JPH11285716A - Method for controlling physical distribution for manufacturing line - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control method of physical distribution for minimizing the generation of material shortage and overload in each treating equipment by moving materials from on a line to an off-line part or inversely. SOLUTION: In the control method of physical distribution for manufacturing line for controlling the physical distribution by executing the simulation of the physical distribution on the manufacturing line including a finishing process, in-process state in each process about a specified period in future is simulated and, from that result, whether the movement of the materials due to delay on the line is necessary or not is judged (S2). By judging the idle state of the line from the finishing process on the upstream side, in-process materials in the off-line part are filled up in idle time bands (S3-S5) and, by repeating (S7, S8) the simulation (S6) of the in-process state in each process about the specified period in future, the final result of the simulation is obtained and also, based on this result, the information of the movement of the material between the line and the off-line part is indicated (S9).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distribution control method for a production line or the like provided with a refining facility on the downstream side.

[0002]

2. Description of the Related Art For example, in a production line in which a rolling mill is provided on the upstream side and a refining facility is provided on the downstream side, processing pitches in the upstream and downstream facilities are different. Therefore, the timing of material supply and processing may not be synchronized, and the efficiency of the production line may be reduced. Therefore, a physical distribution simulation method for simulating the actual movement of an article by a computer has been developed, and several techniques have been proposed.

For example, Japanese Patent Laying-Open No. 63-207414 proposes an apparatus for controlling the distribution of a processing object between a plurality of processing apparatuses interconnected by a transfer apparatus. Here, based on the processing schedule data to which the in-process in-process data, the in-transit processing object data, and the out-of-specification processing necessity data have been added, the processing equipment for the manufacturing plant for steel plate etc. Information on the status of the in-process occurrence at the entry side of the is predicted, and the in-process forecast data is created by the physical distribution simulator.

[0004] Next, based on the created work-in-progress prediction data, each processing object of the processing-scheduled data stored in the processing-scheduled data storage device is set so as to minimize running out of material and occurrence of overload in each processing facility. About the processing order,
For example, the processing object is replaced with a processing object having a different manufacturing route. Eventually, it is a device that issues instructions to the work instruction device to control the physical distribution.

Japanese Unexamined Patent Publication No. Hei 5-266001 proposes a simulation method of logistics management in which a coil transfer schedule is planned for each lot and simulation is performed for each product. According to this technique, a database is created based on the amount of a lot in a work-in-process and the next process, and detailed information for each coil. In this way, a simulation is performed and the physical distribution is controlled in real time.

[0006] Further, in this technique, in particular, a simulation is incorporated into the physical distribution management by automatically judging the occurrence of a lack of material or an overflow of the storage space. As a characteristic, it claims that it is possible to predict and prevent the timing and the period (amount) of the occurrence of shortage of materials and overflow of the storage space.

Japanese Unexamined Patent Publication (Kokai) No. 7-164035 proposes a physical distribution control method for preventing a production line from being stopped due to material accumulation. In this technique, by moving material from the line off-line or vice versa,
Material retention is prevented.

For example, for some zones of the line, the retention density of the material is calculated from the existing quantity of the material in the zone and the maximum possible quantity. The congestion state of the material is determined from the calculated residence density and the moving speed of the material measured by a speedometer provided at the entrance of the zone.
Based on the result (congestion situation), the material in the zone is jumped off-line or vice versa.

[0009]

However, when rolling and refining processes are directly connected in a line, such as a steel pipe production line, the conventional technology cannot optimize the logistics. For example, rolling may have to be stopped due to traffic congestion in the refining process.

The technique described in Japanese Patent Application Laid-Open No. 63-207414 merely deals with changing the order of the materials on the line, and does not consider moving the material from the line to offline or vice versa. . Therefore, in the case of a production line in which the rolling and refining processes are directly connected in a line, the processing pitch may not be in time for each refining process and material overflow may occur, or conversely, idle time may occur in each process. There is.

[0011] With this conventional technique, it is impossible to optimize the physical distribution including the work of transporting the material between the line and the off-line. In addition, there is a problem that it is not possible to optimize the production order of the materials so as to minimize the amount of overflow.

The technique described in Japanese Patent Application Laid-Open No. 5-266001 basically deals with a work in progress, but the work in progress mainly deals with the presence or absence of a storage overflow. For this reason, it is possible to predict the occurrence of a line stoppage due to the overflow of the storage space. However, when idle time occurs in each process, the work of transferring the material from the offline to the line is not considered.

