JP2000099111A - Production control method and device - Google Patents

Abstract

(57) [Summary] The present invention allows a high-priority product to flow with a minimum processing wait time. An apparatus monitoring unit monitors an operation status of a group of apparatuses, and a product process management unit manages at least a product processing procedure, a processing priority, and a current process progress.
A processing time prediction unit 14 for predicting a processing time of a product based on at least a processing condition of the product managed by the product process management unit 12;
Progress and processing time prediction unit 14 managed by
Product progress prediction unit 13 for predicting the progress of the product from the current time to a predetermined time later based on the machining time predicted by
When the processing of the product is completed, a high-priority product is selected by the device groups 3 and 5 based on the process progress status managed by the product process management unit 12 and the product progress predicted by the product progress prediction unit 13. Next, a work control unit 11 for deciding to process is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a production control method applied to a plurality of products having different priorities using a plurality of devices, for example, a job shop type production line for processing or machining semiconductor wafers and a device therefor. About.

[0002]

2. Description of the Related Art In the production of products having complicated processing steps and different processing procedures depending on product types, such as semiconductor wafer processing and mechanical processing, effective use of expensive manufacturing equipment (hereinafter abbreviated as equipment) is attempted. For this reason, a job shop system is adopted in which similar devices are gathered in one place to form a device group.

In general, a plurality of products having different processing priorities are mixed in a product flowing through the job shop type production line. Among a plurality of products having different priorities, those which need to complete processing in a short period of time with priority given to processing include, for example, products with late delivery, development prototypes, and the like.

In particular, in recent products having a short product life cycle, manufacturing prototypes for processing process verification and engineering samples for customer submission in a short period of time in parallel with mass-produced products improves product competitiveness. It has become a very important point for.

FIG. 4 is an external view of a production line for manufacturing semiconductor wafers using such a job shop system. This production line shows two of a plurality of processes, that is, a pre-process 1 and a post-process 2 for convenience. In the pre-process 1, an apparatus group 3 and a work-in-progress shelf 4 are provided. 2
Also, a device group 5 and an in-process shelf 6 are provided.
An inter-shop transfer 7 is provided between the in-process shelves 4 and 6 in the post-process 2.

In such a production line, the products are processed by the apparatus group 3 in the pre-process 1, and the products after the processing are transferred from the intra-shop transfer in the pre-process 1 to the post-process 7 through the inter-shop transfer 7. 2 arrives at the device group 5. The arrival of this product is asynchronous with the processing timing of the post-process 2. Also, the processing time differs depending on the product.

The product arriving at the post-process 2 is processed by the device group 5 of the post-process 2, and the processed product is transferred from the intra-shop transfer in the post-process 2 to the inter-shop transfer. After that, it is further conveyed to the subsequent process.

Here, the control of the processing order and the processing start time of the products in each step (pre-step 1 and post-step 2) is performed as follows. (a) When the processing with the selected device is completed, the operator selects the product with the highest priority from among the in-process products that have arrived, and starts processing with this device. (b) If a high-priority product is likely to arrive from the pre-process 1, contact the operator in the pre-process 1 and wait for the product to arrive with the equipment open, for example, to process the product. Judge the order and machining start time. (c) If you want to ensure that high-priority products flow in a short period of time, assign a dedicated progress manager to the product and receive the product in the next process according to the progress of the product. In some cases, adjustment of the start of processing is performed immediately.

FIG. 5 is a Gantt chart showing an example of control of the processing order and processing start time of such products. In this control, the devices N-1 and N-2 are provided in the device group 3 of the pre-process 1, and the devices M-1, M-2, M
-3, and there are products A, B, C, and D as in-process products between the pre-process 1 and the post-process 2, of which the product A is a high-priority product.

To briefly explain the flow of the product, first, as the in-process product in the post-process 2, the product D has already arrived, and then the product C processed by the device N-2 in the pre-process 1 is Arrives, and then the product B processed by the device N-1 arrives,
Next, the urgent product A processed by the device N-2 has arrived.

On the other hand, in the post-process 2, first, the processing of the product in the device M-3 is completed and the processing of the in-process product D is started, and then the processing of the product in the device M-1 is completed. The processing of the in-process product C is started, and then the processing of the product in the device M-2 is completed, and the processing of the in-progress product A is started prior to the already arrived product B.

