shows the rules applied when the worker B completes the work of the step 5. Worker B is in process 5
When the operation is completed, the product is moved to the worktable P6 (step 49).

If there is a work-in-progress on the worktable P4 (YES in step 50), the process moves to step 4 (step 51).

There is no in-process product on the worktable P4 (NO in step 50), and the in-process buffer Q1
If there is any in-process product (YES in step 52), the process moves to step 3 (step 53).

No in-process product exists on the worktable P4 (NO in step 50), and the in-process buffer Q1
No in-process product exists (N in step 52).
O) If the worker A is working in step 9 (YES in step 54), the process waits until a product comes to the in-process buffer Q1 (step 55).

There is no in-process product on the worktable P4 (NO in step 50), and the in-process buffer Q1
No in-process product exists (N in step 52).
O) If the worker A is not working in the process 9 (NO in step 54) and there is no in-process product in the in-process buffer Q3 (NO in step 56), the in-process buffer Q1 (Step 55).

There is no in-process product on the worktable P4 (NO in step 50), and the in-process buffer Q1
No in-process product exists (N in step 52).
O) If the worker A is not working in step 9 (NO in step 54) and there is a work-in-progress in the work-in-process buffer Q3 (YES in step 56), the process moves to step 9 (Step 57).

FIG. 10 shows a rule applied when the worker B completes the work of the step 9. When the worker B completes the work of the step 9, the product is moved to the in-process buffer Q4 (step 58).

The worker C is working in the process 5 (YES in step 59), and there is no work-in-progress on the worktable P4 (NO in step 60), and the work-in-progress buffer Q1 is in process. The product does not exist (step 61
If NO, and there is no in-process product in the in-process buffer Q3 (NO in step 62), the process waits until a product arrives in the in-process buffer Q3 (step 6).
3).

The worker C is not working in the step 5 (NO in step 59), and there is no work-in-progress on the worktable P5 (NO in step 64), and the work-in-progress on the worktable P4. Does not exist (NO in step 60), no in-process product exists in the in-process buffer Q1 (NO in step 61), and no in-process product exists in the in-process buffer Q3. (NO in step 62), the process waits until a product comes to the in-process buffer Q3 (step 63).

If the worker C is not working in step 5 (NO in step 59) and there is a work-in-progress on the worktable P5 (YES in step 64), the process moves to step 5 (step 64). Step 65).

The worker C is not working in the step 5 (NO in step 59), and there is no work-in-progress on the worktable P5 (NO in step 64), and the work-in-progress on the worktable P4. Exists (YE in step 60).
S), proceed to step 4 (step 66).

The worker C is not working in the process 5 (NO in step 59), no work-in-progress is present on the worktable P5 (NO in step 64), and the work-in-progress is present on the worktable P4. Does not exist (NO in step 60), and there is a work-in-progress in the work-in-process buffer Q1 (YES in step 61), the process moves to step 3 (step 67).

The worker C is not working in the process 5 (NO in step 59), no work-in-progress is present on the worktable P5 (NO in step 64), and the work-in-progress is stored on the worktable P4. Does not exist (NO in step 60), no in-process product exists in the in-process buffer Q1 (NO in step 61), and there is an in-process product in the in-process buffer Q3. (Y in step 62
ES), and the operation of Step 9 is continued (Step 68).

FIGS. 11 to 13 show the rules of the worker C. FIG.

FIG. 11 shows the rules applied when the worker C completes the work in step 6. When the worker C completes the work of the step 6, the product is moved to the worktable P7 (step 71).

The total number of in-process products of the worker B (the total number of in-process products in the in-process buffer Q1 and the in-process buffer Q3) is larger than the variable X2 (YE in step 72).
S) and the total number of in-process products of the worker C (the total number of in-process products in the in-process buffer Q2) is smaller than the variable Y2 (YES in step 73), and the worker B is not working in step 5. If (NO in step 74), the process moves to step 5 (step 75).

If the total number of in-process products of the worker B is smaller than the variable X2 (NO in step 72) and there is an in-process product in step 8 (YES in step 76), the process moves to step 8 ( Step 77).

If the total number of in-process products of the worker B is smaller than the variable X2 (NO in step 72) and there is no in-process product in step 8 (NO in step 76), the process moves to step 7 ( Step 78).

FIG. 12 shows the rules applied when the worker C completes the work of the step 7. When the worker C completes the work of the step 7, the product is moved to the worktable P8 (step 79).

If there is any in-process product in the in-process buffer Q2 (YES in step 80), the process moves to step 6 (step 81).

If there is no in-process product in the in-process buffer Q2 (NO in step 80), the process moves to step 8 (step 82).

FIG. 13 shows the rules applied when the worker C completes the work in step 8. When the worker C completes the work of the step 8, the product is moved to the in-process buffer Q3 (step 83).

If there is any in-process product on the worktable P7 (YES in step 84), the process moves to step 7 (step 85).

If there is no in-process product on the workbench P7 (NO in step 84) and there is any in-process product in the in-process buffer Q2 (Y in step 86)
ES), and proceeds to step 6 (step 87).

If there is no in-process product on the workbench P7 (NO in step 84) and there is no in-process product in the in-process buffer Q2 (NO in step 86), the in-process buffer It waits until a product comes to Q2 (step 88).