Therefore, it is impossible to optimize the physical distribution including the work of transferring the material between the line and the off-line. In addition, there is a problem that it is not possible to optimize the production order of the materials so as to minimize the amount of overflow.

In the technique described in Japanese Patent Application Laid-Open No. H7-164035, the material is moved from the line to offline or vice versa in order to prevent the material from staying. However, since this operation is performed in real time, even if it is optimal at each time point, it cannot be said that the entire series of operations is necessarily optimized.

The present invention solves the above-mentioned problems of the prior art, and takes into consideration the movement of material from a line to an off-line or vice versa. It is an object of the present invention to provide a physical distribution control method capable of minimizing the flow and a physical distribution control method capable of minimizing an overflow amount due to traffic congestion.

[0016]

The above object is achieved by the following invention.

According to a first aspect of the present invention, there is provided a distribution control method for a production line which controls the distribution by simulating the distribution of the production line including the refining process. From the results, it is determined whether or not it is necessary to move the material offline due to line congestion.From the upstream refining process, the vacancy status of the line is determined and the offline work material is embedded in the vacant time zone. A manufacturing method characterized by repeatedly simulating the process status of a process to obtain a final simulation result and displaying information on material movement between a line and an off-line based on the final simulation result. This is a distribution control method for the line.

In the present invention, the predetermined period in the future is
This is the period targeted by the simulation for the physical distribution control, and can be arbitrarily determined. The simulation of the in-process state of each process is performed by a generally known method. For example, the technique described in the above-mentioned Japanese Patent Application Laid-Open No. 7-164035 can be used.

According to the simulation of the in-process situation,
If there is line congestion, it is necessary to move the overflowing material offline. In this case, the material that has moved offline becomes an offline work-in-process. After that, a vacant time zone is searched from the upstream refining process. If there is a vacant time zone, an off-line work-in-progress material is searched and embedded therein, and the work-in-process situation of each process is simulated again for a predetermined period in the future.

The final simulation result is obtained by repeating the search for the free time zone and the simulation until the final refining process. Based on the result of the final simulation, information on the movement of the material between the line and the offline is displayed. By displaying the information display to the operator of the transfer device such as a crane, the transfer operation can be promoted.

According to a second aspect of the present invention, when a lot of material requiring offline transfer exceeds a certain ratio, the range of replacement of the manufacturing sequence is expanded and the lot is divided based on a predetermined rule. A method for controlling distribution of a production line according to a first aspect of the present invention, wherein a production sequence that minimizes materials that need to be moved off-line is determined by changing the production sequence of lots.

The present invention provides a method for minimizing material that needs to be moved off-line, ie, the amount of overflow. According to the simulation of the work-in-progress situation, if a lot with an overflow rate exceeding a certain rate occurs in the lot of the overflow lot, the production order of the lot is replaced and the lot is divided based on rules. The rules here are
Setting of the range to replace lots, lot split conditions,
And the method of combination of these is determined. By repeating these processes as necessary, the overflow amount can be minimized.

As described above, in the present invention, the physical distribution control is performed in consideration of moving the material from the line to the off-line or vice versa. As a result, it is possible to prevent material shortage in each processing facility and minimize occurrence of overload.
Furthermore, by changing the manufacturing order and dividing the lot, the amount of material overflow due to overload in each processing facility can be minimized.

According to a third aspect of the present invention, when the manufacturing order is changed, the optimum manufacturing order is obtained by using the difference in the cycle time and the equipment change time. It is a control method.

According to the present invention, the difference between the cycle times, that is, the difference between the equipment cycle time and the production cycle time is calculated, and the production order is changed so as to minimize the difference. At the same time, the reordering time of the manufacturing apparatus due to the insertion of lots having different sizes is also calculated, and the manufacturing order is changed so that these two are minimized. As a result, it is possible to prevent the rearrangement time from being increased in order to match the cycle time, and conversely, the cycle time from being inconsistent in order to reduce the rearrangement time, and the production time from being lost.

[0026]

FIG. 1 is a flowchart showing an example of an embodiment of the present invention. This series of processing starts at regular intervals.