[0012]

However, in the above-described control method, the following problem occurs because the operator or the progress manager of the appointment determines the machining order and the machining start time. For example, in machining or semiconductor wafer processing, the processing time is long, for example, 10 hours or more. When a high-priority product arrives after processing of an already-arrived product has started, for example, when a product A shown in FIG. 5 arrives, processing of this product must wait until the immediately preceding processing ends. become. For this reason, the construction period of a product with a high priority is extended.

In the above control methods (b) and (c), the arrival time of a product is predicted to reduce the processing waiting time of a high-priority product. However, it is based on the machining time estimated by the operator based on his / her experience and intuition, and is not fixed by the operator. For this reason, if the prediction of the arrival time of a product with a high priority is erroneously predicted, the apparatus is unnecessarily opened and waits, which leads to a decrease in production volume.

In the above control method (b), the communication with the operator in the previous process is not always successful, and a high-priority product suddenly arrives and may not be processed immediately. Further, in the above control method (c), although the adjustment is performed every time by a dedicated person, the management cost is high and the product cost is increased.

As described in, for example, JP-A-8-236413 and JP-A-9-148210, there is a method of controlling the processing order in each step by a computer. No method is disclosed for minimizing the processing waiting time of a product having a very high priority. Accordingly, an object of the present invention is to provide a production control method and an apparatus therefor that allow a high-priority product to flow with a minimum processing wait time.

[0016]

According to a first aspect of the present invention, there is provided a production control method for controlling the production of a plurality of products having different priorities using a plurality of devices. Is reported, the highest priority product selected from the in-process products that have already arrived, and the new product that arrives from the current time to the earliest processing start time at which the next product can be processed as soon as possible. This is a production control method that compares a product with the highest priority selected from among the hanging products and determines that the product with a higher priority is to be processed next by the processing end device.

According to a second aspect of the present invention, in the production control method for controlling the production of a plurality of products having different priorities by using a plurality of devices, when any one of the devices reports a processing end, Procedure for selecting the highest priority product from the already arrived in-process products as the first candidate to be processed next, and the processing when this first candidate product is processed immediately by the processing end device A procedure for determining the end time;
The earliest processing start time at which the next product can be started earliest is obtained based on the processing end time of the device that processes the first candidate product and the device that finishes the earliest among the devices that are currently processing. A procedure, a procedure for predicting a work-in-progress product newly arriving from the current time to the earliest processing start time, and a second process for processing a product having the highest priority from the work-in-progress products predicted in this step next. A procedure for selecting a candidate as a candidate, a procedure for comparing the priorities of the first candidate product and the second candidate product, and determining that the higher priority product is to be processed next by the processing end device; Is a production control method.

According to a third aspect of the present invention, there is provided a production control apparatus for controlling the production of a plurality of products having different priorities by using a plurality of apparatuses. A process procedure, a process condition, a process priority, and a product process management unit that manages a process progress status of each of the products at the present, and a process of each product based on at least a process condition of each product managed by the product process management unit. A processing time prediction means for predicting the processing time, and a progress of the product from a current time to a predetermined time later based on at least the process progress status managed by the product process management means and the processing time predicted by the processing time prediction means. Upon receiving the processing end from the operation status of each device from the product progress prediction means to be predicted and the device monitoring means, the process progress status managed by the product process management means , A work control unit that determines a machining sequence with its machining start time of the product higher priority based on the progress of the predicted product at the progress predicting means is a production control system having a.

According to a fourth aspect of the present invention, in the production control apparatus according to the third aspect, the processing time predicting means records the processing result data edited based on the operation status of the apparatus monitored by the apparatus monitoring means. It has a function to predict the processing time of a product based on actual data.

According to a fifth aspect of the present invention, in the production control device according to the third aspect, the product progress predicting means is configured to execute the processing from the current time to the earliest processing start time at which processing of the product can be started earliest in each device. It has the function of predicting the in-process products that will arrive.

