JPH0620898A - Product line process start controlling method - Google Patents

Abstract

PURPOSE:To enable products to be efficiently fed, lessened in cost, and enhanced in productivity by a method wherein it is judged that a first process can be started so as to make a product line maximal in operation rate not exceeding a time limit set between a certain process and a following process in a product line. CONSTITUTION:A time limit Ti is provided for the quality of product between a process 1 of processing time ti and a following process 2 of processing time ti+1 out of a series of processes where products are separately fed. Also, a time limit T. is provided between the process 2 and a following process 3 of processing time ti+2. In this case, when a product is in a buffer just before the process 1, it is judged if the first process 1 can be made to start so as to be maximal in operation rate not exceeding a time limit T1 set between the process 1 and the process 2 and also a time limit Ti+1. By this setup, products are prevented from being disused exceeding a time limit and can be efficiently fed, lessened in cost, and enhanced in productivity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a production line process start control method, and more particularly to a production line for efficiently flowing products when there is a time limit between processes such as semiconductor production and multilayer substrate production. The present invention relates to a process start control method.

[0002]

2. Description of the Related Art Conventionally, for example, step (i) and step (i +)
When there is a time limit between the process (i) and the process (i + 1) and the process (i + 2), whether or not the process (i) can be started is determined by a worker on site. .

[0003]

Since the judgment of the process start in the above-described conventional process start method is left to the operator, the buffer having a time limit for temporarily placing the product which cannot start the process is set. There is a problem in that the products inside cannot be completely processed and are discarded over the time limit, or conversely there is a gap between the products and the products cannot be efficiently flowed.

An object of the present invention is to perform a step (i) of a certain processing time t _{i in} a production line and a subsequent processing time t.
_{i + 1} of step (i + 1) time limit T _i the quality of the product exceeds the time limit will have to be made to discard poor between there is, step (i + 1) and following thereafter processing time t _{i + 2} step (i + 2) exceeds the limit time between when the quality of the product is made will have to be discarded limit time T _{i + 1} bad, step (i) product in the buffer of the immediately preceding step without exceeding the time limit T _i between (i) and step (i + 1), step (i + 1) and step (i + 2) without exceeding the time limit T _{i + 1} between the step (i) Under the condition that the process (i) is undertaken so that the operation rate is maximized, it is possible to solve the above-mentioned drawbacks by limiting whether or not the process (i) can be undertaken. Efficient flow of products as there are no products that are discarded over time Therefore, it is an object of the present invention to provide a production line process start control method capable of reducing the disposal rate, shortening the production lead time, reducing the cost and improving the productivity.

[0005]

According to the production line process start control method of the present invention, a product is flowed one by one, and the product is processed at a certain processing time t _{i in} a production line consisting of a series of a plurality of processes.
If the time limit is exceeded between the step (i) of step (i) and the step (i + 1) of the subsequent processing time t _{i + 1} , the quality of the product deteriorates and the time T must be discarded.
_If there is _i and if this time limit is exceeded between the step (i + 1) and the step (i + 2) subsequent to the processing time t _{i + 2} , the quality of the product is deteriorated and must be discarded. If there is a time T _{i + 1} , then the step (i)
The product in the immediately preceding buffer does not exceed the time limit T _i between the step (i) and the step (i + 1), and the product between the step (i + 1) and the step (i + 2) is The step (i) is started under the condition that the step (i) is started so that the operation rate of the step (i) is maximized without exceeding the time limit T _{i + 1.} It is characterized by determining whether it is possible.

[0006]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 shows the process, processing time, and time of one embodiment of the present invention.
It is a figure which shows the definition of a time limit and the number of servers. In FIG. 1, it is assumed that the production line is composed of a series of a plurality of processes, and that the product flows through the line one by one. A certain process in the production line is defined as process (i) 1, and the processes subsequent thereto are process (i + 1) 2 and process (i).
The step following (+1) 2 is step (i + 2) 3, and the buffer (i) is provided between step (i) 1 and step (i + 1) 2.
4. It is assumed that there is a buffer (i + 1) 5 between the step (i + 1) 2 and the step (i + 2) 3. What is a buffer?
It is a place to temporarily store products that cannot start the process. Further, the processing times of the process (i) 1, the process (i + 1) 2 and the process (i + 2) 3 are set to t _i , t _{i + 1} and t _{i + 2} , respectively, and the process (i +) is completed after the process (i) 1 is completed.
1) T _i is the time limit until the start of 2 (if the time limit is exceeded, the quality of the product deteriorates and the product must be discarded), the process (i + 1) 2 ends after the process (i + 1) 2 ends. Let the time limit until the start be T _{i + 1} .
Further, the numbers of servers in step (i) 1, step (i + 1) 2 and step (i + 2) 3 are S _i , S _{i + 1} and S _{i + 2} , respectively. The number of servers is a number that can perform processing in parallel (corresponding to the number of service windows in queuing theory), and corresponds to, for example, the number of facilities or workers.