First, in step S1, the rolling and refining process specification data 11 is read as information arranged in the rolling order for each lot, and also the cycle time and the change time data are read.

Next, in step S2, the progress of each process is simulated for a predetermined period in the future. At this time, if overflow occurs due to line congestion, the data of the corresponding material is transferred to an offline work-in-process data file together with information indicating the process.

From step S3, a repetition loop is entered, and an empty time zone is searched for the most upstream refining process for the first time. Here, if there is a free time zone, the next step S
In step 4, an offline work-in-progress material that can be raised (put on the line) in the idle time zone is searched from the offline work-in-process data file in accordance with the priority order. In step S5, the data of the searched off-line work-in-progress material is embedded in the free time zone.

After the processing of the above steps, step S6
Then, as in step S2, the progress of each process is simulated for a predetermined period in the future. At this time, if overflow occurs due to line congestion, the data of the corresponding material is transferred to an offline work-in-process data file together with information indicating the process. Step S7 is a step of performing repetition determination. If the refinement process in which the simulation has been performed is the final process, the process exits the loop. Otherwise, the process proceeds to the next refinement process and returns to step S3.

After performing the simulation up to the final refining process, in step S9, the simulation result is displayed on the terminal 13 installed on the ground or overhead crane or the like. The display contents are at least the estimated time of off-line dropping occurrence in each refining process, and the expected line rise on-line from off-line.

Looking at the displayed contents, the operator of the ground and overhead cranes can make advance preparations such as dropping the material and raising the line. For example, it is possible to advance the standby of the overhead crane in the corresponding processing step, to confirm the location of the offline work material to be line-up (offline placement frame, etc.), to facilitate preparations, etc., and to improve the efficiency of transport work. Become.

FIG. 2 is a block diagram showing an example of the embodiment of the present invention. Here, a steel pipe manufacturing factory is assumed. In the heating furnace 1, a billet as a material is heated, and the heated and softened material is sent to a rolling mill 2 and rolled. The rolled material after the rolling is transported to the finishing equipment 41 by the transport device 31.

Thereafter, in this example, the wafers are conveyed to the adjusting devices 42 and 43 by the conveying device 32. Thereafter, it is processed further by a refining facility (not shown) on the downstream side and shipped as a product. In each of these steps, an overhead crane 5 and an off-line placing frame 6 are arranged, and the material is taken offline and the material is raised on the line.

The physical distribution simulator device 8 obtains necessary data from the processing schedule data storage device 9 and performs a simulation. From the processing-scheduled data storage device 9, the specification data of the rolling and refining processes for the material to be rolled in a predetermined period in the future is input to the simulator 10. The cycle time / replacement time of each process of the corresponding attribute is obtained from the cycle time / replacement time storage device 12, and the simulator 10 simulates the work-in-progress situation of each facility for a predetermined period in the future.

At this time, the data of the material overflowed due to the line traffic is transferred to the offline work material data storage device 11. Each time the simulation is completed once, the vacant time zone of each process is determined by the simulator 10. From the process on the upstream side, offline work-in-process data that is being processed in the corresponding process is searched from the offline work-in-process data file in accordance with the priority order, embedded in a free time zone, and simulated again.

Based on the result of the final simulation in which this operation is performed in order from the upstream side to the final step, information on the estimated time of material falling off-line in each step is displayed on the terminal 13.

FIG. 3 is a flowchart showing an example of the embodiment of the present invention in the case where the amount of overflow due to traffic congestion is minimized. This series of processing starts at regular intervals.

First, steps S1 and S2 are executed in the same manner as shown in FIG. Next, in step S10, an off-line work-in-process data overflowing due to traffic congestion is searched, and an overflow rate for each lot is calculated. This represents the ratio of the number of overflows to the parameter (number) of each lot.

Next, in step 11, if there is a lot whose overflow rate is equal to or more than a certain value (α%), or if step 12-D described later has not been performed, the process proceeds to step 12. Otherwise, it is determined that the overflow amount has been optimized, and the process proceeds to step S3 shown in FIG. 1 described above.

In step 12, the manufacturing order of lots (overlapping lots) whose overflow rate is equal to or more than a certain value is changed based on rules, and the lots are divided. The outline is as shown in FIG. 4, and the details will be described below.