According to a sixth aspect of the present invention, in the production control apparatus according to the third aspect, the product progress predicting means predicts the progress of the product at the current time managed by the product process managing means and the processing time predicting means. Based on the processed processing time, the remaining processing time of the currently processed product obtained by the work control means, the product transfer time or the processing waiting time, the processing of the product in the respective devices is started earliest from the current time next. It has the function of predicting the in-process products that arrive by the earliest possible processing start time.

According to a seventh aspect of the present invention, in the production control device according to the third aspect, the work control means, when a device completion report is received from any one of the devices from the device monitoring means, the product process management means. A function of selecting a product with the highest priority as a first candidate to be processed next from among in-process products already arriving at the current time managed by the processing time, and a processing time predicted by the processing time prediction means. A function for obtaining a processing end time when the product selected as the first candidate is immediately processed by the processing end device based on the processing, and a processing of the device for processing the first candidate product predicted by the processing time prediction means. Based on the end time and the processing end time of each apparatus that is processing at the current time, the earliest processing start time at which processing is completed earliest among the apparatuses and processing of the next product can be started earliest is determined. A function of selecting a product with the highest priority from among in-process products arriving from the current time predicted by the product progress prediction means to the earliest processing start time as a second candidate to be processed next; A function of comparing the priorities of the first candidate product and the second candidate product, and determining that the higher priority product is to be processed next by the processing end device.

According to the eighth aspect of the present invention, in the production control apparatus according to the third aspect, the operation control means immediately determines the priority of the first candidate product and the second candidate product and the processing waiting time. It has a function to determine the product to be processed.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. The same parts as those in FIG. 4 are denoted by the same reference numerals, and detailed description thereof will be omitted. FIG. 1 is a configuration diagram of a production control device applied to a production line for manufacturing semiconductor wafers using a job shop method.

The apparatus monitoring unit 10 performs a first process and a second process.
Has a function of constantly monitoring the operation status of each of the device groups 3 and 5, ie, the start and end of processing.
When it is detected that the processing of a certain device in
It has a function of reporting to the work control unit 11 that the next processing at this time has become possible. The apparatus monitoring unit 10 also monitors the start and end of the transfer of a product (semiconductor wafer), and has a function of reporting these events to the product process management unit 12 together with the start and end of processing. are doing.

The product process management section 12 records in advance the product type, processing priority and processing procedure for each product. In this processing procedure, the apparatus groups 3 and 5 used for processing in each step, the processing conditions thereof, and the transport equipment used for transporting the product are recorded. In addition, the product process management unit 12 records and updates the progress of the product with the time at which it has occurred at each processing start, processing end, or conveyance start, and conveyance completion of each product reported from the device monitoring unit 10, In addition, it has a function of calculating the transport time and the processing waiting time, and reporting them to the product progress prediction unit 13.

The processing time estimating unit 14 includes the product process management unit 1
The processing time of each product is predicted based on the processing conditions and the like of each product managed in Step 2. The product type, process,
In addition to the data of the standard processing time for each processing condition, the processing time is calculated for each of the processing start and end events detected by the apparatus monitoring unit 10, and this is edited for each product type, process, and processing condition. Has a function of recording as actual result data, that is, processing time history data. The processing time prediction unit 14 has a function of searching for processing time history data from the type, process, and processing conditions of a product to be processed, and statistically processing the searched data to calculate an average processing time. .

The product progress predicting unit 13 includes the product process managing unit 1
Process progress and processing time prediction unit 1 managed by 2
4 has a function of predicting a work-in-progress product arriving at the process after a predetermined time from the current time, for example, from the current time to the earliest processing start time at which processing on the product can be started earliest based on the processing time predicted by Step 4. I have.

More specifically, the product progress predicting section 13 totals the transport time calculated by the product process managing section 12 for each transport device, and also totals the processing waiting time for each of the device groups 3 and 5, and records the respective history data. And the average processing time is calculated by statistically processing the history data.

The product progress predicting section 13 stores the product progress status at the current time managed by the product process managing section 12, the processing time prediction data predicted by the processing time predicting section 14, and the work described later. It has a function of calculating the progress of the product from the current time to the earliest processing start time based on the remaining processing time of the currently processed product obtained by the control unit 11 and the history data of the product transport time or the processing waiting time. ing.