Please refer to the flow chart showing the procedure of this embodiment shown in FIG. 2, the flow chart showing the details of condition A in FIG. 2 shown in FIG. 3, and the flow chart showing the details of condition B in FIG. 2 shown in FIG. The processing procedure of this embodiment will be described.

It is checked whether or not the number of servers S _i in the step (i) 1 is free, and if the number of servers S _i in the step (i) 1 is not available, the process (i) 1 cannot be started. No
Wait until it is free (step 11). When step (i) 1 free server number S _i occurs, the average processing time of a few per server, i.e. to find the longest step of tact, t _i
/ S _i , t _{i + 1} / S _{i + 1} and t _{i + 2} / S _{i + 2} are compared (step 12).

When the tact t _i / S _i is the longest, that is, the formula (t _i / S _i ) ≧ (t _{i + 1} / S _{i + 1} ) and the formula (t
_i / S _i ) ≧ (t _{i + 2} / S _{i + 2} ) holds, the number of servers S _i in step (i) _{1 is} less than the number of servers S _{i + 1 in} step (i + 1) 2, that is, expression S _i <S _{i + 1} (step 13), and the number of servers S _i in process (i) 1 is process (i + 2)
If the number of servers is less than S _{i +2 of} 3, that is, the formula S _i <S _{i +2} (step 15), it is possible to start step (i) 1 (step 22). If the number of servers S _i in the step (i) ₁ is not less than the number of servers S _{i + 1 in the} step (i + 1) 2, that is, the expression S _i <S _{i + 1} is not satisfied, the condition A described later is satisfied. Wait (step 14), and if the number of servers S _i in the process (i) 1 is less than the number of servers S _{i + 2 in the} process (i + 2) 3, that is, the formula S _i <S _{i + 2} (step 15). , Process (i) 1 can be started (step 22). Further, if the number of servers S _i in the step (i) 1 is not less than the number of servers S _{i + 2 in the} step (i + 2) 3, that is, the formula S _i <S _{i + 2} is not satisfied, the condition B described later is satisfied. Wait until the process is completed (step 16), and then step (i) 1 can be started (step 22).

When the tact t _{i + 1} / S _{i + 1} is the longest, that is, the formula (t _{i + 1} / S _{i + 1} )> (t _i / S _i ) and the formula (t _{i +} 1 / S _{i +). 1} ) ≧ (t _{i + 2} / S _{i + 2} ) holds, the number of servers S _{i + 1 in} the process (i + 1) 2 is equal to the process (i +
2) Less than the number of servers S _{i + 2 of} 3, that is, the formula S _{i + 1} <S
_{If i + 2} (step 17), wait until condition A described later is satisfied (step 19), and then process (i)
One move is possible (step 22). Process (i + 1) 2
The number of servers S _{i + 1} is process (i + 2) 3 number of servers S _{i + 2}
If not less than, that is, if the expression S _{i + 1} <S _{i + 2} is not satisfied, wait until condition B described later is satisfied (step 18), and wait until condition A described later is satisfied (step 19). After that, step (i) 1 can be started (step 22).

When the tact t _{i + 2} / S _{i + 2} is the longest, that is, the expression (t _{i + 2} / S _{i + 2} )> (t _i / S _i ) and the expression (t _{i +} 2 / S _{i +). 2} )> (t _{i + 1} / S _{i + 1} ) holds, waits until a condition A described later is satisfied (step 2
0), and further waits until the condition B described later is satisfied (step 21), and then step (i) 1 can be started (step 22).

The condition A will be described in detail with reference to FIG. The t described in the following description represents the time elapsed since the start of each process (or buffer). First, after starting the process (i) 1, it is determined where the S _{i + 1-} th product is (step 31). The step (i) 1 is where there is the _{Si + 1-} th product after the start of step (i) 1, and the formula t−t
_{If i + 1} ≧ 0 is satisfied, the condition A is terminated, and if not satisfied, the process returns to step 31 (step 32). Step (i) where from embarked on 1 of S _{i + 1} th product a buffer (i) 4, and terminates the condition A if satisfied formula _{(t i + t) -t i} + 1 ≧ 0 If not established, the process returns to step 31 (step 33). After starting step (i) 1, S
_The place where the _{i + 1-} th product is present is the step (i + 1) 2, and the condition A is terminated if the expression (t _i + T _i + t) −t _{i + 1} ≧ 0 is satisfied, and if not satisfied, the process returns to step 31. (Step 34). The step (i) 1 and the buffer (i) 4 are where there are S _{i + 1} products after the step (i) 1 is started.
And neither of the steps (i + 1) 2, Condition A
To finish.