The simulation is performed based on the situation information including the work progress of each worker and the current situation of the work, and the above rules. Also, variables X1, X2, Y1,
Y2 was optimized such that the work time ratios of the workers A, B, and C were the same.

FIG. 14A shows a simulation result of a straight line, and FIG. 14B shows a U-shaped line (without cooperation).
FIG. 14 (c) shows a simulation result of a U-shaped line (with cooperation).

FIG. 14 shows the ratio of the required working time per cycle of the worker in each model.

First, in order to see a change due to a difference in line layout which is a physical factor, a straight line (FIG.
(A)) and a U-shaped line (without cooperation) (FIG. 14 (b)) are compared.

The straight line has a large variation in the working time among the workers, whereas the worker B having the longest working time per cycle is 48.9 seconds, whereas the shortest C is
Only 36.9 seconds, about 75% of the time. In addition, workers A and B are provided with work tables P4 to P4, respectively.
1. Karate return (idle walking) occurs during the movement between the worktables P8 and P5, which results in a waste time of 8% each, which causes a reduction in efficiency.

On the other hand, on the U-shaped line (without coordination), the worker A who has the longest working time is 49.4 seconds and the worker A who is short is 39.4 due to improvement of the line balance.
Seconds and work time have been improved to about 85%, and karate recovery has been eliminated.

Next, in order to clarify the effect of the cooperative action of the person, which has been difficult to evaluate in the conventional simulation, a comparison is made with the same U-shaped line layout depending on whether or not there is help. That is, the U-shaped line (without cooperation) and the U-shaped line (with cooperation) are compared.

With the introduction of cooperative work on the U-shaped line,
In the character line (with coordination), the work time between the workers is averaged, there is almost no variation, and the wasteful time of karate return and standby is greatly reduced. Work time is the longest A
The shortest B is 41.8 seconds and 97% for 42.8 seconds
And the difference in working time per cycle is only 1 second.

As described above, it was confirmed that the introduction of the cooperative work to the U-shaped line greatly contributed to the inequality between workers and the elimination of waste.

In order to compare the overall efficiency of each model, the average cycle time, the line organization efficiency, and the number of shipments per hour were obtained based on Equation 1. Table 2 shows the results.
Shown in The closer the line formation efficiency is to 100%, the better the line balance and the higher the production efficiency.

[0081]

[Table 2]

[0082]

(Equation 1)

As described above, the line knitting efficiency of the straight line is limited to 80.6% due to the variation of the working time among workers and the occurrence of karate return. In contrast, the U-shaped line (without coordination) averages the working time,
Eliminating karate returns has improved line organization efficiency to 92% and increased shipments by about 15%.

In the U-shaped line (with coordination) in consideration of coordination, the knitting efficiency of the line has been dramatically improved to 98.9%, which is almost wasteless, by correcting unfairness among workers. . The number of shipments is 7% more than the U-shaped line (without cooperation) that does not support each other, and is about 24% higher than that of the straight line, confirming that cooperation contributes greatly to improving productivity.

As described above, it was confirmed that the simulation can be used to model the human cooperative behavior in human-centered production and to verify the cooperative behavior using the rule description. Furthermore, by comparing the results of simulation experiments, it was possible to confirm the effect of improving productivity by introducing cooperative (helping) behavior.

[0086]

According to the present invention, it is possible to simulate the autonomous behavior of a worker in a human-centered production line system.

[Brief description of the drawings]

FIG. 1 shows a simulation model of a U-shaped line (with cooperation).

FIG. 2 is a schematic diagram showing a work procedure of a worker.

FIG. 3 is a flowchart illustrating a rule applied when an operator A completes the operation of step 1.

FIG. 4 is a flowchart showing rules applied when the worker A completes the work of step 2.

FIG. 5 is a flowchart showing a rule applied when an operator A completes the operation of step 10.

FIG. 6 is a flowchart showing a rule applied when the worker A completes the work of step 9;

FIG. 7 is a flowchart showing a rule applied when the worker B completes the work of step 3;

FIG. 8 is a flowchart showing a rule applied when a worker B completes the work of step 4;

FIG. 9 is a flowchart showing a rule applied when the worker B completes the work of step 5;

FIG. 10 is a flowchart showing a rule applied when the worker B completes the work in step 9;

FIG. 11 is a flowchart showing a rule applied when a worker C completes the work of step 6;

FIG. 12 is a flowchart showing a rule applied when a worker C completes the work of step 17;

FIG. 13 is a flowchart showing a rule applied when the worker C completes the work of step 8;

FIG. 14 is a graph showing simulation results of a straight line, a U-shaped line (without cooperation), and a U-shaped line (with cooperation), respectively.

Claims (4)

[Claims] 1. A production simulation method for simulating a human-centered production line system in which at least mutual assistance is performed between workers, wherein each worker moves to the next each time the work is completed. Creating a rule for defining the place to be performed and the work to be performed next, and performing a simulation based on the situation information including the work progress status of each worker and the current situation of the work, and the rules described above. There is a production simulation method. 2. The production simulation method according to claim 1, wherein the rule for at least one worker uses predetermined information of the situation information as a variable and describes a conditional expression including the variable. 3. The production simulation method according to claim 2, further comprising the step of optimizing the variable so as to improve the variation in the working time among the workers. 4. The rule is created based on a process in charge for each worker, a process for helping another worker for each worker, and a work time for each process. 3. The production simulation method according to 1.