First, in step 12-A, FIG.
As shown in (2), replacement is performed within the range of lots of the same size. As a rule in that case, for other lots,
Cycle time difference: (Maximum cycle time in refining equipment)-(Manufacturing cycle time) is calculated, and the above-mentioned lot is inserted before the lot that minimizes this to change the manufacturing order.

For example, for certain size lots A, B, C,
D, E, F and lots U, V,
It is assumed that W, X, Y, and Z are arranged in the order of ABCDEF @ UVWXYZ. Here, a mark “↑” indicates a work of reassembling the manufacturing apparatus according to the size change. If the overflow rate of the lot B becomes equal to or more than a predetermined value, a lot having the smallest difference in cycle time is searched for among other lots ACDEF of the same size. If it is, for example, the lot E, the corresponding lot B is inserted before the lot E, and the manufacturing order is changed to ACDBEF @ UVWXYZ.

In this way, the load is leveled by passing the lot before the corresponding lot through the refining equipment with minimum traffic congestion. After the end of step 12-A, the manufacturing specifications are changed based on the new manufacturing order, and the process returns to step S1 shown in FIG.

Thereafter, through each step, step S11
If the process branches to step S12 again,
Go to -B. In step 12-B, the lot is divided as shown in FIG. Split, for example, 2 divided by n ₁ or more, so that the three portions n ₂ or more. The cycle time difference is calculated in the same size lot range as in step 12-A. Here, a lot of the number equal to the number of divisions is selected from the smallest one of the calculated values, and the divided lot is inserted before the lot to change the manufacturing order.

For example, as a result of step 12-A,
The production order of the lot is ACDBEF @ UVWXYZ, but the case where the overflow rate of the lot B has reached a certain value or more still corresponds to the processing of this step. This time, the lot B is divided into two sub lots, B ₁ and B ₂ . It is assumed that a lot E having the smallest cycle time difference is searched among other lots ACDEF of the same size. Further, it is assumed that a similar search was performed on other lots excluding the lot E, and it was determined that the lot F was obtained. In this case, one sub-lot B ₁ of the divided lot is inserted before the lot E, and the other sub-lot B ₂ is inserted before the lot F, and the manufacturing order is changed to ACDB ₁ EB ₂ F ↑ UVWXYZ. Next, the process proceeds to the subsequent processing as in step 12-A.

Thereafter, when the process branches to step S12 again, the process proceeds to step 12-C. In step 12-C, as shown in FIG. 4 (c), a search is made back and forth to a range of lots having different sizes, and a difference in cycle time is calculated as in step 12-A. In this case, select the lot that minimizes both the calculated value and the time required to change the manufacturing equipment due to the insertion of lots of different sizes, insert the relevant lot before that lot, and change the manufacturing order. .
However, if the replacement time of the manufacturing apparatus is equal to or longer than a certain value (β minutes), the replacement is not performed.

For example, as a result of the above-described step 12-B,
The production order of the lot was ACDB ₁ EB ₂ F @ UVWXYZ, but the overflow rate of lot B was still lower (sub lot B
₁ and B ₂ the combined) if equal to or greater than a predetermined value, corresponds to the process in this step. This time, another lot U of another size
Suppose that a lot with the smallest difference in cycle time is searched in VWXYZ and found to be lot Y. Further U
When the lot B is inserted before any of VWXYZ, it is assumed that the lot that minimizes the reordering time of the manufacturing apparatus is searched and found to be the lot X.

Next, it is determined whether the lot B or the lot X is optimally inserted before the lot Y or the lot X. This is determined so that the values of both the difference between the cycle times and the time for changing the manufacturing apparatus are optimal in each case. For example, it can be determined using a weighted average of the two values. As a result, it is assumed that the lot X optimizes both the difference in the cycle time and the time for changing the manufacturing apparatus.
In this case, the lot B is inserted before the lot X, and the manufacturing order is changed to ACDEF \ UVW \ B \ XYZ. However, if the total time of the reassembling work (↑) of the manufacturing apparatus is equal to or more than a certain value (β minutes), the replacement is not performed. Next, the process proceeds to the subsequent processing as in step 12-A.

Thereafter, when the process branches to step S12 again, the process proceeds to step 12-D. In step 12-D, similar to step 12-B, as shown in FIG.
In addition to dividing the lot, similarly to step 12-C, the manufacturing order is changed by searching forward and backward to a range of lots having different sizes. Specifically, the divided lot is inserted before a plurality of other lots, and the manufacturing order is changed.