The condition B will be described in detail with reference to FIG. The t described in the following description represents the time elapsed since the start of each process (or buffer). First, after starting the process (i) 1, it is determined where the _{Si + 2nd} product is (step 41). The step where there is the (S _{i + 2)} th product after starting the process (i) 1 is the process (i) 1, and the formula t−t
_{If i + 2} ≧ 0 is satisfied, the condition B is terminated, and if not satisfied, the process returns to step 41 (step 42). Step (i) where from embarked on 1 of S _{i + 2-th} product a buffer (i) 4, and terminates the condition B if satisfied formula _{(t i + t) -t i} + 2 ≧ 0 If not established, the process returns to step 41 (step 43). After starting step (i) 1, S
_The place where the _{i + 2nd} product is present is the process (i + 1) 2, and the condition B is ended if the expression (t _i + T _i + t) −t _{i + 2} ≧ 0 is satisfied, and if not satisfied, the process returns to step 41. (Step 44). Step (i) where from embarked on 1 of S _{i + 2-th} product is 5 buffer (i + 1), them satisfied the formula _{(t i + T i + t} i + 1 + t) -t i + 2 ≧ 0 If the condition B is satisfied, the process returns to step 41 if not satisfied (step 45). After starting step (i) 1, S _{i + 2}
The step (i + 2) 3 is where the th product is, and if the expression (t _i + T _i + t _{i + 1} + T _{i + 1} + t) −t _{i + 2} ≧ 0 is satisfied, the condition B is terminated and must be satisfied. Step 41
Return to. After starting the process (i) 1, there is a _{Si + 2nd} product where the process (i) 1, the buffer (i) 4, the process (i + 1) 2, the buffer (i + 1) 5 and the process (i +).
2) If neither of 3 is satisfied, the condition B ends.

[0014]

As described above, according to the present invention,
Between the one by one in the flow of products with a medium production line comprising the product of a series of a plurality of step processing time t _i steps (i) and the processing time t _{i + 1} steps following thereafter (i + 1) If this time limit is exceeded, there is a time limit T _i that the quality of the product deteriorates and must be discarded, and the process (i + 1) and the subsequent process time t _{i + 2} (i).
+2), if there is a time limit T _{i + 1 at} which product quality deteriorates and must be discarded if this time limit is exceeded, the product in the buffer immediately before step (i) is called process (i). step (i + 1) without exceeding the time limit T _i between, and without exceeding the time limit T _{i + 1} between the step (i + 1) and step (i + 2), the operation of step (i) Under the condition that the process (i) is undertaken so that the rate is maximized, it is judged that it is possible to undertake the process (i), and then the process is discarded beyond the time limit. Since there are no lost products and the products can be efficiently flown, the disposal rate is reduced, the production lead time is shortened, the cost is reduced, and the productivity is improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a definition of a process, a processing time, a time limit, and a number of servers according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the procedure of this embodiment.

FIG. 3 is a flowchart showing details of condition A in FIG.

FIG. 4 is a flowchart showing details of condition B in FIG.

[Explanation of symbols]

1 step (i) 2 step (i + 1) 3 step (i + 2) 4 buffer (i) 5 buffer _{(i + 1) t i,} t i + 1, t i + 2 processing time T _i, T _{i +} 1, the time limit S _i , S _{i + 1} , S _{i + 2} Number of servers

Claims (1)

[Claims] 1. A one by one in the processing time t _i which flows the product with a medium production line comprising the product of a series of a plurality of process steps (i) and the processing time t _{i + 1} steps following thereafter (i
+1), there is a time limit T _i for which the quality of the product deteriorates and must be discarded if this time limit is exceeded, and the process (i + 1) and the subsequent processing time t _{i + 2} When this time limit is exceeded between the step (i + 2) and the product, there is a time limit T _{i + 1} that the quality of the product becomes poor and must be discarded. Step (i) and the step (i)
Without exceeding the time limit T _i between +1), and, without exceeding the limit time T _{i + 1} between the step (i + 1) and the step (i + 2), the step (i ), It is judged whether or not it is possible to undertake the step (i) under the condition that the step (i) is undertaken so as to maximize the operation rate. Process start control method.