The calculation of the progress for each product is as follows. (1) When the product is being processed, predicted next process arrival time = current time + remaining processing time + transport time (2) When the product is waiting for processing Next predicted process arrival time = current time + average processing wait time-processing Waiting time result + machining time + transport time (3) When the product is being transported Next predicted arrival time of the next process = current time + average transport time-transport time actual The work control unit 11 Upon receiving the processing end from the operation statuses of 3 and 5, processing of a high priority product is performed based on the process progress status managed by the product process management unit 12 and the product progress predicted by the product progress prediction unit 13. Has a function to determine.

More specifically, the work control unit 11 includes the device monitoring unit 1
If there is a report of the end of processing from any one of the device groups 3 and 5 from 0, the highest priority is given to the in-process products already arriving at the current time managed by the product process management unit 12. And a device that has reported the completion of processing the product selected as the first candidate based on the processing time predicted by the processing time prediction unit 14, and the function of selecting the product with the highest product as the first candidate for processing next. A function for obtaining a machining end time when machining is performed immediately, and a machining end time of an apparatus for machining a first candidate product predicted by the machining time estimating unit 14 and machining by each apparatus performing machining at the current time. A function for obtaining the earliest processing start time at which processing can be completed earliest and the next product can be started earliest based on the end time, and the earliest processing start from the current time predicted by the product progress prediction unit 13 A function of selecting a product with the highest priority from the in-process products arriving at the process by the hour as a second candidate to be processed next; and a priority between the first candidate product and the second candidate product. It has a function of comparing the degrees and determining the next processing of a product with a higher priority by the apparatus which has reported the processing completion.

Next, the operation of the apparatus configured as described above will be described with reference to the work control flowchart shown in FIG. The device monitoring unit 10 constantly monitors the processing start and the processing end of each of the device groups 3 and 5 in the pre-process 1 and the post-process 2, and when detecting that the processing of a certain device in each of the device groups 3 and 5 is completed, The fact that processing at this point is possible is reported to the work control unit 11. Also, the device monitoring unit 10
Also monitors the start and end of product transport, and reports these events to the product process management unit 12 along with the start and end of processing.

In step # 1, the work control section 11 determines whether or not any one of the apparatuses 3 and 5 has reported the end of processing from the apparatus monitoring section 10, and there is a report of the end of processing. Then, the process proceeds to step # 2, and the product with the highest priority is selected as the first candidate to be processed next from the in-process products that have already arrived at the current time managed by the product process management unit 12. .

For example, as shown in FIG. 3, four devices “1” to “4” operate as a device group 5 in the post-process 2, and each of the products A, B,
When the processing of the device “2” is completed at the current time while C has arrived from the previous process 1 at times t ₁ , t ₂ , and t ₃ , the work control unit 11 has already arrived at the current time. The product with the highest priority, such as the product B, is selected from the in-process products A, B, and C as the first candidate to be processed next.

Next, the processing time prediction unit 14 calculates the type, process, processing conditions, and processing time of the product B as the first candidate managed by the product process management unit 12 based on the type of each product, The processing time history data edited for each process and processing condition is searched and statistically processed to calculate an average processing time.

Next, in step # 3, the work control unit 11 obtains the processing end time of the product B selected as the first candidate based on the processing time predicted by the processing time prediction unit 14.

Here, the work control unit 11 sets each of the devices "1" and "3" other than the device "2" that has finished processing at the current time.
About "4", these devices "1", "3", "4"
When the product to be processed is determined and the processing start time is determined, the processing end time is predicted and recorded by the processing time prediction unit 14.

Accordingly, the work control unit 11 executes step # 4
, The apparatus “2” for processing the first candidate product B and the apparatuses “1” and “3” for processing at the current time
The processing end times of “4” are compared, and these apparatuses “1” to “1” are compared.
The earliest processing start time at which processing is finished earliest and processing of the next product can be started earliest among "4" is determined.

In this case, as shown in FIG.
It is selected that the device "3" finishes processing the earliest among "4" to "4", and the processing end time of the device "3" is determined as the earliest processing start time.

Next, the product progress predicting section 13 processes the in-process products D and E arriving at the post-process 2 from the current time to the earliest processing start time based on the process progress status managed by the product process managing section 12. Predict. Since the product F arrives after the earliest processing start time, it is excluded from the prediction target.