For example, as a result of the above-described step 12-C,
The production order of the lot is ACDEF \ UVW \ B \ XYZ, but the case where the overflow rate of the lot B becomes a certain value or more again corresponds to the processing of this step. This time,
Similar to Step 12-B, divides the lot B into two sub-lots of B _1, B _2.

Next, as in step 12-C, an insertion point for optimizing both the difference in cycle time and the time for changing the manufacturing apparatus is obtained. As a result, it is assumed that the optimum insertion position is the lot X. Next, excluding the lot X, an insertion point for optimizing both the difference in cycle time and the time for changing the manufacturing apparatus is obtained again. If the result is lot Y, lot B ₁ is inserted before lot X and lot B ₂ is inserted before lot Y. Eventually, the production order is ACDE
F ↑ UVW ↑ B ₁ ↑ X ↑ B ₂ ↑ YZ. However, if the total time of the reassembling work (↑) of the manufacturing apparatus is equal to or more than a certain value (β minutes), the replacement is not performed. Then, Step 12-
The process proceeds to subsequent processes in the same manner as A.

In FIG. 2, the simulator 10 makes individual determinations, changes the manufacturing specifications of the data storage device 9 to be processed, and performs the simulation again in FIG.

[0054]

EXAMPLE As a result of implementing the present invention in a steel pipe factory by the method shown in FIG. 2 described above, it was possible to greatly reduce overtime hours. For example, in the finishing process, the rolling time is 16 hours per day, whereas in the conventional operation, the material that is taken off-line is processed, so that the operating time is 19 hours, that is, 3 hours after rolling. Met. In the operation according to the method of the invention, the operating time is 16.5 hours, ie 0.5 hours after rolling.
Overtime work has been reduced and overtime has been significantly reduced from 3 hours to 0.5 hours.

Further, as a result of performing the same operation by the method shown in FIG. 3 described above, the operation time was further reduced by 0.2 hour to 16.3 hours due to the decrease in the overflow material, and 0.3 hours after rolling. Overtime work has been completed, and overtime work has been further reduced to 0.3 hours.

[0056]

According to the present invention, since the physical distribution control is performed in consideration of the transfer of the material from the line to the off-line or vice versa, it is possible to prevent the running out of the material in each processing equipment,
Overload can be minimized. Furthermore, shortage of objects to be processed in each of the refining steps is avoided, so that, for example, when the upstream step is a rolling step, it is possible to greatly reduce overtime after rolling. In addition to this, the manufacturing order is changed and the lot is divided using the mode for minimizing the overflow amount, so that further reduction can be achieved. In addition, there is an effect that the overall operation efficiency is improved, the lead time is shortened, and the delivery delay is reduced.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an example of an embodiment of the present invention.

FIG. 2 is a block diagram showing an example of an embodiment of the present invention.

FIG. 3 is a flowchart showing another example of the embodiment of the present invention.

FIG. 4 is a flowchart showing rules for changing a manufacturing order and dividing a lot.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating furnace 2 Rolling mill 5 Overhead crane 6 Offline placing frame 8 Logistics simulator device 9 Processing scheduled data storage device 10 Simulator 11 Offline work-in-process material data storage device 12 Cycle time / rearrangement time storage device 13 Terminal 31, 32 Transport device 41, 42, 43 Refinement equipment

Claims (3)

[Claims] In a production line distribution control method for controlling distribution by simulating the distribution of a production line including a refining process, the work in progress of each process is simulated for a predetermined period in the future, and the line congestion is calculated based on the simulation result. To determine if it is necessary to move the material off-line, and from the upstream refining process, determine the vacancy of the line and embed the offline work in the vacant time zone. Repeating the simulating process to obtain a final simulation result, and displaying information on material movement between the line and the off-line based on the final simulation result. Method. 2. In the case where a lot of material requiring offline transfer exceeds a certain ratio, the range of production sequence replacement is expanded and the lot is divided based on a predetermined rule. 2. The distribution control method for a production line according to claim 1, wherein the production order that minimizes the materials that need to be moved off-line is determined by replacing the production order. 3. The distribution control method for a production line according to claim 1, wherein, when the production order is changed, an optimum production order is obtained by using a difference in cycle time and a time for changing the equipment.