The product progress predicting section 13 calculates the progress of the product at the current time managed by the product process managing section 12, the remaining processing time of the currently processed product obtained by the work control section 11 described later, Further, the progress of the product from the current time to the earliest processing start time is calculated based on the history data of the product transport time or the processing waiting time. As a result, such as the product D in FIG. 3, E is calculated as arriving at time t _4, t _5, respectively.

Next, in step # 5, the work control unit 11 selects the in-process products D and E arriving at the post-process 2 from the current time predicted by the product progress prediction unit 13 to the earliest processing start time. The product with the highest priority, for example, product E, is selected as the second candidate to be processed next.

Then, the work control unit 11 obtains the processing end time of the product E selected as the second candidate based on the processing time predicted by the processing time prediction unit 14. Next, in step # 6, the work control unit 11 compares the priorities of the first candidate product B and the second candidate product E, and determines which priority is higher.

As a result of this determination, if the second candidate product E has a higher priority than the first candidate product B, the work control unit 11 proceeds to step # 7 and proceeds to step # 7. Is determined to be processed, and the apparatus “2” is put into a waiting state until the product E arrives, and the processing is immediately started by the apparatus “2” simultaneously with the arrival of the product E.

On the other hand, if the first candidate product B has a higher priority than the second candidate product E, the work control unit 11
Moves to step # 8, determines that the first candidate product B is to be processed, and causes the device “2” to immediately start processing.

Then, the work control unit 11 calculates the processing end time in the device “2” by adding the time when the processing of the product E is started or the time when the processing of the product B is started to the predicted processing time. And record this.

Then, the work control section 11 returns to step # 1 again. As described above, in the above-described embodiment, when the end of processing is reported from the device groups 3 and 5 in the post-process 2, the product with the highest priority among the in-process products that have already arrived in the post-process 2 And the highest priority product among the in-process products arriving from the current time to the earliest processing start time at which the next product can be processed the earliest.
Since the high-priority product is processed immediately, as described above, if the priority of the arriving product E is high, the processing can be started with a minimum waiting time, and the already arriving in-process product B If the priority is high, processing can be started immediately, and a high priority product can be flown stably with a minimum waiting time without depending on the experience and intuition of the operator.

Further, since the product to be automatically flown is determined by the work control, a dedicated person for adjusting the progress of the product with high priority is not required, and the product cost can be reduced. As a result, it is possible to shorten the development period of development prototypes that are manufactured in parallel with mass production products, shorten the development period of new products, and deliver engineering samples to customers in a short period of time. Can improve your competitiveness.

The present invention is not limited to the above embodiment, but may be modified as follows. For example, in the above-described embodiment, the process progress of the product is predicted using the past performance data. However, the present invention is not limited to these, and the process progress of the product is simulated by comparing the processing capability of the device group with the processing time. Alternatively, the process progress may be predicted with higher accuracy.

In the above embodiment, the product to be processed next is determined by comparing the absolute value of the priority of the product already in process with the priority of the product arriving from now.
The selection of the product to be processed next is the trade-off between the loss of waiting for the product to arrive in the future until the earliest processing start time of the equipment group and the loss of waiting for the processing of the product already in process to wait for the product to arrive in the future. It may be determined to be off. In this case, a processed product can be selected based on both the product priority and the product processing waiting time.

[0052]

As described above in detail, according to the present invention, it is possible to provide a production control method and apparatus capable of flowing a high priority product with a minimum processing wait time.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment in which a production control device according to the present invention is applied to a production line for manufacturing semiconductor wafers using a job shop method.

FIG. 2 is a flowchart of a work control unit in the apparatus.

FIG. 3 is a diagram showing an example of a processing order and a processing start time of a device group by operation control of the device.

FIG. 4 is an external view of a production line of a job shop system.

FIG. 5 is a Gantt chart showing an example of control of a product processing order and a processing start time.

[Explanation of symbols]

 1: Pre-process, 2: Post-process, 3, 5: Device group, 4, 6: In-process shelf, 7: Conveyance between shops, 10: Device monitoring unit, 11: Work control unit, 12: Product process management unit, 13: Product progress prediction unit, 14: Processing time prediction unit.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3C042 RJ12 5B049 BB07 CC21 CC31 EE12 EE33 EE59 5H004 GB15 KC23 5H215 AA06 AA20 BB07 BB20 CC07 CX01 GG09

Claims (8)

[Claims] 1. A production control method for controlling the production of a plurality of products having different priorities by using a plurality of devices, wherein when any one of the devices reports a processing end, the process has already arrived. The highest priority product selected from existing in-process products and the highest priority selected from new in-process products arriving from the current time to the earliest processing start time at which the next product can be processed as soon as possible. A production control method comprising: comparing a product having a higher priority with a product having a higher priority; 2. A production control method for controlling the production of a plurality of products having different priorities by using a plurality of devices, wherein if any one of the devices reports a processing end, the device has already arrived. Selecting the highest priority product as the first candidate to be processed next from the in-process products, and the processing end time when the first candidate product is immediately processed by the processing end device. The next procedure can be started as soon as possible based on the required procedure and the processing end time of the device that processes the first candidate product and the processing end time of the device that finishes processing the earliest among the devices that are currently processing. A procedure for obtaining an earliest processing start time, a procedure for predicting a work-in-progress product newly arriving from the current time to the earliest processing start time, and a procedure of the highest priority among the work-in-progress products predicted in this step. Selecting a second product as a second candidate to be processed next, comparing the priorities of the first candidate product and the second candidate product, and selecting the higher priority product as the processing end device. And a procedure for deciding to process next in a production control method. 3. A production control device for controlling the production of a plurality of products having different priorities using a plurality of devices, wherein a device monitoring means for monitoring an operation status of each of the devices; A product process management means for managing processing conditions, a processing priority, and a process progress status of each of the products at present; processing of each of the products based on at least the processing conditions of each of the products managed by the product process management means; Processing time prediction means for predicting time, at least from the current time to a predetermined time later from the current time based on the process progress status managed by at least the product process management means and the processing time predicted by the processing time prediction means A product progress estimating means for estimating the progress of the product; Said step progress that are managed by means and working control means for determining a processing order and its processing start time of the product high priority based on the progress of the products that are predicted by the product progress prediction means,
A production control device comprising: 4. The processing time prediction means records actual processing data edited based on the operation status of the apparatus monitored by the apparatus monitoring means, and predicts the processing time of the product based on the actual data. 4. The production control device according to claim 3, wherein the production control device has a function of performing the operation. 5. The product progress predicting means has a function of predicting an in-process product arriving from a current time to an earliest processing start time at which processing of the product can be started earliest in each of the devices. 4. The production control device according to claim 3, wherein: 6. The product progress prediction means, wherein the progress of the product at the current time managed by the product process management means, the processing time predicted by the processing time prediction means, From the current time based on the remaining processing time of the product currently being processed, the transport time of the product or the processing waiting time, and then from the earliest processing start time at which processing on the product can be started earliest in each of the devices. 4. The production control device according to claim 3, wherein the production control device has a function of predicting an in-process product to arrive. 7. The work control means, upon receiving a report of processing completion from any one of the devices from the device monitoring means, has already arrived at the current time managed by the product process management means. A function of selecting a product with the highest priority from among in-process products as a first candidate to be processed next, and selecting the first candidate based on the processing time predicted by the processing time prediction means. A function for obtaining a processing end time when the processed product is immediately processed by the processing end device; and a processing end time and a current time of an apparatus for processing the first candidate product predicted by the processing time prediction means. A function for obtaining the earliest processing start time at which processing can be completed earliest and the next product can be started earliest among the respective devices based on the processing end time at each of the devices performing processing A function of selecting a product with the highest priority as a second candidate to be processed next from among in-process products arriving from the current time predicted by the product progress prediction means to the earliest processing start time; A function of comparing the priorities of the first candidate product and the second candidate product, and determining that the high-priority product is to be processed next by the processing end device. The production control device according to claim 3, wherein 8. The work control means has a function of determining the product to be processed immediately based on the priority of the first candidate product and the second candidate product and a processing waiting time. 4. The production control device according to claim 3, wherein: